Sheet-fed paper guiding mechanism

Abstract

The single-sheet paper correction mechanism is applied to the single-sheet paper die-cutting machine. The wallboard is one piece on each side, and is fixed into a frame by connecting crossbeams. First, the negative pressure belt is supported by the front guide roller, the middle guide roller, the rear guide rail and the negative pressure belt driving roller to form a circular running track. The belt driving motor is fixed under the negative pressure belt driving roller, and the negative pressure belt driving roller and the belt driving motor are connected by a synchronous belt through the negative pressure belt driving roller. The belt tensioning roller is connected to the tensioning adjustment device and fixed on the wallboard. The negative pressure chamber is placed under the negative pressure belt and fixed on the wallboard with screws. The negative pressure chamber is connected to the negative pressure fan through a pipeline. Behind the rear guide roller is a transition support plate, which is fixed on the wallboard. Behind the transition support plate is a correction execution device, and two transition plates are connected behind the execution device. This mechanism improves production efficiency and reduces production costs.

Description

Technical field:

[0001] This structure is applied to the range of sheet-fed die-cutting machines. Background technology:

[0002] At present, the sheet-fed die-cutting machines used by major domestic printing factories on the market are all flat-pressing equipment. The working principle of the fully automatic flat-pressing die-cutting machine is that the paper feeder feeds the paper into the front gauge and side gauge for positioning through the paper feeding component, and then the tooth bar sends the paper to the flat die-cutting mechanism for secondary positioning and die-cutting. After die-cutting, the tooth bar sends the paper to the waste removal mechanism, and then enters the paper collection department after waste removal, thus completing the die-cutting operation. This die-cutting machine has low efficiency due to the intermittent motion of the flat die-cutting action. The newly developed single-sheet die-cutting machine uses round-to-round die-cutting technology, and the die-cutting knife roller can die-cut continuously, thereby greatly improving the die-cutting efficiency. However, in this round-to-round die-cutting method, the tooth bar cannot be used to transfer the paper. The paper needs to be fed into the die-cutting machine through negative pressure or belt clamping. When the paper is transported forward without the tooth bar fixed, it will be skewed and lateral during the movement. Therefore, we invented a device for position correction of single paper during the transfer process under this situation. This device currently has no similar products at home and abroad, and it is the first case. Summary of the invention:

[0003] In order to improve production efficiency and reduce production costs, the present invention provides a deviation correction device applied to a single-sheet rotary die-cutting device.

[0004] We have designed and improved a correction mechanism based on servo / stepper motor as adjustment unit, photoelectric sensor as detection feedback unit, and negative pressure belt as front conveying unit. The negative pressure conveying unit is driven by a servo motor and produces negative pressure suction. During the conveying process, we will complete the position synchronization of the negative pressure conveying servo and the rear adjustment servo through PLC to reduce the friction between the back of the paper and the negative pressure belt during the lateral adjustment process. The adjustment unit consists of three small traction rollers driven by independent servos and a small pressure roller controlled by a small cylinder on it. The three servos are R side, M side, and L side servos. The detection feedback unit is mainly a photoelectric sensor (it can also be replaced by an ultrasonic sensor with a slightly lower accuracy). The system detects the area of ​​the paper edge blocking the sensor and the encoder position of the M servo feedback in the adjustment unit by the photoelectric sensor in the detection feedback unit, and calculates the paper deflection angle, and then converts the measured angle value into the pulse amount of the servo motor, and completes the correction adjustment by changing the position setting (speed change) of the servo motor on the R and L sides. Description of the drawings:

[0005] The following drawings and examples further illustrate the present invention:

[0006] Figure 1It is a front view schematic diagram of the present invention.

[0007] Figure 2 It is a top view schematic diagram of the present invention.

[0008] Figure 3 This is one of the operation diagrams.

[0009] Figure 4 This is the second operation diagram.

[0010] Figure 1 1. Front guide roller 2. Negative pressure belt 3. Negative pressure chamber 4. Middle guide roller 5. Negative pressure belt drive roller 6. Negative pressure belt tension roller 7. Tensioning adjustment device 8. Rear guide roller 9. Transition support plate 10. Cylinder support plate 11. Pressing cylinder 12. Glue pressure roller (L / M / R) 13. Photoelectric sensor 14. Sheet-fed printing product 15. Traction roller (L / M / R) 16. Synchronous belt for traction roller 17. Servo motor (L / M / R) 18. Wall panel 19. Synchronous belt for negative pressure belt drive roller 20. Belt drive motor 21. Fixed foot 22. Connecting beam Specific implementation method:

[0011] Figure 1In the embodiment, the wall panel 18 is composed of one piece on each side, which is fixed into a frame by a connecting crossbeam 22, and other components are installed in the frame. First, the negative pressure belt 2 is supported by the front guide roller 1, the middle guide roller 4, the rear guide rail 8 and the negative pressure belt driving roller 5 to form a circular running track. Each guide roller is fixed to the wall panel 18 through a bearing seat. The belt driving motor 20 is fixed below the negative pressure belt driving roller 5, and the negative pressure belt driving roller 5 and the belt driving motor 20 are connected by the synchronous belt 19 of the negative pressure belt driving roller, and the power of the motor is delivered to the negative pressure belt 2. The belt tensioning roller 6 is connected to the tensioning adjustment device 7 and fixed on the wall panel 18. The belt tensioning roller 6 adjusts the tightness of the negative pressure belt 2 through the tensioning adjustment device 7. The negative pressure chamber 3 is placed below the negative pressure belt 2 and fixed to the wallboard 18 with screws. The negative pressure chamber is connected to the negative pressure fan through a pipeline. The negative pressure fan forms negative pressure in the chamber, and then the single-sheet printed product 14 running on the belt is adsorbed through the small holes on the negative pressure belt. Behind the rear guide roller 8 is the transition support plate 9, which is fixed to the wallboard 18. Behind the transition support plate 9 is the deviation correction actuator, including the cylinder support plate 10, the pressing cylinder 11, the rubber pressure roller 12, the traction roller 15, the synchronous belt 16 for the traction roller and the servo motor 17. The traction roller 15 is fixed in the frame through the bearing seat, and the servo motor 17 is fixed below the traction roller 15. The traction roller synchronous belt 16 and the traction roller 15 are connected to transmit power. The rubber pressure roller 12 is installed above the traction roller 15, driven by the pressing cylinder 11, and pressed on the traction roller 15. The pressing cylinder 11 is fixed on the cylinder support plate 10, and the cylinder support plate 10 is fixed on the wall plate 18. Figure 2 As shown, this part of the actuator has 3 groups, named L side servo, M side servo and R side servo. Two transition support plates 9 are connected behind the actuator, and the photoelectric sensor 13 is installed in the middle of the two transition plates and fixed on the wall panel 18. There are 4 groups of fixed feet 21, which are respectively installed on the outside of both sides of the wall panel 18, and the entire deviation correction device is fixed to the ground through anchor bolts.

[0012] The sheet-fed printed product 14 is transferred from the upper device to the negative pressure belt 2. The negative pressure generated by the negative pressure chamber under the belt is used to fix the product on the negative pressure belt 2. The product moves along the negative pressure belt and enters between the rubber pressure roller 12 and the traction roller 15. Then, the product passes through the three sets of L / M / R correction execution devices and enters the photoelectric sensor 13. The system first determines the deflection direction of the paper by detecting the change in the area of ​​the paper edge blocking the sensor within a fixed time difference, that is, the sampling period, through the photoelectric sensor 13. After knowing the deflection direction, it is determined whether the servo motor on the L side or the R side adjusts the paper position. Secondly, we calculate the deflection angle of the paper through the area difference determined by the photoelectric sensor 13 within a sampling period. Finally, we use the spacing between the servo motors on the L side and the R side, the circumference of the traction roller, and the weekly pulse of the servo motor to calculate the number of pulses that the adjustment motor needs to take to speed up the forward speed of one side of the paper to make it flush with the other side, so as to achieve the effect of paper correction.

[0013] The specific operation principle is as follows:

[0014] The operation diagram is as follows Figure 3 and Figure 4

[0015] The meaning of each parameter code in the calculation:

[0016] Ts: Sampling period

[0017] H: Width of photoelectric sensor

[0018] S1: Photoelectric sensor shielding area 1

[0019] S2: Photoelectric sensor shielding area 2

[0020] L: Length of sheet-fed printed products (paper feed direction)

[0021] N: Maximum speed of die cutting machine

[0022] W: Distance between the L-side and R-side servo motors

[0023] A: Paper skew angle

[0024] Ps: The total number of pulses per rotation of the servo motor

[0025] Pm: The number of pulses required for the private service motor to perform the correction action

[0026] Cd: Circumference of traction roller

[0027] X: Single sheet skew lateral difference

[0028] Y: The distance that needs to be adjusted in the paper feeding direction of a single sheet of paper

[0029] Description of some parameter values:

[0030] Ts = 10 ms

[0031] Sampling period: The time when the PLC samples through timer interrupt or constant period. Considering the PLC operation ability, product specification size, and sampling frequency, 10 ms (millisecond) is taken as a reference value here.

[0032] L = 400 mm

[0033] The length of a single - sheet product determines the number of error detections and adjustments that can be completed at a certain running speed. Theoretically, the more the number of detections and adjustments, the higher the adjustment accuracy can be obtained. Conventionally, among the products we face, the length range of single - sheet paper is from 400 mm to 800 mm. We calculate with the smallest length which is the most difficult to adjust, so the value is taken as 400 mm. The number of adjustments is calculated as follows: The maximum running speed N of existing single - sheet die - cutting machines in the industry is 120 m / min. We multiply the N value by a safety factor of 1.25, and take the N value as 150 m / min for calculation. Substituting the L and N values into the formula, the time for the product to enter the sensor and leave the sensor is:

[0034]

[0035] Considering the influence of the installation position of the photoelectric sensor on the product length involved in the calculation, we take half of 160 ms, which is 80 ms, as the effective adjustment time. Since our sampling period Ts is 10 ms, that is, during the running of a 400 - mm product, we can complete 8 effective detections. According to the frequency of adjusting once every two detections, we can complete 4 effective adjustments (the position - loop gain set by the system determines the adjustment speed of the servo). Since the paper has been preliminarily positioned by the side - guide of the paper - feeding machine when it is sent out by the paper - feeding machine, the skew amount of the paper is not large. Therefore, 4 effective adjustments are sufficient to straighten the single - sheet paper.

[0036] Determination of the skew direction during product running:

[0037] As Figure 3 shown, after the single - sheet printed product 14 enters the photoelectric sensor 13 through the adjustment mechanism, the system obtains the real - time position data fed back by the M servo through 2 samplings. At the same time, we also obtain the AD (voltage signal 0 - 10 V) fed back by the system through the photoelectric sensor 13. As shown in the figure, we only need to compare the magnitudes of the S1 and S2 values collected by the system to know the skew direction of the paper. When S1 < S2, the paper skews to the right (taking the running direction as the reference). Conversely, the paper skews to the left.

[0038] Knowing the skew direction of the paper, we can determine which side of the servo motor is used to adjust the single - sheet printed product 14. In Figure 3Since the sheet-fed printed product 14 is tilted to the right, that is, the left side of the product is ahead of the right side, we need to increase the speed of the servo motor on the R side, and drive the R side traction roller 15 and the rubber pressure roller 12 to drive the right side of the sheet-fed printed product 14 forward quickly until it is flush with the left side, thus completing the deviation correction adjustment.

[0039] Correction action calculation principle

[0040] Since we use the same photoelectric sensor 13 to detect the skewness of the sheet-fed printed product 14, the skew angle of the sheet-fed printed product can be calculated by the formula using the area difference between S1 and S2 collected on both sides. The calculation formula is as follows:

[0041]

[0042] According to the calculated angle A value, the next step of calculation can obtain the distance X that the single-sheet printed product 14 needs to be offset on the R side, which is then converted into the number of pulses that the private servo motor needs to rotate, and the private servo motor is controlled by the controller to perform the correction operation.

[0043] The additional distance required to complete the deviation adjustment of the R side servo is

[0044] X=W*tan A

[0045] The number of pulses Pm that the servo needs to take is:

[0046] Pm=Y / Cd*Ps

[0047] At this point we have completed a complete skew detection and major correction actions.

Claims

1. A method for correcting the deviation of a single sheet of paper, characterized in that: The mechanism used in this method: The wall panels are one on each side, and are fixed into a frame by connecting crossbeams. First, the negative pressure belt is supported by the front guide roller, the middle guide roller, the rear guide roller and the negative pressure belt driving roller to form a circular running track. The belt drive motor is fixed below the negative pressure belt drive roller, and the negative pressure belt drive roller and the belt drive motor are connected by a synchronous belt through the negative pressure belt drive roller; the belt tensioning roller is connected to the tensioning adjustment device and fixed on the wall panel, the negative pressure chamber is placed below the negative pressure belt and fixed on the wall panel with screws, and the negative pressure chamber is connected to the negative pressure fan through a pipeline; Behind the rear guide roller is the transition support plate, which is fixed on the wall panel; behind the transition support plate is the deviation correction actuator, including the cylinder support plate, the clamping cylinder, the rubber pressure roller, the traction roller, the synchronous belt for the traction roller and the servo motor; the traction roller is fixed in the frame through the bearing seat, the servo motor is fixed under the traction roller, and the power is transmitted through the synchronous belt for the traction roller and the traction roller; the rubber pressure roller is installed above the traction roller, driven by the clamping cylinder and clamped on the traction roller; the clamping cylinder is fixed on the cylinder support plate, and the cylinder support plate is fixed on the wall panel; There are three groups of deviation correction actuators, named L-side servo, M-side servo and R-side servo respectively; two transition plates are connected behind the actuators, and the photoelectric sensor is installed in the middle of the two transition plates and fixed on the wall panel; the entire deviation correction mechanism is fixed to the ground by anchor bolts; The sheet-fed printed product is transferred to the negative pressure belt, and the negative pressure generated by the negative pressure chamber under the belt is used to fix the product on the negative pressure belt. The product moves along the negative pressure belt and enters between the rubber pressure roller and the traction roller. Then, the product passes through the three sets of L / M / R deviation correction actuators and enters the photoelectric sensor. First, the photoelectric sensor detects the change in the area of ​​the paper edge blocking the sensor within a fixed time difference, that is, the sampling period, to determine the skew direction of the paper. After knowing the skew direction, it is determined whether the servo motor on the L side or the R side adjusts the paper position. The skew angle of the paper is calculated through the area difference determined by the photoelectric sensor within a sampling period. Finally, the spacing between the servo motors on the L side and the R side, the circumference of the traction roller and the weekly pulse of the servo motor are used to calculate the number of pulses required to adjust the motor to speed up the forward speed of one side of the paper to make it flush with the other side, thereby achieving paper deviation correction.

2. The method for correcting the deviation of a single sheet of paper as claimed in claim 1, characterized in that: The meaning of each parameter code in the calculation: Ts: Sampling period H: Width of photoelectric sensor S1: Photoelectric sensor shielding area 1 S2: Photoelectric sensor shielding area 2 L: The length of a sheet-fed printed product, i.e. the paper feed direction N: Maximum speed of die cutting machine W: Distance between the L-side and R-side servo motors A: Paper skew angle Ps: The total number of pulses per rotation of the servo motor Pm: The number of pulses required for the private service motor to perform the correction action Cd: Circumference of traction roller X: Single sheet skew lateral difference Y: The distance that needs to be adjusted in the paper feeding direction of a single sheet of paper Description of some parameter values: Sampling period Ts = 10ms The length of a single paper product is L = 400mm The maximum operating speed N value of the single-sheet die-cutting machine is taken as 150 m / min for calculation; substituting the L and N values into the formula to calculate the time for the product to enter and leave the sensor: Determination of the skew direction during product operation: After the single-sheet printed product enters the photoelectric sensor through the adjustment mechanism, the system obtains the real-time position data of the M servo feedback through sub-sampling, and at the same time obtains the voltage signal AD feedback by the system through the photoelectric sensor; comparing the magnitudes of the S1 and S2 values collected by the system can tell the skew direction of the paper; when S1 < S2, the paper is skewed to the right based on the running direction; conversely, the paper is skewed to the left; The skew angle of the single-sheet printed product is calculated by the formula using the area difference of S1 and S2 collected on both sides. The calculation formula is as follows: Based on the calculated angle A value, through the next-step operation, the offset distance X that the single-sheet printed product needs to offset on the R side can be obtained, and then it is converted into the number of pulses that the servo motor needs to rotate more through calculation. The controller is used to control the servo motor to perform the deviation correction operation; The additional distance that the servo on the R side needs to travel to complete the deviation adjustment is X = W * tan A The number of additional pulses Pm that the servo needs to travel is: Pm = Y / Cd * Ps Complete a complete skew detection and main correction action.

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