JP2002145499A - Tension control device for sheet and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent the dislocation of a printing aim by effectively suppressing both a fine tension fluctuation of a sheet and a wide tension fluctuation. SOLUTION: A tension control device for the sheet comprises an radial feed roller 7; a dancer mechanism 10 to energize a dancer roller 12; a roller position detecting means 16 to detect position displacement of the dancer roller; a tension detecting means 18 to detect the conveyance tension of the sheet 1; and a rotation speed control means 19 to control the rotation speed of the radial feed roller 7 so that the dancer roller 12 is returned to a reference position and control the rotation speed of the radial roller such that the tension fluctuation of the sheet 1 is suppressed. In a dead zone region where at least the dancer roller 12 is held in a reference position, rotation speed control of the radial feed roller 7 according to a detecting signal of the tension detecting means 18 is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet material tension control device for controlling the tension of a sheet material conveyed by a conveying mechanism provided in a printing machine or the like.

[0002]

2. Description of the Related Art Conventionally, as shown in, for example, FIG. 5, an unwinding roll 2 in which a sheet material 1 is wound in a roll shape, and a drawer 3 for extracting the sheet material 1 from the unwinding roll 2 with a predetermined tension. And a plurality of printing units 5a to 5n having printing plate cylinders 4 for sequentially applying and printing a plurality of colors of ink to the sheet material 1 supplied by the drawer 3, and a printing unit 5n at the last stage. As shown in FIG. 4, in a printing press provided with a winding unit 6 for winding the printed sheet material 1 with a predetermined tension, an infeed roller 7 for transporting the sheet material 1 and a power such as a timing belt mechanism are provided. A drive motor 9 for rotationally driving the infeed roller 7 via a transmission mechanism 8; a dancer machine for absorbing slack of the sheet material 1 derived from the infeed roller 7 and suppressing elongation of the sheet material 1 And 10 have been made be provided in the lead-out portion 3.

The dancer mechanism 10 swings the dancer roller 12 with a dancer roller 12 disposed between the infeed roller 7 and the guide roller 11 and a support shaft 13 provided at a base end as a fulcrum. A support arm 14 for freely supporting and a drive cylinder 15 for pushing the support arm 14 are provided. By urging the support arm 14 in accordance with the driving force of the drive cylinder 15, the dancer roller 12 is fixed to a predetermined position. Is pressed against the sheet material 1 with a pressing force of.

When the transport tension of the sheet material 1 fluctuates greatly during splicing of the sheet material 1 or the like, the drive cylinder 15
The swinging displacement of the support arm 14 and the dancer roller 12 in response to the urging force causes the slack and elongation of the sheet material 1 to be absorbed. Further, when the rocking displacement of the dancer roller 12 is detected by the roller position detecting means 16 composed of a potentiometer or the like, a control signal corresponding to this is output to the drive motor 9 to reduce the rotational speed of the infeed roller 7. By adjusting,
Control is performed to return the dancer roller 12 to a reference position such as a neutral position, whereby the tension of the sheet material 1 downstream of the dancer roller 12 is adjusted to be substantially constant.

[0005]

As described above, the swing displacement of the dancer roller 12 is detected and the infeed roller 7 is detected.
By adjusting the rotation speed of the dancer roller 12
Is held at the reference position, the tension fluctuation of the sheet material 1 due to disturbance or the like can be suppressed to some extent, but the tension fluctuation in the range where the swing displacement of the dancer roller 12 does not occur, Specifically, the fluctuation of the rotation resistance of each guide roller for guiding the sheet material 1 or the change of the sheet material 1
There is a problem that it is not possible to suppress minute fluctuations in tension due to a slight change in the speed of the driving roller for transporting the sheet.

That is, the drive cylinder 15 has a predetermined operating resistance, and the pressing force of the dancer roller 12 urged by the drive cylinder 15 and the reaction force of the sheet material 1 acting in response thereto. If the deviation does not exceed a certain value, the dancer roller 12 does not swing and displace.
Despite slight fluctuations in the transport tension of the sheet material 1, the fluctuations in the tension could not be suppressed. For example, when the transport tension of the sheet material 1 is set to 100N, the reference value of the transport tension is set to 3.
If the deviation of about 5N to 5.0N or more does not occur, the dancer roller 12 does not swing and displace, so that the tension fluctuation of less than 3.5N could not be suppressed.

Therefore, there is a problem in that it is not possible to prevent a shift in printing position, that is, a so-called misregistration, caused by expansion and contraction of the sheet material 1 in response to a slight change in tension of the sheet material 1. Was. In particular, recently, there has been a tendency to reduce the thickness of the packaging sheet material and the like from the viewpoint of environmental protection and the like, and the sheet material 1 greatly expands and contracts in response to a slight change in the tension of the sheet material 1. Therefore, it is desired that the minute tension fluctuation of the sheet material 1 be effectively suppressed.

[0008] A tension detecting means for detecting a minute fluctuation of the tension of the sheet material 1 is provided, and the rotational speed of the infeed roller 7 is controlled based on the detected value to suppress the fluctuation of the tension. Although it is conceivable to suppress the above-mentioned minute tension fluctuation, it is difficult to execute control following this when a large tension fluctuation occurs at the time of splicing of the sheet material 1 or the like in such a configuration. And
There is a problem that it is impossible to prevent the tension of the sheet material 1 from being extremely reduced to cause the sheet material 1 to be loosened, or to prevent the sheet material 1 from being greatly stretched due to an excessive tension.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a sheet material tension control apparatus and a printing machine capable of effectively suppressing both a minute tension fluctuation and a large tension fluctuation of a sheet material. It is intended to provide.

[0010]

The invention according to claim 1 is
An infeed roller that is rotated by a drive motor to convey the sheet material, and a dancer mechanism that urges a dancer roller installed in the sheet material conveyance path to absorb sheet material slack and suppress sheet material elongation A roller position detecting means for detecting a displacement of the dancer roller, a tension detecting means for detecting a conveying tension of the sheet material, and a dancer roller displaced from a reference position according to a detection signal of the roller position detecting means. When it is confirmed, the rotation speed of the infeed roller is controlled so as to return the dancer roller to the reference position, and it is confirmed that the sheet material has changed in tension in response to the detection signal of the tension detecting means. Rotation speed control means for controlling the rotation speed of the in-feed roller so as to suppress the fluctuation of the tension when the rotation is performed. , At least in the dancer roller is held at the reference position dead zone, which is constituted so as to perform a rotational speed control of the infeed roller in accordance with the detection signal of the tension detecting means.

[0011] According to the above configuration, when the transport tension of the sheet material greatly fluctuates, for example, at the time of splicing the sheet material, the dancer roller is displaced from the reference position. The control to return the dancer roller to the reference position in accordance with the displacement amount of the dancer roller is performed by the rotation speed control means while preventing the expansion and contraction from occurring. The conveyance tension of the sheet material on the side is adjusted to be substantially constant. Further, when it is confirmed that slight tension fluctuation of the sheet material occurs in response to the detection signal of the tension detecting means in the dead zone of the control in which the dancer roller is held at the reference position, the tension fluctuation is detected. By controlling the rotation speed of the in-feed roller so as to suppress the above, the minute tension fluctuation is effectively suppressed.

According to a second aspect of the present invention, in the sheet tension controlling apparatus according to the first aspect, the rotation speed control means causes a displacement of the dancer roller in response to a detection signal of the roller position detection means. A reference value storage unit for storing the detected value of the tension detecting means at the time when it is confirmed that there is no reference value as a reference value of the transport tension, and a reference value of the transport tension stored in the reference value storage unit and the tension detecting means. A control value setting unit for setting a control value of the rotation speed of the in-feed roller corresponding to the detected deviation from the conveyance tension of the sheet material.

According to the above configuration, it is confirmed that the pressing force of the dancer roller urged by the drive cylinder and the corresponding reaction force of the sheet material are balanced and no displacement occurs in the dancer roller. In this case, the detected value of the tension detecting means at this point is stored as a reference value of the transport tension. Thereafter, a control value of the rotation speed of the infeed roller is set in a control value setting section based on a deviation between the reference value of the transport tension and a detection value of the tension detecting means, and the input value is set based on the control value. By adjusting the rotation speed of the feed roller, fluctuations in the tension of the sheet material can be effectively suppressed.

According to a third aspect of the present invention, there is provided the sheet material tension control apparatus according to the first or second aspect, further comprising a drive motor including an AC servomotor directly connected to the infeed roller.

According to the above configuration, the rotation speed of the infeed roller directly driven by the AC servomotor is:
Since the control is performed quickly and accurately in accordance with the control signal output from the rotation speed control means, the fluctuation in the tension of the sheet material is effectively suppressed.

According to a fourth aspect of the present invention, there is provided a printing apparatus comprising: a drawer provided with the sheet material tension control device according to the third aspect; and a printing plate cylinder for applying ink to the sheet supplied from the drawer. Machine directly connected to the printing plate cylinder
It is provided with a plate cylinder drive motor composed of a servomotor.

According to the above configuration, the plate cylinder driving motors composed of AC servomotors are provided in the respective printing units, and the respective printing plate cylinders are individually driven. Therefore, as shown in FIG. Like a general printing press having a main motor 27 that collectively drives the printing plate cylinders 4 arranged in the units 5a to 5n, and a power transmission mechanism 28 that transmits the driving force to each printing plate cylinder. In addition, the sheet material does not fluctuate in tension due to the operation resistance of the power transmission mechanism 28 and the like, and the occurrence of misregistration due to this tension fluctuation is effectively prevented.

[0018]

FIG. 1 shows an embodiment of a sheet material tension control device according to the present invention. The tension control device includes an in-feed roller 7 for conveying the sheet material 1;
A drive motor 17 composed of an AC servomotor directly connected to the in-feed roller 7 and a dancer roller 12 installed in the sheet material conveying path are urged to absorb the slack of the sheet material 1 and to remove the sheet material 1. As shown in FIG. 3, a dancer mechanism 10 that suppresses elongation and a downstream side of the installation portion of the dancer mechanism 10 in the conveying direction of the sheet material 1 and an upstream side of the printing unit 5a located at the most upstream side, as shown in FIG. There is provided a tension detecting means 18 provided and a rotation speed control means 19 for controlling the rotation speed of the infeed roller 7 so as to suppress the fluctuation of the tension of the sheet material 1.

The dancer mechanism 10 includes a guide roller 1
1, a dancer roller 12, a support arm 14, a drive cylinder 15, a roller position detecting means 16 and the like. The support arm 14 is urged in accordance with the driving force of the drive cylinder 15 so that the dancer roller 12 When the sheet material 1 is pressed against the sheet material 1 by the pressing force described above and a large tension variation occurs at the time of splicing of the sheet material 1 or the like, the support arm 14 and the dancer roller 12 swing and displace according to the urging force of the drive cylinder 15. By doing so, the sheet material 1
It is configured to absorb slack and elongation.

The tension detecting means 18 includes a pick-up roller 20 disposed on the conveying path of the sheet material 1 and a strain gauge type or inductance type tension detector 21 provided at a rotation support portion of the pick-up roller 20. The tension detector 21 detects the transport tension of the sheet material 1 corresponding to the reaction force acting on the pickup roller 20 when the sheet material 1 is transported, and outputs a detection signal to the rotation speed control means 19. It is configured as follows.

As shown in FIG. 2, the rotation speed control means 19 includes a discriminator 22 for discriminating whether or not the dancer roller 12 has been displaced in accordance with a detection signal of the roller position detection means 16. If it is confirmed by the determination unit 22 that the position displacement has not occurred, the detected value of the tension detecting means 18 at that time is stored as a reference tension, and the dancer roller 12 set in advance to a neutral position or the like is stored. Value storage unit 23 for storing the reference position of
And a control value setting unit 24 for setting a control value for feedback controlling the rotation speed of the infeed roller 7.
Are provided.

The discriminating section 22 is urged by the driving cylinder 15 to press the dancer roller 1 pressed against the sheet material 1.
2 and the reaction force of the sheet material 1 corresponding thereto is balanced, so that the dancer roller 12 is stopped for a certain time or more near the neutral position by the roller position detecting means. 16 is determined according to the detection signal, it is determined that the position of the dancer roller 12 is not displaced.
Is configured to determine that a positional displacement has occurred.

The reference value storage unit 23 detects the tension when the discriminating unit 22 determines that the dancer roller 12 has been stopped near the neutral position for a certain period of time or more after the start of the printing press. The conveyance tension of the sheet material 1 detected by the means 18 is stored as a reference value. When it is determined that the displacement of the dancer roller 12 has occurred in the determination unit 22,
Thereafter, when the dancer roller 12 stops in the vicinity of the neutral position for a certain period of time or more, the reference value of the transport tension stored in the reference value storage unit 23 is used as the detection signal of the tension detection unit 18. It will be updated accordingly.

The control value setting section 24 determines the reference position of the dancer roller 12 stored in the reference value storage section 23 when the determination section 22 determines that the dancer roller 12 is displaced. Position detecting means 16
Is determined from the current position of the dancer roller 12 and the control value of the rotation speed of the infeed roller 7 corresponding to this deviation is set. A control signal corresponding to this control value is transmitted to the infeed roller 7 is output to the drive motor 17 that rotationally drives the drive motor 7.

The above-mentioned rotation speed control value is determined by the dancer roller 1
2 is a value for performing feedback control of the rotation speed of the infeed roller 7 so as to correct the position displacement of the dancer roller 12 to return to the reference position, and to calculate the position displacement amount of the dancer roller 12 from a preset map. A corresponding control value is read out, or the control value is calculated based on various control conditions.

For example, if the transport tension of the sheet material 1 becomes smaller than the reference value for some reason, the driving cylinder 1
5, the pressing force of the dancer roller 12 becomes larger than the reaction force of the sheet material 1, and the dancer roller 1 is moved in a direction for absorbing the slack of the sheet material 1 (the direction of arrow A in FIG. 1).
2 oscillates, the control value is set in a direction to increase the rotation speed of the infeed roller 7, thereby increasing the transport tension of the sheet material 1 and increasing the dancer roller 1.
2 can be returned to the reference position near the neutral position.

Conversely, when the transport tension of the sheet material 1 becomes larger than the reference value, the pressing force of the dancer roller 12 urged by the drive cylinder 15 becomes smaller than the reaction force of the sheet material 1, and Since the dancer roller 12 swings in a direction in which the elongation of the sheet material 1 is suppressed (the direction of the arrow B in FIG. 1), the control value is set in a direction in which the rotation speed of the in-feed roller 7 is reduced. , The dancer roller 12 can be returned to the reference position near the neutral position.

The control value setting section 24 is provided with a discriminating section 2
2, regardless of whether it is determined that a displacement has occurred in the dancer roller 12 or not, the reference value of the transport tension stored in the reference value storage unit 23 and the sheet material 1 detected by the tension detection unit 18. By determining the deviation of the transport tension from the current value and setting the control value of the rotation speed of the infeed roller 7 corresponding to the deviation, at least the dead zone in which the dancer roller 12 is held at the reference position can be adjusted. The rotation speed of the feed roller 7 is controlled.

In other words, when the control value setting unit 24 confirms that a slight tension fluctuation occurs without causing the displacement of the dancer roller 12 and the conveyance tension of the sheet material 1 fluctuates from a reference value. In, a control value for controlling the rotation speed of the infeed roller 7 in a direction to suppress the fluctuation of the transport tension and to suppress the fluctuation of the tension is set.

When the printing machine having the tension control device for the sheet material 1 configured as described above is activated, the state in which the conveying speed of the sheet material 1 is stabilized and the dancer roller 12 is stopped near the neutral position. The determination unit 22 determines that
At this point, the reference value of the transport tension of the sheet material 1 is stored in the reference value storage unit 23 in accordance with the detection signal of the tension detecting means 18.

Thereafter, when it is confirmed by the determination section 22 that the dancer roller 12 has been displaced from the reference position in response to the detection signal of the roller position detection means 16, the dancer roller 12 is returned to the reference position. By controlling the rotation speed of the infeed roller 7 in the direction to return the dancer roller 12 to a preset reference position, the control for adjusting the transport tension of the sheet material 1 on the downstream side thereof to be substantially constant can be performed. This is executed by the rotation speed control means 19.

Further, in the dead zone where the dancer roller 12 is held at the reference position, that is, in the region where the rotation speed control corresponding to the displacement of the dancer roller 12 is not executed, a slight change in the tension of the sheet material 1 occurs. Occurs, the control value setting unit 24 calculates the amount of change in the transport tension based on the detection signal of the tension detecting means 18 and the reference value of the transport tension, and calculates the variation in the transport tension. The rotational speed of the in-feed roller 7 is controlled so as to be corrected, and the rotational speed control unit 19 performs control to prevent the influence of the minute tension fluctuation from affecting the downstream side of the tension detecting unit 18. Will be.

As described above, the in-feed roller 7 that is rotated and driven by the drive motor 17 and conveys the sheet material 1,
A dancer mechanism 10 that urges a dancer roller 12 installed in the conveyance path of the sheet material 1 to absorb the slack of the sheet material 1 and suppresses the elongation of the sheet material 1, and detects a displacement of the dancer roller 12. Roller position detecting means 1
6 and the rotation speed of the infeed roller 7 so as to return the dancer roller 12 to the reference position when it is confirmed that the dancer roller 12 has been displaced from the reference position in response to the detection signal of the roller position detection means 16. Is provided with the rotation speed control means 19 for controlling the rotation of the sheet material 1. When the transport tension of the sheet material 1 fluctuates greatly during the splicing of the sheet material 1 or the like, the dancer roller 12 is oscillated and displaced. Thus, it is possible to prevent the sheet material 1 from being elongated or contracted. Further, by controlling the rotation speed of the infeed roller 7 in accordance with the displacement amount of the dancer roller 12 detected by the roller position detection means 16, the dancer roller 12 is returned to the reference position, and The transport tension of the sheet material 1 can be adjusted to be substantially constant.

A tension detecting means 18 for detecting the transport tension of the sheet material 1 is provided, and the transport tension of the sheet material 1 fluctuates from the reference value in at least the dead zone where the dancer roller 12 is held at the reference position. When it is confirmed according to the detection signal of the tension detecting means 18 that a slight change in the tension has occurred, the rotation speed controlling means 1
9, the rotation speed of the in-feed roller 7 is controlled to correct the minute fluctuation of the transport tension. Therefore, the minute tension fluctuation is effectively suppressed, and the influence is affected by the printing units 5a to 5n, etc. Can be prevented.

Therefore, even when the sheet material 1 is formed of a material having a large expansion / contraction ratio or the thickness of the sheet material 1 is reduced, the misregistration of the printing position due to the above-mentioned fluctuation in tension is effectively prevented. The occurrence of printing defects can be suppressed. According to an experiment conducted by the present inventor, when a sheet material 1 made of a polypropylene film having a thickness of about 20 μm or a non-stretched polypropylene soft PVC film is conveyed at a tension of 50N to 100N, the tension variation is 0.5N. And the amount of misregistration could be suppressed to less than 0.05 mm. On the other hand, if the speed control based on the detection signal of the tension detecting means 18 is not performed, the amount of register shift cannot be suppressed to 0.1 mm or less, and the speed control based on the detection signal of the tension detecting means 18 cannot be performed. It has been confirmed that by performing the above, the misregistration can be significantly suppressed.

Further, as shown in the above embodiment, the dancer roller 1
2, a reference value storage unit 23 for storing the detected value of the tension detecting means 18 at the time when it is confirmed that no positional displacement has occurred, as a reference value of the transport tension, and the transport value stored in the reference value storage unit 23. The control value setting unit 19 for setting a control value of the rotation speed of the infeed roller 8 corresponding to a deviation between the reference value of the tension and the conveyance tension of the sheet material 1 detected by the tension detection unit 18 performs the rotation speed control. Means 19
When the pressing force of the dancer roller 12 urged by the drive cylinder 15 and the corresponding reaction force of the sheet material 1 are balanced, the detected value of the tension detecting means 18 is conveyed. It can be stored as a reference value of the tension.

Therefore, even when the material of sheet material 1, environmental conditions, and the like change, the reference value of the conveyance tension can always be set to an appropriate value, and this reference value and the detection value of the tension detecting means 18 can be set. By always properly controlling the rotation speed of the in-feed roller 7 based on the deviation from the above, there is an advantage that the fluctuation in the tension of the sheet material 1 can be effectively suppressed.

In particular, as shown in the above embodiment, when the in-feed roller 7 is directly driven by the drive motor 17 composed of an AC servomotor directly connected to the in-feed roller 7, FIG. As shown in the figure, the power transmission loss can be reduced as compared with the related art in which the infeed roller 7 is rotationally driven via a power transmission mechanism 8 such as a timing belt mechanism. The rotation speed of the in-feed roller 7 is quickly and accurately controlled in accordance with the control signal, so that the tension variation of the sheet material 1 can be effectively suppressed.

As shown in FIG. 3, the printing plate cylinder 4 is directly driven by a plate cylinder drive motor 25 composed of an AC servomotor directly connected to the printing plate cylinder 4 provided in each of the printing units 5a to 5n. In the case of driving, FIG.
As shown in FIG. 5, a main motor 27 for collectively driving the printing plate cylinders 4 arranged in the printing units 5a to 5n, and a power transmission mechanism 28 for transmitting the driving force to each printing plate cylinder are provided. As in a general printing press, the power transmission mechanism 28
Since there is no variation in the tension of the sheet material 1 caused by the operating resistance or the like, there is an advantage that the occurrence of misregistration caused by the variation in the tension can be effectively prevented.

Further, as shown in the above embodiment, by disposing the tension detecting means 18 on the downstream side of the dancer mechanism 10, the tension detecting means 1 is provided near the printing unit 5a.
In the case where the sheet material 8 is installed, the application position of the ink applied to the sheet material 1 can be appropriately adjusted by controlling the transport tension of the sheet material 1 in the introduction section to the printing unit 5a to an appropriate value. There are advantages.

In the above embodiment, an example is described in which the sheet tension control device according to the present invention is applied to a printing press having a plurality of printing units 5a to 5n, but the present invention is not limited to this. The present invention is also applicable to a laminating machine or an applicator for applying a coating material to a sheet material.

In the above embodiment, the discriminating unit 22
Regardless of whether or not it is determined that the displacement of the dancer roller 12 has occurred, the reference value of the transport tension stored in the reference value storage unit 23 and the transport of the sheet material 1 detected by the tension detecting unit 18 are performed. The rotation speed control of the infeed roller 7 corresponding to the deviation from the current value of the tension is performed. However, when the determination unit 22 determines that the dancer roller 12 is displaced, the deviation is determined. The corresponding speed control may be stopped, and only the rotation speed control based on the displacement of the dancer roller 12 may be executed.

[0043]

As described above, according to the present invention, an infeed roller which is rotated by a drive motor to convey a sheet material and a dancer roller provided in a sheet material conveying path are biased to urge the sheet material. A dancer mechanism that absorbs the slack of the sheet material and suppresses the elongation of the sheet material, a roller position detecting means for detecting a displacement of the dancer roller, a tension detecting means for detecting a conveying tension of the sheet material, and the roller position detection When it is confirmed that the dancer roller has been displaced from the reference position according to the detection signal of the means, the rotation speed of the infeed roller is controlled so that the dancer roller returns to the reference position, and the tension detection means detects If it is confirmed that a change in the tension of the sheet material has occurred in response to the signal, the infeed drawer is controlled to suppress the change in the tension. Rotation speed control means for controlling the rotation speed of the infeed roller at least in the dead zone where the dancer roller is held at the reference position in accordance with the detection signal of the tension detection means. With such a configuration, there is an advantage that both a minute tension fluctuation and a large tension fluctuation of the sheet material can be effectively suppressed, and the occurrence of print registration deviation can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a sheet material tension control device according to the present invention.

FIG. 2 is a block diagram showing a specific configuration of a rotation speed control unit.

FIG. 3 is an explanatory diagram illustrating an overall configuration of a printing press.

FIG. 4 is an explanatory view showing a conventional example of a sheet material tension control device.

FIG. 5 is an explanatory diagram showing a conventional example of a printing press.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sheet material 3 drawer 7 infeed roller 10 dancer mechanism 12 dancer roller 16 roller position detecting means 17 drive motor 18 tension detecting means 19 rotation speed control means 23 reference value storage section 24 control value setting section 25 plate cylinder drive motor

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Yoshitaka Nishihara, Inventor 2-7-1, Hachihonmatsu Iida, Higashihiroshima City, Hiroshima Prefecture Inside the Fujimoto Kogyo Co., Ltd. Yahonmatsu Plant (72) Inventor Yukio Ino Hachimotomatsu Iida, Higashihiroshima City, Hiroshima Prefecture 2-7-1, Fuji Machine Industry Co., Ltd. Yamotomatsu Plant (72) Inventor Katsuyuki Misawa 4010-14 Wada Minaminishihara, Matsumoto City, Nagano Prefecture Eiko Sokki Co., Ltd. Matsumoto Rinku Plant F term (reference) 2C034 AB11 AD03 AD06 AD11 AD12 AD15 AD17 2C250 EA04 EA06 EA33 EA34 EB03 EB50 3F105 AA02 AB03 BA01 BA07 CB03 CC02 DA04 DA09 DA13 DC02 DC03

Claims (4)

[Claims] 1. An infeed roller, which is rotated by a drive motor to convey a sheet material, and a dancer roller provided in a sheet material conveyance path is urged to absorb the slack of the sheet material and expand the sheet material. A dancer mechanism, a roller position detecting means for detecting a displacement of the dancer roller, a tension detecting means for detecting a conveying tension of the sheet material, and a dancer roller in accordance with a detection signal of the roller position detecting means. When it is confirmed that the dancer roller has been displaced from the reference position, the rotation speed of the infeed roller is controlled so as to return the dancer roller to the reference position, and the tension fluctuation of the sheet material is changed in accordance with the detection signal of the tension detecting means. If it is confirmed that a rotation has occurred, a rotation speed control that controls the rotation speed of the infeed roller to suppress this tension fluctuation Control means for controlling the rotation speed of the infeed roller in accordance with the detection signal of the tension detecting means in at least the dead zone where the dancer roller is held at the reference position. Sheet material tension control device. 2. The sheet tension control device according to claim 1, wherein the rotation speed control means determines that no displacement has occurred in the dancer roller according to a detection signal of the roller position detection means. A reference value storage unit for storing the detected value of the tension detecting means as a reference value of the conveying tension, and a reference value of the conveying tension stored in the reference value storing unit and the conveyance of the sheet material detected by the tension detecting means. A control value setting unit for setting a control value of a rotation speed of the in-feed roller corresponding to a deviation from the tension. 3. The sheet material tension control device according to claim 1, wherein the A is directly connected to the in-feed roller.
A sheet material tension control device comprising a drive motor comprising a C servomotor. 4. A printing press, comprising: a drawer provided with the sheet material tension control device according to claim 3; and a printing plate cylinder for applying ink to the sheet material supplied from the drawer. A printing press comprising a plate cylinder drive motor comprising an AC servomotor directly connected to the cylinder.