Overprinting feeding mechanism of printing machine

Abstract

The utility model discloses an overprinting feeding mechanism of a printing machine, which comprises an unwinding traction roller group (2) and a photoelectric eye (8) arranged on a printing unit (7), and is characterized in that a variable speed adjusting traction roller group (6) is arranged between the unwinding traction roller group (2) and the printing unit (7); the photoelectric eye (8) can control the traction speed of the variable-speed adjusting traction roller set (6) to change according to the detected color code deviation condition, a tension roller (5) is arranged between the unwinding traction roller set (2) and the variable-speed adjusting traction roller set (6) and arranged on a movable seat (4), the movable seat (4) is connected with a tension limiting assembly, and the tension limiting assembly is connected with the tension limiting assembly. And the tension of the part, conveyed between the unwinding traction roller set (2) and the variable-speed adjusting traction roller set (6), of the printing base material is kept unchanged. The color code alignment device is simple in structure and reasonable in design, color code alignment printing during secondary printing can be achieved, it is guaranteed that tension of a printing base material is stable before the printing base material is fed into a printing unit, and printing accuracy and stability are effectively guaranteed.

Description

Technical Field

[0001] The utility model relates to printing equipment, in particular to an overprint feeding mechanism of a printing press. Background Art

[0002] A printing press is a common paper processing device, and its main function is to print ink on paper to form a required color pattern. According to different requirements, it may be necessary to perform secondary printing on the substrate. When performing secondary printing, it is necessary to ensure that the position of the second printing corresponds to the pattern of the first printing. Traditional printing presses use a photoelectric eye to detect the color mark after the first printing. If the color mark deviates, the rotation speed of the motor driving the plate cylinder is controlled to change, and then the angle of the plate cylinder is adjusted so that the subsequent printing position can adapt to the color mark deviation detected by the photoelectric eye, ensuring the accuracy of the secondary overprint position. The defect of the above structure is that the adjustment of the plate cylinder angle is limited, generally only adjustable within the space where there is no printing plate on the plate cylinder, and it is difficult to achieve precise adjustment for a large color mark deviation. Content of the Utility Model

[0003] In view of the deficiencies of the background art, the technical problem to be solved by the utility model is to provide an overprint feeding mechanism of a printing press for solving the above problems.

[0004] To this end, the utility model is implemented as follows:

[0005] The overprint feeding mechanism of a printing press includes an unwinding and traction roller group and a photoelectric eye arranged in a printing unit. It is characterized in that a variable-speed adjustment traction roller group is arranged between the unwinding and traction roller group and the printing unit. The photoelectric eye can control the change of the traction speed of the variable-speed adjustment traction roller group according to the detected color mark deviation. A tension roller is arranged between the unwinding and traction roller group and the variable-speed adjustment traction roller group. The tension roller is arranged on a moving seat, and the moving seat is connected with a tension limiting component, so that the tension of the part of the printing substrate conveyed between the unwinding and traction roller group and the variable-speed adjustment traction roller group remains unchanged.

[0006] An intermediate traction roller group is arranged between the unwinding and traction roller group and the tension roller. The traction speed of the intermediate traction roller group is consistent with that of the unwinding and traction roller group. The tension roller makes the tension of the part of the printing substrate conveyed between the intermediate traction roller group and the variable-speed adjustment traction roller group remain unchanged.

[0007] The tension limiting component includes a cylinder. The piston rod of the cylinder is connected with the moving seat. During operation, the air supply pressure and air supply direction of the cylinder remain unchanged.

[0008] Limit sensors are provided at both ends of the movement path corresponding to the moving seat. When any limit sensor detects the moving seat, the limit sensor will control the rotation speed of the unwinding and traction roller group to change the feeding speed and prevent the moving seat from continuing to move in that direction.

[0009] In the overprint feeding mechanism of the printing press with the above technical solution, by setting the variable-speed adjustment traction roller group, when the photoelectric eye detects that the color mark is offset, the rotation speed of the variable-speed adjustment traction roller group can be controlled to change, so as to realize the change of the traction amount of the subsequent printing substrate, ensure that the subsequent conveyed printing substrate can be accurately sent to the printing unit for printing, thereby improving the accuracy of overprinting and ensuring the overprint quality; at the same time, the structure of the tension roller and the tension limiting component is used in cooperation to ensure that when the rotation speed of the variable-speed adjustment traction roller group changes, the paper tension between the unwinding and traction roller group and the variable-speed adjustment traction roller group can remain unchanged, thereby avoiding the paper from being wrinkled or over-stretched and ensuring the stability of paper traction and conveying. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present utility model has the following drawings:

[0011] Figure 1 is the plane structure diagram of the present utility model;

[0012] Figure 2 is the plane structure diagram at the moving seat of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] As shown in the figure, the overprint feeding mechanism of the printing machine disclosed by the present utility model includes an unwinding and traction roller group 2 and a photoelectric eye 8 provided in the printing unit 7. A variable-speed adjustment traction roller group 6 is provided between the unwinding and traction roller group 2 and the printing unit 7. The photoelectric eye 8 can control the change of the traction speed of the variable-speed adjustment traction roller group 6 according to the detected color mark deviation. A tension roller 5 is provided between the unwinding and traction roller group 2 and the variable-speed adjustment traction roller group 6. The tension roller 5 is arranged on a moving seat 4, and the moving seat 4 is connected to a tension limiting component, so that the tension of the printing substrate during the transmission between the unwinding and traction roller group 2 and the variable-speed adjustment traction roller group 6 remains unchanged. Further, an intermediate traction roller group 3 is provided between the unwinding and traction roller group 2 and the tension roller 5. The traction speed of the intermediate traction roller group 3 is consistent with that of the unwinding and traction roller group 2. The tension roller 5 makes the tension of the printing substrate during the transmission between the intermediate traction roller group 3 and the variable-speed adjustment traction roller group 6 remain unchanged. By setting such a structure, when the speed of the variable-speed adjustment traction roller group 6 changes, it will not affect the traction work of the unwinding and traction roller group 2 at all, further ensuring the stability of the traction in the section where the printing substrate is pulled from the unwinding seat 1 to the unwinding and traction roller group 2, and enabling some operations such as reverse bending, corona treatment, and dust removal before printing to be carried out stably. In this embodiment, the tension limiting component includes a cylinder 9. The piston rod of the cylinder 9 is connected to the moving seat 4. During operation, the air supply pressure and air supply direction of the cylinder 9 remain unchanged. A sliding seat 11 is connected to the moving seat 4, and a slide rail 12 cooperating with the sliding seat 11 is provided on the frame to guide the movement of the moving seat 4. Of course, in addition to using a cylinder, a driving motor can also be provided, and the output end of the driving motor is connected to a screw rod. The screw rod is screwed to the moving seat. According to the information fed back by the photoelectric eye 8 to the controller, the controller will control the driving motor to drive the screw rod to rotate, thereby driving the moving seat 4 and the tension roller 4 to move to a suitable position, so as to ensure that after the rotational speed of the variable-speed adjustment traction roller group 6 changes, the tension of the printing substrate during the transmission between the intermediate traction roller group and the variable-speed adjustment traction roller group can still remain unchanged.Limit sensors 13 are provided at both ends of the moving path of the corresponding moving seat 4. When any limit sensor 13 detects the moving seat 4, the limit sensor 13 will control the rotation speed of the unwinding and traction roller group 2 to change, adjust the feeding speed, and prevent the moving seat 4 from continuing to move in this direction. By setting the limit sensors 13 to limit the moving path of the moving seat 4, it can be ensured that the moving seat 4 moves horizontally within a limited range, and prevent the moving seat 4 from colliding with other internal components during the movement. Specifically, when it is detected that the moving seat 4 moves to the limit sensor close to the intermediate traction roller group 3, this limit sensor feeds back information and controls the unwinding and traction roller group 2 and the intermediate traction roller group 3 to increase the traction speed, accelerate the conveying speed of the printing substrate, so that the moving seat 4 and the tension roller 5 will move away from the intermediate traction roller group 3. When it is detected that the moving seat 4 moves to the limit sensor far from the intermediate traction roller group 3, this limit sensor feeds back information and controls the unwinding and traction roller group 2 and the intermediate traction roller group 3 to slow down the traction speed, so that the conveying speed of the printing substrate becomes slower, and the moving seat 4 and the tension roller 5 will move towards the intermediate traction roller group 3.

[0014] The working principle of the present utility model is: The unwinding and traction roller group 2 drives the printing substrate to be unwound and traction from the unwinding seat 1, and then passes through the intermediate traction roller group 3, the tension roller 4, and the variable-speed adjustment traction roller group 6 in sequence, and then is sent into the printing unit 7. When the photoelectric eye 8 detects that the color marks of two overprints are offset, it will feed back information to the controller, and then the controller will control and change the traction speed of the variable-speed adjustment traction roller group 6 according to the offset amount and offset direction of the color mark, so that the pattern printed last time can be aligned with the position of the pattern printed the second time. Specifically, when it is detected that the color mark of the later printing is in front, the traction speed of the variable-speed adjustment traction roller group 6 is controlled to slow down. When it is detected that the color mark of the later printing is behind, the traction speed of the variable-speed adjustment traction roller group 6 is controlled to increase. When the traction speed of the variable-speed adjustment traction roller group 6 changes, due to the existence of the tension roller 5 and the tension limiting component, the moving seat 4 will drive the tension roller 5 to move under the action of the tension limiting component, so that the tension between the intermediate traction roller group 3 and the variable-speed adjustment traction roller group 6 remains unchanged, ensuring that the printing substrate in this interval will not wrinkle or be overstretched, ensuring the stability of the substrate conveying, and the rotation speed of the intermediate traction roller group always remains consistent with the rotation speed of the unwinding and traction roller group 2, which can ensure that the traction speed and tension of the printing substrate from the unwinding seat 1 to the unwinding and traction roller group 2 will not be affected by the change of the rotation speed of the subsequent variable-speed adjustment traction roller group 6, thereby improving the traction stability in the interval from the unwinding seat 1 to the unwinding and traction roller group 2.

[0015] With this structure of the present utility model, by setting a variable-speed adjusting traction roller group, after the photoelectric eye detects that the color mark is offset, the rotation speed of the variable-speed adjusting traction roller group can be controlled to change, thereby realizing the change of the traction amount of the subsequent printed substrate, ensuring that the subsequent conveyed printed substrate can be accurately sent to the printing unit for printing, thus improving the accuracy of overprinting and ensuring the overprinting quality; at the same time, the structure of the tension roller and the tension limiting component is used in cooperation to ensure that when the rotation speed of the variable-speed adjusting traction roller group changes, the paper tension between the unwind traction roller group and the variable-speed adjusting traction roller group can remain unchanged, thereby avoiding paper wrinkles or excessive stretching and ensuring the stability of paper traction and conveying.

Claims

1. The overprint feeding mechanism of a printing press, comprising an unwinding and traction roller set (2) and a photoelectric eye (8) provided in a printing unit (7), characterized in that: A variable-speed adjusting traction roller group (6) is arranged between the unwinding traction roller group (2) and the printing unit (7). The photoelectric eye (8) can control the change of the traction speed of the variable-speed adjusting traction roller group (6) according to the detected color mark offset. A tension roller (5) is arranged between the unwinding traction roller group (2) and the variable-speed adjusting traction roller group (6). The tension roller (5) is arranged on a moving seat (4), and the moving seat (4) is connected to a tension limiting component, so that the tension of the part of the printing substrate conveyed between the unwinding traction roller group (2) and the variable-speed adjusting traction roller group (6) remains unchanged.

2. The overprint feeding mechanism of the printing press according to claim 1, characterized in that An intermediate traction roller group (3) is arranged between the unwinding traction roller group (2) and the tension roller (5). The traction speed of the intermediate traction roller group (3) is consistent with that of the unwinding traction roller group (2). The tension roller (5) makes the tension of the part of the printing substrate conveyed between the intermediate traction roller group (3) and the variable-speed adjusting traction roller group (6) remain unchanged.

3. The overprint feeding mechanism of the printing press according to claim 1 or 2, characterized in that The tension limiting component includes a cylinder (9). The piston rod of the cylinder (9) is connected to the moving seat (4). During operation, the air supply pressure and air supply direction of the cylinder (9) remain unchanged.

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