Ink quantity control system of web press

Abstract

The utility model discloses an ink quantity control system of a web press. The ink quantity control system comprises a main control unit, a network bridge and a motor driving unit, the main control unit comprises a PLC, a man-machine interaction assembly and a gateway communication interface. The network bridge comprises a gateway module, a network isolation module, a gateway communication interface and a CAN communication interface. The network bridge is connected with a gateway communication interface on the main control unit through a gateway bus; the motor driving unit comprises a plurality of motor driving plates; each motor driving board comprises four sets of motor driving circuits, a CAN communication interface and four motor control interfaces; outgoing lines of the four sets of motor driving circuits are connected with the four motor control interfaces in a one-to-one correspondence manner; the CAN communication interface on each motor driving board is connected with the CAN communication interface on the network bridge through a CAN bus; the four motor control interfaces on each motor driving board are connected with the four ink key motors in a one-to-one correspondence mode. According to the utility model, the ink feeding amount of any area can be accurately adjusted.

Description

Technical Field

[0001] This utility model relates to an ink volume control system for a roll paper printing machine. Background Technology

[0002] Printing presses require flexible and precise adjustment of ink volume according to the printing area during the printing process. The thickness of the ink layer is influenced not only by the properties of the ink and paper, but also by printing speed, printing pressure, and environmental factors (for example, different inks, due to their inherent differences in performance and tinting strength, require different ink layer thicknesses to achieve a specific density value). In short, in actual production, the ink volume control is highly uncertain and non-linear due to the influence of various factors such as the printing press model, paper, ink characteristics, ink-water balance, printing pressure, and measuring instruments. During operation, the required ink volume varies within the width of the printed material, which is achieved by adjusting the gap between the ink knife and the ink fountain roller. Existing ink knives are made of a single continuous steel sheet, and the ink volume is controlled by the height of a push rod. However, when adjusting the gap of the ink scalpel at a certain position, the continuity and elasticity of the steel sheet can interfere with the ink output at adjacent positions, resulting in unclear ink zone boundaries. Furthermore, over time, the steel sheet can fatigue and become wavy, making it impossible to accurately control the gap size and thus affecting print quality. This poses a problem for applications requiring precise ink volume control. Existing ink volume control systems in web printing presses have the following shortcomings:

[0003] 1. Analog potentiometers have a high failure rate and low accuracy, and require a large number of wiring harnesses, making them cumbersome and difficult to maintain.

[0004] 2. Full circuit board control systems are limited by high development and manufacturing costs and low compatibility. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an ink volume control system for a web printing press. This system can ensure precise control of ink volume and enable multi-segment ink knives and ink rollers to form a more uniform ink supply space.

[0006] The purpose of this utility model is achieved as follows: an ink volume control system for a web-fed printing press, used to control the ink knife installed in the ink fountain and the ink fountain roller to form a uniform ink supply space; the ink fountain includes two ink fountain end plates, an ink fountain seat, an ink knife, and multiple sets of ink volume adjustment mechanisms; the outer sides of the two ink fountain end plates are respectively installed on the inner sides of the two main wall plates of the printing press through ink fountain end shafts; the ink fountain seat spans between the two ink fountain end plates, the top surface of the ink fountain seat is a downward sloping surface, a rectangular upper notch is opened at the front end of the top surface of the ink fountain seat, and a rectangular lower notch is opened at the rear end of the bottom surface of the ink fountain seat; the ink knife is installed on the top surface of the ink fountain seat, and the ink knife is divided into multiple areas by multiple transverse cutting lines from a single ink knife; multiple sets of ink volume adjustment mechanisms are installed on the ink fountain seat in a corresponding manner to the multiple areas of ink knife;

[0007] Each ink volume adjustment mechanism includes a top block hinge shaft, an ink knife top block, an ink key motor, and a top rod; among which...

[0008] The top block hinge shaft spans between the two ink fountain end plates and is located above the upper notch of the ink fountain seat;

[0009] A hinge hole is provided on the upper side of the ink knife top block, so that the ink knife top block can be rotatably fitted onto the top block hinge shaft.

[0010] The ink key motor is mounted in the lower notch of the ink fountain holder via a motor mounting bracket; the ink key motor includes a brushless DC motor, a reducer connected to the front end of the shaft of the brushless DC motor, and a Hall encoder mounted at the rear end of the shaft of the brushless DC motor.

[0011] The push rod is connected to the rotating shaft of the ink key motor. The push rod is a screw and is installed in the threaded guide hole opened on the ink fountain seat. The front end of the push rod abuts against the lower rear end face of the ink knife top block, so that the top front end of the ink knife top block abuts against the bottom front end of the corresponding area ink knife.

[0012] The ink volume control system includes a main control unit, a PN_SWT bridge, and a motor drive unit;

[0013] The main control unit includes a PLC, a human-machine interface component, and a Profinet communication interface; the human-machine interface component includes a touch screen and a button panel.

[0014] The PN_SWT bridge includes a Profinet gateway module, a network isolation module, a Profinet communication interface, and a CAN communication interface; the PN_CAN bridge is connected to the Profinet communication interface on the main control unit via a Profinet bus.

[0015] The motor drive unit includes several motor drive boards; each motor drive board includes several sets of motor drive circuits, a CAN communication interface, and several motor control interfaces; the leads of the several sets of motor drive circuits are connected one-to-one with the several motor control interfaces; the CAN communication interface on each motor drive board is connected to the CAN communication interface on the PN_CAN bridge via a CAN bus; the several motor control interfaces on each motor drive board are connected one-to-one with several ink key motors.

[0016] The ink volume control system of the aforementioned web-based printing press includes two motor power lines, one Hall encoder power line, one Hall encoder ground line, and two signal lines for the Hall encoder power lines as the lead wires for each ink key motor; the motor control interface on the motor drive board is a six-pin socket.

[0017] The ink volume control system of the web-based printing press of this utility model has the following characteristics:

[0018] 1. Employing a micro motor driver board with Hall effect feedback, it boasts advantages such as small size, low power consumption, high integration, and high reliability. The motor driver board receives input signals from the PLC, processes them, and outputs them to the ink key motor, driving the ink scalpel to adjust its opening. Simultaneously, a Hall encoder monitors the ink scalpel position in real time, forming a closed-loop control to ensure precise ink volume control. This allows for a more uniform ink supply space between the multi-segment ink scalpels and the ink roller, reducing unnecessary waste. The modular design can accommodate various sizes and quantities of ink scalpels.

[0019] 2. All motor drive boards are centrally controlled by the main PLC. As an important piece of equipment in industrial automation, the PLC has advantages such as flexible programming, high reliability, and strong expandability. In addition, the main control unit communicates with the host computer through a communication interface, enabling remote monitoring and fault diagnosis functions.

[0020] 3. Hall encoders have a robust structure, long service life, and can work stably in various harsh environments, ensuring the long-term stable operation of electrical control systems. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the ink fountain structure targeted by the ink volume control system of the web-fed printing press of this utility model.

[0022] Figure 2 yes Figure 1 AA direction view in the middle;

[0023] Figure 3 This is a schematic diagram of the ink volume control system of the web-fed printing press of this utility model.

[0024] Figure 4This is a network topology diagram of the ink volume control system of the web-fed printing press of this utility model;

[0025] Figure 5 This is a control flowchart of the ink volume control system for the web-based paper printing press of this utility model. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings.

[0027] Please see Figure 1 and Figure 2 The ink volume control system of the web printing press of this utility model is used to control the ink knife installed in the ink fountain and the ink fountain roller to form a uniform ink supply space; the ink fountain includes two ink fountain end plates 1, ink fountain seat 2, ink knife 3 and twenty-two sets of ink volume adjustment mechanisms.

[0028] Two ink fountain end plates 1 are installed one-to-one on the inner side of the two main wall plates (not shown in the figure) of the printing press. The outer side of each of the two ink fountain end plates 1 is connected to an ink fountain end shaft 12 through a locking device 11. The two ink fountain end shafts 12 are installed one-to-one on the two main wall plates of the printing press.

[0029] The ink fountain holder 2 is connected between two ink fountain end plates 1. The top surface of the ink fountain holder 2 is a downward sloping surface. A rectangular upper notch is opened at the front end of the top surface of the ink fountain holder 2, and a rectangular lower notch is opened at the rear end of the bottom surface of the ink fountain holder 2. An ink knife mounting groove is opened in the middle of the top surface of the ink fountain holder 2, and two screw holes penetrating the rear end wall of the ink knife mounting groove are opened on the rear end surface of the ink fountain holder 2.

[0030] The ink scalpel 3 is fixed to the top surface of an ink scalpel base plate 30. The ink scalpel base plate 31 is installed in the ink scalpel mounting groove of the ink fountain holder 2. A bottom thread blind hole is opened at the front bottom of the ink scalpel base plate 31, and two rear thread blind holes are opened on the rear end face of the ink scalpel base plate 31, corresponding one-to-one with the two screw holes on the ink fountain holder 2. Two ink scalpel adjusting screws 32 are installed in the two screw holes on the ink fountain holder 2 and then screwed into the two rear thread blind holes on the ink scalpel base plate 31, corresponding one-to-one. The ink fountain holder 2 has two holes corresponding to the ink scalpel base plate 31. The two bottom thread blind holes on the top plate correspond one-to-one with the waist-shaped mounting holes. Each of the two waist-shaped mounting holes is fitted with a fixing screw 33. The two fixing screws 33 are screwed into the two bottom thread blind holes on the ink knife base plate 31. By rotating the two ink knife adjusting screws 32, the distance between the front end of the ink knife 3 and the ink fountain roller 10 can be initially adjusted. After adjustment, the ink knife base plate 31 is fixed to the ink fountain seat 2 by fixing screws 33. The ink knife 3 is divided into twenty-two sections of ink knife 30 by multiple transverse cutting lines from a whole ink knife.

[0031] Twenty-two sets of ink volume adjustment mechanisms are installed on the ink fountain base 2, corresponding one-to-one with twenty-two sections of ink knives 30. Each ink volume adjustment mechanism includes a top block hinge shaft 4, an ink knife top block 5, an ink key motor 6, and a top rod 7. The top block hinge shaft 4 spans between the two ink fountain end plates 1 and is located above the upper notch of the ink fountain base 2. A hinge hole is opened on the upper side of the ink knife top block 5, allowing the ink knife top block 5 to be rotatably fitted onto the top block hinge shaft 4. The ink key motor 6 is connected to the motor mounting bracket 61 and two connecting blocks 6. 2. Installed in the lower notch of the ink fountain holder 2, the ink key motor 6 includes a DC brushless motor, a reducer connected to the front end of the DC brushless motor shaft, and a Hall encoder installed at the rear end of the DC brushless motor shaft; the push rod 7 is connected to the shaft of the ink key motor 6 through a coupling 70. The push rod 7 is a screw and is installed in a threaded guide hole opened on the ink fountain holder 2, and the front end of the push rod 7 abuts against the lower rear end face of the ink knife top block 5, so that the top front end of the ink knife top block 5 abuts against the bottom front end of the corresponding area ink knife 30.

[0032] When the ink key motor 6 rotates forward, it drives the push rod 7 to rotate, causing the push rod 7 to push the ink knife top block 5 to rotate around the top block hinge shaft 4. In this way, the ink knife top block 5 pushes the front end of the corresponding section of the ink knife 30 upward, minimizing the gap δ between the front end of the corresponding section of the ink knife 3A and the ink fountain roller 10, which means the ink output of the ink fountain is minimized. Conversely, when the ink key motor 6 rotates in reverse, the ink knife top block 5 rotates around the top block hinge shaft 4 by its own weight, increasing the gap δ between the front end of the corresponding section of the ink knife 3A and the ink fountain roller 10, which means the ink output of the ink fountain increases.

[0033] Please see again Figure 3 and Figure 4 The ink volume control system of the web paper printing machine of this utility model includes a main control unit 100, a PN_CAN bridge 200 and a motor drive unit;

[0034] The main control unit 100 includes a PLC, a human-machine interface component, and a Profinet communication interface; the human-machine interface component includes a touch screen and a button panel.

[0035] The PN_CAN bridge 200 includes a Profinet gateway module, a network isolation module, a Profinet communication interface, and a CAN communication interface; the PN_CAN bridge 200 is connected to the Profinet communication interface on the main control unit 100 via the Profinet bus.

[0036] The motor drive unit includes six motor drive boards 300, each model DRVDM_103.PCB, which includes a motor drive circuit, a CAN communication interface, and four motor control interfaces. The four sets of motor drive circuits are connected to the four motor control interfaces one-to-one. Each motor control interface is a six-pin socket. The CAN communication interface of each motor drive board is connected to the CAN communication interface on the PN_CAN bridge via a CAN bus. The four motor control interfaces on five motor drive boards 300 are connected to the leads of four ink-keyed motors 6 one-to-one. The two motor control interfaces on one additional motor drive board 300 are connected to the leads of two ink-keyed motors 6 one-to-one. The leads of each ink-keyed motor 6 include two motor power lines, one Hall encoder power line, one Hall encoder ground line, and two Hall encoder signal lines.

[0037] The main control unit 100 is used to convert the operator's key commands into digital quantities and transmit them to the motor drive board 300. At the same time, it displays the current status of the ink key motor 6 in real time based on the data fed back by the motor drive board 300 to determine whether a fault has occurred.

[0038] Since the motor drive board 300 uses the CAN communication protocol, while the main control unit 100 uses the standardized Profinet protocol commonly used in PLC printing auxiliary system software, the PN_CAN bridge 200 is used to realize the interoperability between the CAN protocol and the Profinet protocol. At the same time, the PN_CAN bridge 200 effectively isolates network segments through the network isolation module, which improves the reliability and security of the system.

[0039] The motor drive board 300 precisely drives the Mojian motor based on the control information received from the PLC, and simultaneously transmits the motor's status information to the PLC based on the current position signal of the Mojian motor 6. The protection circuit in the motor drive board 300 can prevent damage to the control equipment caused by faults such as overcurrent caused by the Mojian motor 6, and reduce unstable electrical interference and signal crosstalk.

[0040] The communication data between each motor driver board 300 and the PN_CAN bridge 200 includes: motor set position, motor actual position, alarm information, fault reset control, and motor locking control.

[0041] The six motor drive boards 300 first establish communication with the main control unit 100 through the PN_CAN bridge 200. When the PLC sends a control signal, the PN_CAN bridge 200 sends the received signal to the motor drive board 300 through the CAN bus. The motor drive board 300 receives the signal sent by the PLC, processes it, and outputs it to the ink key motor 6 to drive the corresponding area ink knife 30 to adjust the opening. At the same time, the status information of the corresponding ink key motor 6 is monitored in real time through the Hall encoder and fed back to the motor drive board 300. When the motor drive board 300 sends the status information of the ink key motor 6 to the PN_CAN bridge 200, the PN_CAN bridge 200 automatically sends the data to the PLC through the Profinet communication interface, forming a closed-loop control.

[0042] The PLC adaptively calculates the target position of the keyed motor 6 by using the set position value and the current actual position value of the motor. Then, based on the target position of the keyed motor 6, the PLC drives the keyed motor 6 under the motor drive board 300. For ease of control and operation, four keyed motors 6 are grouped into one unit. The four keyed motors 6 can be freely combined and controlled by one motor drive board 300.

[0043] The CAN communication protocol used by the motor drive board 300 is converted by the PN_CAN bridge 200 to the Profine communication protocol used by the main control unit 100.

[0044] Please see again Figure 5 The ink volume control system of the web-fed printing press of this utility model is controlled according to the following steps:

[0045] S1. After powering on, the ink volume control system initializes. After initialization, it communicates and confirms with all motor drive boards. After successful communication handshake, the ink volume control system runs.

[0046] S2. Determine if the key motor is faulty. If it is faulty, control the key motor to stop rotating and wait for the fault to be cleared.

[0047] S3. After confirming that the key motor is fault-free, allow the key motor to rotate; check if the key motor is locked. If it is locked, it cannot be operated.

[0048] S4. If the key motor is fault-free and not locked, determine the position of the key motor. If the actual position of the key motor is equal to the set position of the key motor, then the key motor stops running.

[0049] S5. If the actual position of the key motor is less than the set position of the key motor, the key motor rotates forward; if the actual position of the key motor is less than the set position of the key motor, the key motor rotates in reverse.

[0050] S6. After starting the ink key motor to rotate forward or in reverse, record the rotation time of the ink key motor; if the ink key motor rotates beyond the time limit and the actual position of the ink key motor fails to reach the set position of the ink key motor, the ink volume control system will trigger a stall alarm and return to step S2, and the ink key motor will stop rotating.

[0051] Since the ink blade 3 of the roll offset printing machine is composed of twenty-two area ink blades 30, each area ink blade 30 is equipped with an independent ink volume adjustment mechanism. Each motor drive board 300 controls four area ink blades 30. The four area ink blades 30 can be freely combined, and then the ink volume of the four area ink blades can be finely adjusted through the above control method.

[0052] The above embodiments are for illustrative purposes only and are not intended to limit the present invention. Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also fall within the scope of the present invention and should be defined by the claims.

Claims

1. An ink volume control system for a web-fed printing press, used to control the ink knife installed in the ink fountain and the ink fountain roller to form a uniform ink supply space; the ink fountain includes two ink fountain end plates, an ink fountain seat, an ink knife, and multiple sets of ink volume adjustment mechanisms; the outer surfaces of the two ink fountain end plates are respectively installed on the inner sides of two main wall plates of the printing press through ink fountain end shafts; the ink fountain seat spans between the two ink fountain end plates, the top surface of the ink fountain seat is a downward sloping surface, a rectangular upper notch is opened at the front end of the top surface of the ink fountain seat, and a rectangular lower notch is opened at the rear end of the bottom surface of the ink fountain seat; the ink knife is installed on the top surface of the ink fountain seat, and the ink knife is divided into multiple areas by multiple transverse cutting lines from a single ink knife; multiple sets of ink volume adjustment mechanisms are installed on the ink fountain seat corresponding to the multiple areas of ink knife; wherein, Each ink volume adjustment mechanism includes a top block hinge shaft, an ink knife top block, an ink key motor, and a top rod; The top block hinge shaft spans between the two ink fountain end plates and is located above the upper notch of the ink fountain seat; A hinge hole is provided on the upper side of the ink knife top block, so that the ink knife top block can be rotatably fitted onto the top block hinge shaft. The ink key motor is mounted in the lower notch of the ink fountain holder via a motor mounting bracket; the ink key motor includes a brushless DC motor, a reducer connected to the front end of the shaft of the brushless DC motor, and a Hall encoder mounted at the rear end of the shaft of the brushless DC motor. The push rod is connected to the rotating shaft of the ink key motor. The push rod is a screw and is installed in the threaded guide hole opened on the ink fountain seat. The front end of the push rod abuts against the lower rear end face of the ink knife top block, so that the top front end of the ink knife top block abuts against the bottom front end of the corresponding area ink knife. The ink volume control system is characterized by comprising a main control unit, a PN_SWT bridge, and a motor drive unit. The main control unit includes a PLC, a human-machine interface component, and a Profinet communication interface; the human-machine interface component includes a touch screen and a button panel. The PN_SWT bridge includes a Profinet gateway module, a network isolation module, a Profinet communication interface, and a CAN communication interface; the PN_CAN bridge is connected to the Profinet communication interface on the main control unit via a Profinet bus. The motor drive unit includes several motor drive boards; each motor drive board includes several sets of motor drive circuits, a CAN communication interface, and several motor control interfaces; the leads of the several sets of motor drive circuits are connected one-to-one with the several motor control interfaces; the CAN communication interface on each motor drive board is connected to the CAN communication interface on the PN_CAN bridge via a CAN bus; the several motor control interfaces on each motor drive board are connected one-to-one with several ink key motors.

2. The ink volume control system for a web-fed printing press according to claim 1, characterized in that, Each ink key motor's lead wires include two motor power lines, one Hall encoder power line, one Hall encoder ground line, and two signal lines for the Hall encoder power lines; the motor control interface on the motor drive board is a six-pin socket.

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