An apparatus and method for reducing the impact of a printed sheet on a front gauge in a printing press

Abstract

The present invention discloses a device and method for reducing the impact of printing sheets on the front lay of a printing press, which relates to the technical field of printing equipment and aims to solve the problems in the prior art that the high-speed running of printing sheets impacts the front lay, causing structural damage and inaccurate positioning; the device includes a sheet transfer gripper table, a double-row vacuum flat belt, a sheet transfer gripper table seat, a front lay and an adaptive buffer assembly. The vacuum flat belt forms a negative pressure through an air chamber arranged on the sheet transfer gripper table to adsorb the printing sheet to achieve stable transportation; the adaptive buffer assembly is arranged between the double-row vacuum flat belts and adopts a friction buffer shaft structure with adsorption and damping functions to provide auxiliary buffering and deceleration when the printing sheet is a heavy material such as iron sheet; the device further includes a belt speed adjustment module controlled by servo drive to achieve the gradual control of the printing sheet speed from high speed to zero speed; the system of the present application has a high degree of integration and is particularly suitable for the precise control and protection of different types of printing sheets in high-speed and high-load printing environments.

Description

Technical Field

[0001] The present invention relates to the technical field of printing press sheet buffering, and specifically to a device and method for reducing the impact of sheets on the front guides of a printing press. Background Art

[0002] In order to ensure that the printed graphics are in exactly the same position on each sheet, the feeder head of the sheet feeder separates the stack of paper or iron sheets (hereinafter referred to as sheets) and feeds them at high speed onto the transfer platform of the printing press. First, the sheets need to be positioned in the paper feed direction (also known as the front-back direction) on the transfer platform so that they can enter the sheet-fed offset printing press for printing. The front-back positioning of the sheets is achieved by the front edge of the sheet contacting the front guides provided at the front end of the transfer platform.

[0003] The front-back positioning of the sheets at the front guides is carried out in a stationary zero-speed state. This requires the sheets to suddenly decelerate from the high-speed running state of the sheet feeder to zero speed and stop within a very short specified time. The high-speed running sheets will impact the front guides. Especially in the case of an iron printing press, due to the high density and greater weight of the iron sheets, the impact is even more severe, which can cause deformation and damage to the front guides, resulting in inaccurate front guide positioning, and a significant increase in the vibration and noise of the machine operation; the applicant's prior patent publication number CN201800314U discloses a front guide device for a printing press, which can prevent the paper from warping during operation and ensure the smooth positioning and transfer of the paper; the patent publication number CN118596700B has studied the side guides of a printing press and realized the positioning of iron sheets with notches, and can perform the positioning work for various specifications of paper and iron sheets with notches, but it cannot solve the impact of the sheets on the front guides.

[0004] In the existing printing press system, there is still a significant impact force when the sheets are positioned at the front guides, especially in the high-inertia scenario of iron sheets. To address this problem, some studies have focused on improving the motion characteristics and structural buffering performance of the front guide mechanism itself; for example, in the literature "Research on the Design Technology of the Front Guide and Cylinder of a High-Speed Iron Printing Press", through three-dimensional modeling and simulation, the dynamic analysis of the motion process of the front guide positioning mechanism is carried out, and the cam drive contour line is designed based on the optimal motion law; in addition, the printing pressure during the cylinder imprinting process is analyzed by combining the finite element simulation method. Although this solution improves the motion smoothness and positioning accuracy of the front guides, it still mainly relies on the optimization of the cam mechanism transmission path and is difficult to adapt to the impact load differences caused by changes in sheet quality. Especially in the case of iron sheets, there is a lack of a flexible mitigation mechanism for dynamic impacts; another example is the literature "Analysis and Research on the Swing-Type Buffer Front Guide of a Printing Press", which optimizes the parameters of the buffer action time and path; it improves the positioning performance at high speeds by optimizing the cam profile and buffer stroke. It does not have the ability to adapt to different sheet thicknesses and materials. Especially for high-quality media such as iron sheets, there are still impact errors and potential structural fatigue hazards.

[0005] In the prior art, there is a technology of using a cylinder buffer to impact the front gauge with the printed sheet. However, due to only using the cylinder buffer, the impact force of the high-speed printed sheet cannot be accurately controlled, and there is still a risk of deformation of the front gauge, resulting in low positioning accuracy. Although there is also a vacuum conveying system in the existing technology, it generally only realizes the conveying of materials. For example, the patent publication numbers CN218433133U, CN219193412U, and CN219193412U cannot be applied to the buffering and positioning of paper.

[0006] The patent publication number CN109986877A discloses an improved front gauge device for a printing press, and proposes an improved solution of using an electrostatic adsorption metal plate for printed sheet positioning. However, this solution is mainly applicable to paper and does not have a good adsorption effect on thick printed sheets such as iron sheets.

[0007] In summary, although there are various solutions in the prior art to improve the performance of the front gauge mechanism of the printing press, the problem of the impact of thick printed sheets, especially the impact of iron sheets on the front gauge in iron sheet printing, has not been solved. Therefore, a device and method for reducing the impact of the printed sheet on the front gauge of the printing press are proposed to solve the above problems. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the existing defects and provide a device and method for reducing the impact of the printed sheet on the front gauge of the printing press. Starting from the printed sheet conveying stage, this device coordinates and controls its speed, attitude, and positioning impact, and designs a new front gauge anti-impact and mitigation solution with dynamic deceleration, controllable adsorption, and adaptive buffering, which can effectively solve the problems in the background technology.

[0009] To achieve the above object, the present invention provides the following technical solutions: A device and method for reducing the impact of a printing sheet on a front gauge of a printing press, including a sheet transfer gripper table, a vacuum flat belt, a sheet transfer gripper table base, a front gauge, and an adaptive buffer assembly. The vacuum flat belt is arranged on the sheet transfer gripper table with an air chamber. The vacuum flat belts are symmetrically arranged on the sheet transfer gripper table to form a double-row vacuum conveyor belt. The air chamber forms a negative pressure to adsorb the printing sheet, so that the printing sheet moves with the double-row vacuum conveyor belt. At the same time, due to the action of the negative pressure, it can ensure that the printing sheet maintains a stable posture during the conveying process. A front gauge is arranged on the left side of the sheet transfer gripper table, and a sheet transfer gripper table base is arranged below the sheet transfer gripper table. The adaptive buffer assembly is arranged between the vacuum flat belts. The adaptive buffer assembly plays a role in supporting the printing sheet, and uses the self-weight of the printing sheet to adaptively achieve the effect of frictionally buffering the kinetic energy of the printing sheet. The adaptive buffer assembly includes an adaptive support frame, a mounting frame, a lifting frame, and friction buffer shafts. The friction buffer shafts are arranged on the adaptive support frame at equal intervals. The friction buffer shaft includes a hollow shaft, a rubber skin, and a damping shaft. The two ends of the hollow shaft are respectively connected to the adaptive support frame through the damping shafts. The damping shafts enable the hollow shaft to have a certain damping capacity. When the printing sheet passes through the hollow shaft, the speed of the printing sheet can be reduced due to the damping effect of the hollow shaft. When the printing sheet covers the double-row vacuum conveyor belt, the vacuum flat belt will adsorb the printing sheet, thereby restricting the printing sheet to move with the vacuum flat belt. When the printing sheet is made of iron sheet and has a heavier mass, the kinetic energy of the printing sheet is large, and it is difficult for the vacuum flat belt to adsorb the printing sheet. There is a risk that the printing sheet will shift and impact the front gauge. The hollow shaft with damping capacity can make up for the buffering capacity of the vacuum flat belt. Without increasing the volume of the mechanism, an adaptive frictional contact method is adopted to increase the contact force with the printing sheet, and cooperate with the double-row vacuum conveyor belt to play a role in quickly decelerating the printing sheet. The rubber skin is arranged on the outer surface of the hollow shaft along the circumferential direction, and there are long grooves between the rubber skins. The friction with the printing sheet is increased through the rubber skin. Equal-interval empty shaft air holes communicating with the inner cavity of the hollow shaft are arranged in the long grooves. Connecting pipes are respectively arranged on both sides of the adaptive support frame. The connecting pipes are communicated with the inner cavity of the hollow shaft. One end of the connecting pipe is connected to the interface pipe on the air chamber through an air pipe. The connecting pipes connect the hollow shafts in series, so that a negative pressure is generated inside the hollow shaft, and the moving printing sheet is sucked through the empty shaft air holes, further increasing the contact force with the printing sheet. This method can adapt to thick iron sheets or printing sheets with heavier weights and can play a good buffering role. The lifting frame is arranged above the mounting frame. A first spring is arranged between the lifting frame and the adaptive support frame. Through the first spring, the adaptive support frame has the ability to adaptively support the gravity of the printing sheet. The lifting frame can drive the adaptive support frame to hide in the sheet transfer gripper table base. When the printing sheet is paper, the double-row vacuum conveyor belt can meet the buffering of the printing sheet without the adaptive buffer assembly. When the printing sheet is an iron sheet or other printing sheets with heavier weights, the lifting frame drives the adaptive buffer assembly to rise and cooperate with the double-row vacuum conveyor belt to decelerate the printing sheet. And a damping structure is adopted, without additional energy consumption, and has the buffering ability applicable to all printing sheets while achieving energy saving.

[0010] Further, a guiding drum wheel assembly is provided on the sheet transfer gripper table seat. The guiding drum wheel assembly includes a flat belt drum wheel, an adjusting screw, and a guiding wheel shaft. The guiding wheel shaft is installed on the sheet transfer gripper table seat through the adjusting screw. The flat belt drum wheel is installed on the guiding wheel shaft through a first spherical bearing. The vacuum flat belt is wound around the flat belt drum wheel. By adjusting the inclination angle of the guiding wheel shaft, the position of the flat belt drum wheel is adjusted to achieve the positioning of the flat belt, thereby enabling the control of the attitude of the double-row vacuum flat belt on the sheet transfer gripper table seat, so that the sheet reaches the front guide in a stable vertical state. A flat belt supporting wheel is provided on the sheet transfer gripper table seat. The flat belt supporting wheel is located below the vacuum flat belt and serves to support the vacuum flat belt to ensure its stable operation.

[0011] Further, a flat belt driving wheel seat is provided on the right side of the sheet transfer gripper table seat. A flat belt driving group is provided on the flat belt driving wheel seat. The flat belt driving group includes a flat belt driving wheel shaft, a driving flat belt wheel, and a driven synchronous belt wheel. The driving flat belt wheel is installed on the flat belt driving wheel shaft through a first spherical bearing. One end of the flat belt driving wheel shaft is connected with the driven synchronous belt wheel through a common flat key. The vacuum flat belt is arranged between the flat belt drum wheel and the driving flat belt wheel. The driving flat belt wheel drives the vacuum flat belt to transmit between the flat belt drum wheel and the driving flat belt wheel. A servo driving module is provided on the sheet transfer gripper table seat. The servo driving module is used to drive the driving flat belt wheel to rotate. The servo driving module includes a synchronous belt, a flat belt driving wheel seat, a motor seat, a driving synchronous belt wheel, and a servo motor. The servo motor is installed on the flat belt driving wheel seat through the motor seat. The motor seat and the flat belt driving wheel seat are fixedly connected by screws. The flat belt driving wheel seat is fixedly connected with the sheet transfer gripper table seat. The driving synchronous belt wheel is installed on the output end of the servo motor through a common flat key. The synchronous belt is arranged between the driving synchronous belt wheel and the driven synchronous belt wheel. The servo motor provides power for the vacuum flat belt. The servo motor is controlled by the electrical control system through programming. Through the synchronous belt drive, the vacuum flat belt is driven to change from the speed of the vacuum flat belt transmission device of the sheet feeder to zero speed according to the designed compound motion law, so that when the sheet reaches the front guide initially, the speed is zero, realizing zero-speed positioning at the front guide, solving the impact of the sheet on the front guide, and realizing the precise positioning of the sheet at the front guide.

[0012] Further, a flat belt groove corresponding to the air chamber is provided on the upper surface of the sheet transfer gripper. The vacuum flat belt is located in the flat belt groove. Equally spaced flat belt air holes are provided on the surface of the vacuum flat belt. The upper plane of the vacuum flat belt is in the same plane as the upper plane of the sheet transfer gripper. The vacuum flat belt covers the air chamber of the sheet transfer gripper to form a negative pressure vacuum chamber. When the sheet covers the vacuum flat belt, the flat belt air holes on the vacuum flat belt will adsorb the sheet, thereby restricting the sheet to move along with the flat belt and reducing the speed of the sheet.

[0013] Further, the interface pipe of the air chamber is connected to a pneumatic control module through an air pipe. The pneumatic control module includes a solenoid valve, a vacuum regulating valve, and a pressure regulating valve. The solenoid valve is connected to the interface pipe of the air chamber through an air pipe. The solenoid valve is respectively connected to the vacuum regulating valve and the pressure regulating valve through air pipes. The vacuum regulating valve is connected to an external vacuum pump, and the pressure regulating valve is connected to an air compressor or a centralized gas supply system. The solenoid valve of the pneumatic control module performs air path conversion of suction and blowing according to the operating speed and rhythm of the printing press under the control of the PLC of the main electrical system of the printing press. The vacuum regulating valve precisely adjusts the vacuum value of the suction air path to adapt to different sheet changes. The pressure regulating valve precisely regulates the air path pressure of blowing to achieve precise air replenishment of the air chamber, so that the flat belt holes of the vacuum flat belt can release the sheet in time, enabling the sheet to leave the transfer gripper table at high speed after entering the printing press. The friction buffer shaft and the air chamber share a set of air paths, or a separate set of air paths can be set. When the sheet is made of iron sheet, the adaptive buffer assembly cooperates with the vacuum flat belt to complete the buffering of the sheet.

[0014] Further, a vacuum flat belt conveying device of the sheet feeder is arranged on the left side of the transfer gripper table. The sheet is conveyed on the vacuum flat belt conveying device of the sheet feeder, and the sheets are conveyed in a fish-scale stacking manner, that is, the latter sheet is stacked and conveyed under the previous sheet.

[0015] Further, a front gauge adjusting assembly is arranged on the left side of the mounting frame. The front gauge adjusting assembly includes a support shaft, an adjusting plate, a return force receiving plate, and a threaded rod. The support shafts are symmetrically arranged on both sides of the threaded rod. The adjusting plate is slidably connected to the support shaft. The front gauge is fixed on the inner side of the return force receiving plate. A guide shaft is arranged on the outer side of the return force receiving plate, and the guide shaft passes through to the outside of the adjusting plate. A second spring is sleeved on the guide shaft. When a fault occurs in the air path system, there is a risk that the sheet moving at high speed impacts the front gauge. The second spring plays a role in buffering external forces to prevent the sheet from impacting the front gauge, reducing the risk of damage to the front gauge and playing a protective role. A reset member is arranged between the adjusting plate and the return force receiving plate. The reset member can be a rebound device, a nitrogen cylinder, or a cylinder, as long as it can reset the return force receiving plate. Adjusting nuts are arranged on the threaded rod, and two adjusting nuts are provided. The position of the adjusting plate can be fixed through the adjusting nuts. If the adjusting nuts are loosened, the position of the adjusting plate can be adjusted to meet the usage requirements.

[0016] Further, fixing holes are respectively arranged on both side surfaces of the mounting frame, and bolts are inserted into the fixing holes. The mounting frame is fixed on the transfer gripper table seat through the bolts. A telescopic cylinder is arranged on the lower surface of the transfer gripper table seat. The telescopic end of the telescopic cylinder is connected to the lifting frame. Guide rods are arranged at the four corners of the lifting frame, and the guide rods pass through to the lower part of the mounting frame. The guide rods play a guiding role during the lifting process. The telescopic cylinder provides power for the lifting frame to drive the adaptive buffer assembly to rise or fall, so as to be able to adapt to the buffering of different sheets.

[0017] Furthermore, sealing grooves are respectively arranged on both end faces of the hollow shaft, and sealing rings are arranged in the sealing grooves to play a sealing role when connecting with the damping shaft. Threaded holes are also arranged on both end faces of the hollow shaft for fixing the hollow shaft. Retaining rings are respectively arranged at both ends of the hollow shaft, and the retaining rings are used to limit the installation position of the rubber skin and block both ends of the long groove at the same time to reduce air leakage.

[0018] Furthermore, a method for reducing the impact of a printed sheet on the front gauge of a printing press includes the following steps:

[0019] Step 1: The printed sheet is sent out by the feeder head of the sheet feeder in a fish-scale stacking manner, with the latter printed sheet located below the former one, and the former printed sheet enters the transfer gripper table area at a high speed.

[0020] Step 2: The printed sheet covers the double-row vacuum conveyor belt on the transfer gripper table; the flat belt air holes of the vacuum flat belt will adsorb the printed sheet, thereby restricting the printed sheet to move with the vacuum flat belt and guiding it to be conveyed along the direction of the front gauge.

[0021] Step 3: If the printed sheet is made of thick iron sheet material, before approaching the front gauge, the telescopic cylinder acts, and the adaptive buffer assembly rises, and the printed sheet contacts the adaptive buffer assembly arranged between the printed sheet and the vacuum flat belt; the hollow shaft is communicated with the air chamber through the air holes of the hollow shaft and forms additional adsorption, providing friction and additional adsorption force to passively decelerate and buffer the printed sheet.

[0022] Step 4: The vacuum flat belt is driven by a servo motor, and the servo control system controls its running speed to gradually decrease from a high speed to zero speed according to a set rule, so that the printed sheet contacts the front gauge at zero speed, completing precise positioning and eliminating impact.

[0023] Step 5: The front gauge is flexibly buffered and reset. When a slight impact occurs, the front gauge adjustment assembly buffers and absorbs energy to protect the front gauge from damage; and makes the front gauge automatically reset.

[0024] Step 6: After the zero-speed positioning is completed, the pneumatic control module issues an instruction, and the solenoid valve switches to the blowing state, and the vacuum adsorption is released; the printed sheet smoothly leaves the transfer gripper table area and enters the formal printing process.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. By setting the double-row vacuum conveyor belt and cooperating with the adaptive buffer assembly, active deceleration and dynamic attitude control of the printed sheet, especially thick printed sheets such as iron sheets, are realized before approaching the front gauge, effectively reducing the impact strength on the front gauge; significantly reducing front gauge wear and structural fatigue, and improving the equipment life and printing stability.

[0027] 2. The servo motor realizes the motion control of the double-column vacuum flat belt. Combined with the dynamic deceleration during the sheet feeding process, the sheet is automatically decelerated to zero speed before reaching the front guide, thus achieving zero-speed contact positioning and eliminating the errors of traditional positioning by relying on inertial impact. An adaptive buffer component with lifting and elastic support functions is set, which can select whether to enable the buffer structure according to the thickness and material of the sheet, such as paper or iron sheet, to ensure that the system has the optimal buffer mode under different working conditions. The buffer component does not require external energy consumption and can provide reliable support only through spring force and damping structure, which not only saves energy but also improves the universality of the system.

[0028] 3. The front guide structure introduces an adjustment component with elastic energy absorption and position fine-tuning functions. In the case of abnormal impact, it can temporarily buffer deformation and return to its original position after the impact, preventing the front guide from being permanently deformed or displaced, and improving the safety and maintainability of the whole machine.

[0029] 4. The whole structure adopts modular design. The double-column vacuum belt, adaptive buffer component, servo system and pneumatic control module cooperate closely, and the control logic is clear. Without adding large energy-consuming devices, fine control can be achieved only by using the original PLC and servo system, which has the comprehensive advantages of convenient installation, low energy consumption and fast response speed, and is suitable for long-term operation in high-speed and high-intensity printing environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic cross-sectional structure diagram of the sheet transfer gripper seat of the present invention;

[0031] Figure 2 It is an axonometric drawing of the sheet transfer gripper shaft of the present invention.

[0032] Figure 3 It is a schematic structure diagram of the present invention with a regulating valve and a motor;

[0033] Figure 4 It is a schematic top view structure diagram of the present invention;

[0034] Figure 5 It is an axonometric drawing of the adaptive buffer component of the present invention Figure 1 ;

[0035] Figure 6 It is a schematic top view structure diagram of the adaptive buffer component of the present invention;

[0036] Figure 7 It is a schematic left view structure diagram of the adaptive buffer component of the present invention;

[0037] Figure 8 It is a schematic structure diagram of the friction buffer shaft of the present invention;

[0038] Figure 9 It is an axonometric drawing of the adaptive buffer component of the present invention Figure 2 .

[0039] In the figure: 1 is the subsequent printing sheet, 2 is the previous printing sheet, 3 is the vacuum flat belt conveying device of the sheet feeder, 4 is the sheet transfer gripper table, 5 is the vacuum flat belt, 6 is the air chamber, 7 is the front gauge, 8 is the flat belt drum-shaped wheel, 9 is the sheet transfer gripper table seat, 10 is the interface pipe, 11 is the solenoid valve, 12 is the vacuum regulating valve, 13 is the pressure regulating valve, 14 is the flat belt support wheel, 15 is the flat belt tensioning wheel, 16 is the driven synchronous belt pulley, 17 is the synchronous belt, 18 is the flat belt driving pulley seat, 19 is the motor seat, 20 is the driving synchronous belt pulley, 21 is the servo motor, 22 is the driving flat belt pulley, 23 is the ordinary flat key, 24 is the flat belt driving pulley shaft, 25 is the first ball bearing, 26 is the second ball bearing, 27 is the flat belt tensioning wheel shaft, 28 is the adjusting screw, 29 is the guide wheel shaft, 30 is the front gauge adjusting assembly, 31 is the adaptive buffer assembly, 32 is the flat belt air hole, 33 is the support shaft, 34 is the adjusting plate, 35 is the return force receiving plate, 36 is the fixing hole, 37 is the friction buffer shaft, 38 is the adaptive support frame, 39 is the lifting frame, 40 is the first spring, 41 is the connecting pipe, 42 is the installation frame, 43 is the threaded rod, 44 is the damping shaft, 45 is the adjusting nut, 46 is the second spring, 47 is the guide shaft, 48 is the telescopic cylinder, 49 is the guide rod, 50 is the hollow shaft, 51 is the retaining ring, 52 is the rubber skin, 53 is the hollow shaft air hole, 54 is the long slot, 55 is the sealing slot, 56 is the flat belt slot. Specific implementation mode

[0040] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0041] Please refer to Figures 1-9, the present invention provides a technical solution: a device and method for reducing the impact of printing sheets on the front guides of a printing press, including a sheet transfer gripper table 4, a vacuum flat belt 5, a sheet transfer gripper table base 9, a front guide 7, and an adaptive buffer assembly 31; the vacuum flat belt 5 is arranged on the sheet transfer gripper table 4 with an air chamber 6, and is arranged symmetrically in a double row to form a double-row vacuum conveyor belt; the air chamber 6 provides negative pressure to make the vacuum flat belt 5 adsorb the printing sheet during operation to ensure its stable attitude transmission; a front guide 7 is provided on the left side of the sheet transfer gripper table 4, and a sheet transfer gripper table base 9 is configured below it. The adaptive buffer assembly 31 is arranged between the double-row vacuum conveyor belts and constitutes a buffer structure for the printing sheet; this assembly includes an adaptive support frame 38, a mounting frame 42, a lifting frame 39, and a friction buffer shaft 37. Among them, the friction buffer shaft 37 is composed of a hollow shaft 50, a rubber skin 52, and a damping shaft 44, and is arranged at equal intervals along the adaptive support frame 38; both ends of the hollow shaft 50 are connected to the support frame through the damping shaft 44 to form a buffer structure with a damping effect; the rubber skin 52 covers the outer surface of the hollow shaft 50, and is provided with a circumferential long groove 54, and an air hole 53 for the hollow shaft is arranged in the groove and communicates with the inner cavity of the hollow shaft 50; connecting pipes 41 are provided on both sides of the adaptive support frame 38 and are in gas path communication with the interface pipe 10 of the air chamber 6 to realize the negative pressure adsorption function; a first spring 40 is arranged between the lifting frame 39 and the mounting frame 42 to endow it with the ability of pressure-bearing buffering, and can store the adaptive support frame 38 inside the sheet transfer gripper table base 9 when buffering is not required.

[0042] In this embodiment, a double-row conveying structure is formed by the vacuum flat belt 5 on the sheet transfer gripper table 4, and negative pressure is supplied by the air chamber 6 to adsorb the printing sheet to ensure that the printing sheet moves forward at a high speed with a stable attitude; the adaptive buffer assembly 31 is arranged between the double-row flat belts to provide additional support and buffering when heavy printing sheets such as iron sheets pass through; the friction buffer shaft 37 realizes the energy release when contacting the printing sheet through the hollow shaft 50 and the damping shaft 44. Its rubber skin 52 and long groove 54 structure increase the friction contact area. At the same time, the negative pressure generated inside the hollow shaft 50 enhances the adhesion force through the air hole 53; under the action of high-inertia media such as iron sheets, this buffer mechanism effectively reduces the offset risk of insufficient adsorption of the vacuum flat belt 5, and cooperates with the vertical elastic deformation of the first spring 40 to absorb the impact, realizing active buffering in a limited space; the lifting frame 39 cooperates with the spring and the structural layout, and can hide the entire assembly back into the sheet transfer gripper table base 9 under working conditions where buffering is not required.

[0043] This embodiment significantly improves the operating stability and safety of the printing press when processing heavy printed sheets such as iron sheets; through the setting of the adaptive buffer component 31, the friction contact force between the printed sheets and the conveying mechanism is enhanced, effectively buffering the impact force of the printed sheets on the front gauge, and reducing the risk of fatigue and loss of the front gauge structure; the system does not need to rely on an additional drive device, and only uses the damping shaft 44 and the spring 40 to provide buffering, with the advantages of low energy consumption, simple maintenance, and rapid response; the double-row vacuum belt cooperates with the central buffer device to ensure that the printed sheets can achieve posture-controllable buffer deceleration even at high speeds, creating good conditions for subsequent zero-speed positioning.

[0044] In specific applications, the rubber skin 52 covering the hollow shaft 50 can be replaced with materials with different hardness or surface friction coefficients, such as nitrile rubber or polyurethane materials, to adapt to different paper types or surface characteristics; the stiffness and damping coefficient of the damping shaft 44 can be adjusted according to the weight level of the printed sheet, using metal springs or fluid dampers of different specifications; the length, spacing and diameter of the long groove 54 and the air hole 53 structure can be adjusted according to the required adsorption force; in terms of the lifting structure, in addition to the spring 40 and the lifting frame 39, a pneumatic lifting mechanism or an electric push rod can also be used as a substitute to adapt to a printing system with a higher degree of automation; the mounting frame 42 can also be modularly adjusted according to the installation space and layout limitations, while maintaining the overall functional integrity and improving the flexibility of system integration.

[0045] A guide drum wheel assembly is arranged on the paper delivery tooth seat 9, and the assembly includes a flat belt drum wheel 8, an adjusting screw 28 and a guide wheel shaft 29; the guide wheel shaft 29 is installed on the paper delivery tooth seat 9 through the adjusting screw 28, and the flat belt drum wheel 8 is installed on the guide wheel shaft 29 through a ball bearing 25, so that the flat belt drum wheel 8 can rotate; the vacuum flat belt 5 is wound around the flat belt drum wheel 8, and the inclination angle of the guide wheel shaft 29 can be adjusted to achieve fine adjustment of the position of the flat belt drum wheel 8, thereby adjusting the posture of the vacuum flat belt 5 on the paper delivery tooth seat 4; in order to further improve the stability of the flat belt operation, a flat belt support wheel 14 is also arranged on the paper delivery tooth seat 9, which is located below the vacuum flat belt 5 to form a reliable support for the vacuum flat belt 5.

[0046] The guide drum wheel assembly fixes the position of the guide wheel shaft 29 by adjusting the screw 28, controls the angle of the flat belt drum wheel 8, and then adjusts the tension and path of the vacuum flat belt 5 on the paper delivery tooth table 4; the vacuum flat belt 5 extends from the front paper feeding end to the direction of the front gauge 7, and is wound between the flat belt drum wheel 8 and the active flat belt wheel; by adjusting the position and angle of the drum wheel 8, it is ensured that the double-row vacuum flat belts are stable, parallel and moderately tensioned, so that the movement of the printed sheets on it is more stable and reliable; in addition, the flat belt support wheel 14 arranged below it provides a lifting effect to prevent the flat belt from sag or vibrate under the pressure of the printed sheets, maintain its straightness and stability in operation, further reduce the deviation and jump of the printed sheets due to the instability of the conveying channel, and improve the positioning accuracy of the front gauge.

[0047] By arranging an adjustable guide drum assembly on the sheet transfer gripper base 9, flexible control of the attitude of the vacuum flat belt is achieved, which helps to adapt to the conveying requirements of different specifications or different thicknesses of printing sheets and ensures good attitude control during high-speed conveying. The arranged flat belt support wheel 14 effectively supports the sagging or vibrating conveyor belt, making its long-term operation more stable, further enhancing the contact uniformity between the printing sheet and the conveyor belt, effectively improving the linearity of the running track of the printing sheet, and enhancing the accuracy of front registration and the reliability of equipment operation.

[0048] In practical applications, the guide wheel shaft 29 can adopt an eccentric sleeve connection method to achieve finer angle adjustment; the flat belt drum 8 can also be replaced with rollers of different curvature radii to adapt to vacuum flat belts 5 of different bandwidths or different flexibility degrees; the adjusting screw 28 can be replaced with a quick-release structure or a spring locking structure for quick disassembly and assembly during maintenance; the flat belt support wheel 14 can adopt a needle roller bearing or a magnetic levitation support structure to further reduce running friction and improve the system response speed; at the same time, the material of the support wheel can be selected as metal or high-strength composite material according to the application environment to meet the stable operation requirements under high load or high-temperature environments.

[0049] A flat belt driving wheel base 18 is arranged on the right side of the sheet transfer gripper base 9. A flat belt driving group is installed on the driving wheel base 18. The driving group includes a flat belt driving wheel shaft 24, a driving flat belt wheel 22, and a driven synchronous belt wheel 16. The driving flat belt wheel 22 is installed on the driving wheel shaft 24 through a ball bearing 1 25. One end of the driving wheel shaft 24 is connected with the driven synchronous belt wheel 16 through a common flat key 23. The vacuum flat belt 5 is spanned between the flat belt drum 8 and the driving flat belt wheel 22, and the vacuum flat belt 5 is driven to run through the driving flat belt wheel 22. A servo driving module is also installed on the sheet transfer gripper base 9. The module includes a synchronous belt 17, a flat belt driving wheel base 18, a motor base 19, a driving synchronous belt wheel 20, and a servo motor 21. The servo motor 21 is installed on the driving wheel base 18 through the motor base 19. The motor base 19 and the driving wheel base 18 are fixed by screws. The driving wheel base 18 and the sheet transfer gripper base 9 are an integral fixed structure. The driving synchronous belt wheel 20 is installed at the output end of the servo motor 21 through a common flat key 23. The synchronous belt 17 connects the driving synchronous belt wheel 20 and the driven synchronous belt wheel 16 to achieve power transmission. The servo motor 21 provides driving force for the vacuum flat belt 5 and its operation is programmed and controlled by an electrical control system to precisely control the motion law of the vacuum flat belt 5.

[0050] The servo motor 21 drives the rotation of the driving synchronous pulley 20, and the power is transmitted to the driven synchronous pulley 16 through the synchronous belt 17, further driving the driving flat pulley 22, and then driving the vacuum flat belt 5 to achieve a closed-loop operation between the drum-shaped wheel 8 and the driving flat pulley 22; under the programming control of the control system, the servo motor 21 can make the speed of the vacuum flat belt 5 gradually decelerate from the high speed at the paper feeding machine end to zero speed at the front gauge 7 according to the preset compound motion law, realizing the precise deceleration conveying of the printed sheet; this servo control method can achieve contact with zero speed when the printed sheet approaches the front gauge 7, thus effectively avoiding the positioning deviation and structural damage caused by traditional inertial impact.

[0051] This implementation method realizes high-precision control of the movement speed of the vacuum flat belt by introducing a servo drive system, ensuring that the printed sheet can achieve "zero-speed" contact when approaching the front gauge, and significantly improving the front and rear positioning accuracy of the printed sheet; compared with the traditional fixed-speed conveying method, using servo control can not only adapt to different requirements of the printed sheet material, thickness and weight, but also dynamically respond to the adjustment of the operation rhythm, improving the flexibility and stability of the whole machine operation; at the same time, the structures such as the motor base and the driving wheel base adopt standardized and modular design, which is convenient for maintenance and upgrading.

[0052] The servo drive system can be replaced by a stepping motor or a DC motor with a feedback encoder, and can be flexibly selected according to the actual accuracy and response requirements; the synchronous belt 17 can adopt a steel wire reinforced material to improve wear resistance and service life; if higher requirements for system compactness are required, gear transmission or a planetary reduction integrated servo mechanism can also be used; the motor base 19 can also be designed as an integral die-cast structure to improve rigidity and thermal stability; in special applications, the servo motor 21 can also achieve more advanced real-time data interaction and control strategies through the network bus with the main control PLC system.

[0053] The upper surface of the sheet transfer gripper table 4 is provided with a flat belt groove 56 corresponding to the air chamber 6, and the vacuum flat belt 5 is embedded in the flat belt groove 56, and its upper surface is kept in the same plane as the upper surface of the sheet transfer gripper table 4; the surface of the vacuum flat belt 5 is provided with evenly distributed flat belt air holes 32 along the conveying direction, and the whole vacuum flat belt 5 covers the air chamber 6 to form a continuous negative pressure vacuum air chamber structure; when the printed sheet passes through and covers the vacuum flat belt 5, the air holes 32 firmly adsorb the printed sheet on the conveying surface through negative pressure suction, realizing the constrained conveying of the printed sheet, and cooperating with the running direction of the conveyor belt, guiding the printed sheet to be conveyed smoothly towards the front gauge 7 until deceleration positioning is achieved.

[0054] The flat belt groove 56 provides a structural space for precise positioning and installation, ensuring the straightness and consistency of the vacuum flat belt 5 when arranged along the paper feeding tooth table 4, which is conducive to achieving stable control of the posture of the printed sheet; the flat belt air holes 32 arranged on the surface of the vacuum flat belt 5, through the negative pressure environment formed by the air chamber 6, start the adsorption effect when the printed sheet is covered; the adsorption force ensures that the printed sheet will not float, deflect, etc. during high-speed transportation, thereby achieving stable and efficient transportation; at the same time, the printed sheet and the flat belt form a fitting state due to the negative pressure, thereby reducing the possibility of their relative slippage, providing a good foundation for the subsequent deceleration control and the role of the buffer device.

[0055] This structural design realizes the efficient integration of the vacuum flat belt 5 and the paper delivery tooth table 4. The vacuum flat belt 5 is embedded in the flat belt groove 56 to improve its flatness and working stability. The flat belt air holes 32 arranged on the surface enhance the vacuum adsorption capacity, so that the printed sheets remain in a stable state during movement, and effectively avoid swinging, tilting and other phenomena caused by conveying vibration or wind disturbance, providing the prerequisite for accurate positioning and buffering. This method is particularly suitable for processing lightweight and easily warped printed sheets, and improves the conveying stability and working efficiency of the whole machine.

[0056] The groove depth and groove width of the flat belt groove 56 can be adjusted according to the thickness of the vacuum flat belt 5 to ensure close fitting and easy replacement; the size, spacing and arrangement of the flat belt air holes 32 can be customized according to the sheet size and adsorption area requirements, and common forms include staggered holes, linear arrangement, etc.; the vacuum flat belt 5 can also use a high-friction material with a microporous layer or a multi-layer composite structure to further improve the adsorption stability; under specific needs, the flat belt groove 56 can also be designed as a modular structure with adjustable depth to meet the convenience and diversity of replacement and maintenance of flat belts of different specifications.

[0057] The interface pipe 10 of the air chamber 6 is connected to the air control module through an air pipe, and the air control module includes a solenoid valve 11, a vacuum regulating valve 12 and a pressure regulating valve 13; the solenoid valve 11 is connected to the interface pipe 10 through an air pipe, and is respectively connected to the vacuum regulating valve 12 and the pressure regulating valve 13; the vacuum regulating valve 12 is connected to an external vacuum pump to achieve precise adjustment of the vacuum value of the suction air circuit; the pressure regulating valve 13 is connected to an air compressor or a centralized air supply system to achieve pressure adjustment of the blowing air circuit of the air chamber 6; the solenoid valve 11 is under the control of the PLC of the printing press main control system, and automatically switches the suction and blowing states according to the operating rhythm of the printing press; the flat belt air holes 32 of the vacuum flat belt 5 can absorb or release the printed sheets when needed; the friction buffer shaft 37 and the air chamber 6 can share the above-mentioned air circuit, or can be set independently to improve the system redundancy; when the printed sheet is a heavy medium such as iron sheet, the adaptive buffer component 31 links the vacuum flat belt 5 to complete coordinated buffering of the printed sheet.

[0058] In this embodiment, the electromagnetic valve 11 realizes the switching between the suction and blowing states under the control of the PLC. Cooperating with the negative pressure value set by the vacuum regulating valve 12, stable adsorption is achieved when the printed sheet passes through the vacuum flat belt 5, ensuring stable transportation. When the printed sheet is positioned at the front gauge 7, the electromagnetic valve 11 switches to the blowing state, and the pressure regulating valve 13 quickly supplies air to the air chamber 6 according to the set air pressure, releasing the vacuum adsorption and pushing the printed sheet to quickly leave the sheet transfer gripper table 4 area and enter the printing station, improving the overall production rhythm and efficiency. The friction buffer shaft 37 can also form an additional suction force on the printed sheet through the hollow shaft air hole 53 under the negative pressure state, further enhancing the buffering performance and contact stability.

[0059] By establishing a complete suction and exhaust control module, the system has fine control capabilities for adsorption and release, adapts to printed sheets of different weights and materials, and ensures their stability and efficiency under different working conditions. By controlling the adsorption rhythm with electromagnetic valves and cooperating with vacuum regulation and air pressure regulation, flexible control of the vacuum intensity and release speed is achieved, which is especially suitable for high-speed continuous printing scenarios. In addition, the system supports the common use of the air path by the friction buffer shaft and the main air chamber, and can also achieve independent control, improving the compatibility and redundancy of the system.

[0060] The electromagnetic valve 11 can select a proportional electromagnetic valve with a faster response speed to achieve more fine-grained air flow control. The vacuum regulating valve 12 and the pressure regulating valve 13 can also be upgraded to electronic precision pressure regulators for easy remote control and real-time monitoring. If there are requirements for system energy conservation, a pulsed air supply strategy can be adopted, cooperating with an air storage tank and a vacuum buffer tank to reduce the continuous operation load of the vacuum pump and the compressor. For high-frequency operation scenarios, the pneumatic control module can also be integrated and encapsulated to improve the anti-interference ability and maintenance convenience of the overall system.

[0061] A paper feeder vacuum flat belt conveying device 3 is arranged on the left side of the sheet transfer gripper table 4. The printed sheets are conveyed in a fish-scale stacking manner on this device, that is, the latter printed sheet 1 is located below the former printed sheet 2 and is sequentially fed into the sheet transfer gripper table 4 area for subsequent buffering and positioning processing in a covering state.

[0062] The paper feeder vacuum flat belt conveying device 3 arranges a continuously running vacuum flat belt, so that the printed sheets are orderly discharged in a stacked arrangement. The latter printed sheet 1 is placed under the former printed sheet 2 to form a fish-scale conveying structure. This structure ensures that the printed sheets will not warp or jam with each other at high speeds, especially suitable for thick printed sheets such as iron sheets. Through the vacuum adsorption method, the printed sheets accurately enter the sheet transfer gripper table 4 area along the specified path and are smoothly docked with the double-row vacuum conveyor belt, providing a stable basis for subsequent positioning and buffering.

[0063] The fish-scale conveying method is adopted to make the layout of the printed sheets more compact and regular, which is conducive to continuous paper feeding and improves the paper feeding efficiency. At the same time, it can reduce the interference and rubbing between the printed sheets, effectively avoiding the problems of printed sheet corner folding or surface scratching, especially significant when conveying or processing thick media such as iron sheets at high speed. It is seamlessly connected with the double-row vacuum conveyor belt in the subsequent transfer gripper table 4 area to build a complete, continuous and efficient conveying path, laying a good foundation for realizing subsequent zero-speed buffer positioning.

[0064] A front gauge adjusting component is arranged on the left side of the installation frame 42. This component includes a support shaft 33, an adjusting plate 34, a return force receiving plate 35 and a threaded rod 43. The support shafts 33 are symmetrically arranged on both sides of the threaded rod 43, and the adjusting plate 34 is installed on the support shafts 33 by a sliding connection method. The front gauge 7 is fixed to the inner side of the return force receiving plate 35. A guide shaft 47 is arranged on the outer side of the return force receiving plate 35. The guide shaft 47 penetrates to the outer side of the adjusting plate 34, and a second spring 46 is assembled on it, which is used to absorb the external force received by the front gauge 7 and buffer deformation in case of sudden impact, playing a protective role. A reset member is also arranged between the adjusting plate 34 and the return force receiving plate 35. This reset member can be a rebounder, a nitrogen cylinder or a cylinder, which is used to quickly reset the return force receiving plate 35 after buffering. Two adjusting nuts 45 are arranged on the threaded rod 43, which are used to fix or adjust the position of the adjusting plate 34.

[0065] When the printed sheet moves at high speed and approaches the front gauge 7, if the deceleration buffer is insufficient due to the failure of the air circuit system, the printed sheet may directly impact the front gauge 7. At this time, the second spring 46 can absorb the instantaneous impact force generated by the impact, reduce the stress on the front gauge structure, and prevent damage or deformation. After the return force receiving plate 35 is offset by force, it can be restored to its original position in time through the set reset member, ensuring the positioning accuracy and structural stability. The adjusting plate 34 is fixed at the required position through the adjusting nut 45, and the position and angle of the front gauge component can be flexibly adjusted to meet the positioning requirements of printed sheets of different specifications or thicknesses.

[0066] An elastic buffer and position fine-tuning mechanism is introduced into the front gauge structure, effectively enhancing the anti-impact ability of the front gauge 7 under abnormal impact, protecting it from being easily deformed, improving the printing accuracy and the service life of the equipment. The set reset structure enables it to be quickly restored after buffer deformation, ensuring the stability of continuous production. The adjusting component has a simple structure and is convenient to adjust. The position of the front gauge 7 can be quickly adjusted without disassembling other devices, improving the adjustment efficiency and enhancing the adaptability of the device.

[0067] The reset device of the centering force-receiving plate 35 can adopt an electric or pneumatic feedback device to achieve automatic reset and status monitoring; the second spring 46 can be replaced with a composite material spring or a hydraulic buffer with specific stiffness and stroke according to actual applications to adapt to the buffer performance under higher loads or different environmental conditions; the adjusting plate 34 can be designed as a scale-adjustable type, and cooperate with a quick-locking mechanism to achieve high-precision adjustment; a sliding coating or a ball bushing structure can be provided on the surface of the guide shaft 47 to reduce friction, improve the guide accuracy and response speed.

[0068] Fixing holes 36 are respectively arranged on both side surfaces of the mounting frame 42, and bolts are passed through the fixing holes 36 to firmly mount the mounting frame 42 on the sheet transfer gripper table 9; a telescopic cylinder 48 is arranged on the lower surface of the sheet transfer gripper table 9, and the telescopic end of the telescopic cylinder 48 is connected to the lifting frame 39; guide rods 49 are arranged at the four corners of the lifting frame 39, and the guide rods 49 pass below the mounting frame 42 and provide guiding and supporting functions during the lifting process; the telescopic cylinder 48 provides lifting power for the lifting frame 39, thereby driving the entire adaptive buffer assembly 31 to rise or fall to meet the buffer requirements of different sheet sizes.

[0069] Under the action of a control signal, the telescopic cylinder 48 drives the lifting frame 39 to lift and lower in the vertical direction, and the lifting frame 39 carries the adaptive buffer assembly 31 to move; when the system identifies that the conveyed sheet is a heavy medium such as iron sheet, the control system drives the cylinder to raise the buffer assembly to the working height, so that the buffer assembly 31 is located between the double-row vacuum flat belts and plays a role in buffering and decelerating; when conveying light media such as paper, the cylinder contracts to hide the buffer assembly below the sheet transfer gripper table 9, thereby avoiding unnecessary frictional contact; the guide rods 49 ensure the smoothness of the lifting path and the structural positioning accuracy during the lifting process, and prevent lateral shaking.

[0070] This embodiment enables the adaptive buffer assembly 31 to have a controllable lifting function, enhancing the system's adaptability to the buffer requirements of different types of sheets, such as paper and iron sheet; through the driving of the telescopic cylinder 48 and the coordinated action of the guide rods 49, the smoothness of the lifting mechanism operation and the accuracy of repeated positioning are achieved; the modular installation design is simple, the structure is firm, which is convenient for on-site debugging and maintenance, and at the same time has good system scalability and interchangeability.

[0071] The telescopic cylinder 48 can be replaced with an electric push rod or a servo electric cylinder to achieve higher-precision and faster-response lifting control; the guide rods 49 can also adopt a linear guide rail system or a slider and slide rail structure to improve the anti-wear performance and guide accuracy; the connection of the fixing holes 36 and the bolts can be upgraded to a quick snap-type structure or a track sliding-mounted scheme to improve the installation efficiency and the module interchangeability; according to the use environment and load-bearing requirements, the mounting frame 42 can be optimized with an aluminum alloy, carbon steel or composite material structure.

[0072] Sealing grooves 55 are provided on both end faces of the hollow shaft 50. Sealing rings are assembled in the sealing grooves 55 to provide a sealing effect when the hollow shaft 50 is connected to the damping shaft 44, preventing gas leakage. Threaded holes are also provided on both end faces of the hollow shaft 50 for facilitating the fixed installation of the hollow shaft 50. To limit the installation position of the rubber skin 52, retaining rings 51 are provided at both ends of the hollow shaft 50. The retaining rings 51 can also block both ends of the long groove 54 provided on the outer surface, thereby reducing air leakage during the negative pressure conveying process and improving the adsorption efficiency and system stability.

[0073] The sealing groove 55 and the sealing ring form a closed structure to prevent leakage at the connection between the hollow shaft 50 and the damping shaft 44 due to rotation or air pressure fluctuations, ensuring that the required negative pressure environment is continuously maintained inside the air holes 53 of the hollow shaft. The setting of the threaded holes enables the precise positioning and fixing of the hollow shaft 50 within the adaptive support frame 38, avoiding axial displacement or loosening from affecting the buffering performance. The retaining rings 51 mechanically limit and fix the rubber skin 52 in the predetermined installation area, ensuring that the rubber skin 52 does not shift or deform during operation. At the same time, the long groove 54 is limited within the effective adsorption range, enhancing the local concentration of vacuum adsorption.

[0074] This structural design improves the mechanical stability and sealing performance of the hollow shaft 50, ensuring the airtightness and structural integrity of the system under high-speed conveying or strong adsorption conditions. Through the cooperation of the threaded holes and the sealing rings, it is convenient for the rapid assembly and maintenance of the hollow shaft. The retaining ring structure effectively standardizes the installation boundary of the rubber skin, improves the consistency of the adsorption contact surface, and further enhances the stable control force on the printed sheet, especially suitable for buffering scenarios for processing high-inertia printed sheets such as iron sheets.

[0075] The sealing ring can be made of fluororubber or silicone rubber materials suitable for high-temperature or high-pressure working conditions. The sealing groove structure can also be upgraded to a double-lip seal or a labyrinth structure to further enhance the airtight effect. The threaded holes can be replaced with dowel pin holes and cooperate with spring pins for rapid installation and positioning. The retaining rings 51 can be integrally injection-molded, combined with the pre-embedded assembly of the rubber skin 52, improving the overall integration of the components and simplifying the assembly process. In applications with high protection levels, a sealing cushion layer can be added to the contact surface between the retaining ring and the rubber skin to improve the dust and liquid resistance.

[0076] The method for the printing press to reduce the impact of the printed sheet on the front gauge is achieved through the following steps:

[0077] Step 1: The printed sheet is sent out by the feeder head of the sheet feeder in a fish-scale stacking manner. The latter printed sheet 1 is located below the former printed sheet 2. The former printed sheet 2 first enters the delivery gripper table 4 area at high speed, and the conveying action is completed by the vacuum flat belt conveying device 3 of the sheet feeder.

[0078] Step 2: The sheet is placed on the double-column vacuum conveyor belt on the sheet transfer gripper table, i.e., on the vacuum flat belt 5; through the flat belt air holes 32 provided on the surface of the vacuum flat belt 5, under the negative pressure provided by the air chamber 6, the sheet is adsorbed on the belt surface to achieve stable and controlled guidance, and the direction is aligned with the front gauge 7;

[0079] Step 3: When the sheet is made of heavy materials such as iron sheets, before the sheet approaches the front gauge 7, the system triggers the telescopic cylinder 48 to act, causing the adaptive buffer assembly 31 to rise; the sheet contacts the friction buffer shaft 37 located between the double-column vacuum flat belts, and negative pressure adsorption is generated through the communication between the inside of the hollow shaft 50 and the air chamber 6 through the hollow shaft air holes 53, and together with the rubber skin 52, it realizes the friction buffer effect and achieves the deceleration effect on the sheet;

[0080] Step 4: The vacuum flat belt 5 is driven by the servo motor 21, and its running speed is precisely programmed and controlled by the electrical control system. According to the set compound motion law, the vacuum flat belt 5 gradually decreases from a high speed to zero speed, so that the sheet is positioned at zero speed when contacting the front gauge 7, avoiding damage to the front gauge caused by inertial impact;

[0081] Step 5: If a slight impact still occurs, the second spring 46 in the front gauge adjustment assembly absorbs the impact energy, and at the same time, the force-bearing plate 35 returns to its original position automatically under the action of the resetting components such as a rebounder and a nitrogen cylinder, effectively protecting the structure of the front gauge 7 and reducing errors and equipment losses;

[0082] Step 6: After the sheet is positioned at zero speed, the air control module issues an instruction to switch the solenoid valve 11 to the blowing state, releasing the vacuum adsorption force. The sheet smoothly leaves the area of the sheet transfer gripper table 4 under the push of the air flow and enters the printing process, realizing efficient sheet transfer and precise printing start.

[0083] This method combines the dynamic response of the mechanical structure and the coordinated control of the air circuit system to achieve multi-stage buffering and precise control of the sheet during the process from high-speed conveying to zero-speed positioning; the adaptive buffer assembly realizes deceleration before the sheet enters the positioning area through the dual mechanisms of friction and adsorption; the servo motor dynamically controls the conveyor belt speed to achieve a high-precision control process; the air control system completes the switching of the vacuum adsorption and release states at key nodes to ensure the smooth departure of the sheet from the table; the elastic front gauge structure further absorbs the residual impact to achieve full-process buffer protection and control.

[0084] The overall design of this method is complete and compact, suitable for various sheets of different weights and materials, especially performing well under high-inertia media such as iron sheets; by automatically identifying the sheet state and reasonably mobilizing each buffer mechanism, it realizes an integrated processing flow of "active deceleration + precise positioning + flexible release", significantly improving the printing accuracy, system stability and structural service life; at the same time, without additional external energy consumption, relying on the structural elasticity and adsorption negative pressure to complete the buffering process, it has the advantages of energy conservation and environmental protection.

[0085] The overall working principle of this application is to build a sheet conveying system based on a double-column vacuum flat belt, combined with an adaptive buffer component with adsorption and deceleration capabilities, to achieve the full-process dynamic control of the sheet from high-speed movement to zero-speed positioning; after the sheet is output by the sheet feeder in a fish-scale stacking manner, it is first adsorbed by the vacuum flat belt 5 and guided to move steadily in the direction of the front gauge 7; for heavy sheets such as iron sheets, the adaptive buffer component rises with the telescopic cylinder 48 and intervenes in the conveying path. The hollow shaft 50 and the air chamber 6 form a negative pressure adsorption force, and the surface rubber skin 52 is used to increase the friction force, so as to further enhance the buffering effect on the basis of the adsorption of the vacuum conveyor belt, and achieve the rapid deceleration and attitude control of heavy sheets without increasing the mechanism volume and external energy consumption; subsequently, the servo motor 21 gradually reduces the speed of the vacuum flat belt 5 to zero under the control of the PLC program, so that the sheet contacts the front gauge 7 at zero speed to complete high-precision positioning; if there is a residual impact due to a sudden failure, the front gauge adjustment component provided with the second spring 46 and the reset mechanism will absorb it flexibly and automatically reset to protect the front gauge structure; finally, the vacuum adsorption is released by switching the solenoid valve through the pneumatic control module, and the sheet smoothly enters the printing section; through the coordination of the conveying path, the buffer mechanism, the speed control and the pneumatic circuit module, the whole system realizes the full-closed-loop and high-precision control process of sheet buffering, positioning and transfer.

[0086] The above shows and describes the basic principles, main features and advantages of the present invention. Without departing from the spirit and scope of the present invention, the present invention has various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. A device for a printing press to mitigate the impact of a printed sheet on a front gauge, comprising a paper feeder stand (4), a vacuum flat belt (5), a paper feeder stand seat (9), a front gauge (7) and an adaptive buffer assembly (31), characterized in that: The vacuum flat belt (5) is arranged on a paper feeding platform (4) with an air chamber (6). The vacuum flat belt (5) is symmetrically arranged on the paper feeding platform (4) to form a double-row vacuum conveyor belt. A front gauge (7) is arranged on the left side of the paper feeding platform (4). A paper feeding platform seat (9) is arranged below the paper feeding platform (4). An adaptive buffer component (31) is arranged between the vacuum flat belts (5). The adaptive buffer component (31) includes an adaptive support frame (38), a mounting frame (42), a lifting frame (39) and a friction buffer shaft (37). The friction buffer shaft (37) is arranged on the adaptive support frame (38) at equal intervals. The friction buffer shaft (37) includes a hollow shaft (50), a rubber skin (52) and a damping shaft (44). The two ends of the hollow shaft (50) are connected to the adaptive The self-adaptive support frame (38) is connected to the hollow shaft (50), the rubber skin (52) is arranged on the outer surface of the hollow shaft (50) along the circumferential direction, and long grooves (54) are left between the rubber skins (52), and hollow shaft air holes (53) connected to the inner cavity of the hollow shaft (50) are arranged at equal intervals in the long grooves (54), and connecting pipes (41) are respectively arranged on both sides of the self-adaptive support frame (38), and the connecting pipes (41) are connected to the inner cavity of the hollow shaft (50), and one end of the connecting pipe (41) is connected to the interface pipe (10) on the air chamber (6) through an air pipe, and the lifting frame (39) is arranged above the mounting frame (42), and a spring (40) is arranged between the lifting frame (39) and the self-adaptive support frame (38), and the lifting frame (39) can drive the self-adaptive support frame (38) to be hidden in the paper feeding tooth stand (9).

2. The device for reducing the impact of printed sheets on the front gauge of a printing press according to claim 1, characterized in that: A guide drum wheel assembly is arranged on the paper feeding tooth seat (9), and the guide drum wheel assembly comprises a flat belt drum wheel (8), an adjusting screw (28), and a guide wheel shaft (29). The guide wheel shaft (29) is mounted on the paper feeding tooth seat (9) via the adjusting screw (28). The flat belt drum wheel (8) is mounted on the guide wheel shaft (29) via a ball bearing (25). The vacuum flat belt (5) is wound around the flat belt drum wheel (8). A flat belt support wheel (14) is arranged on the paper feeding tooth seat (9), and the flat belt support wheel (14) is located below the vacuum flat belt (5).

3. The device for reducing the impact of printed sheets on the front gauge of a printing press according to claim 2, characterized in that: A flat belt driving wheel seat (18) is arranged on the right side of the paper feeding tooth seat (9), and a flat belt driving group is arranged on the flat belt driving wheel seat (18). The flat belt driving group includes a flat belt driving wheel shaft (24), a driving flat belt wheel (22) and a driven synchronous belt wheel (16). The driving flat belt wheel (22) is installed on the flat belt driving wheel shaft (24) through a ball bearing (25). One end of the flat belt driving wheel shaft (24) is connected to the driven synchronous belt wheel (16) through a common flat key (23). The vacuum flat belt (5) is arranged between the flat belt drum wheel (8) and the driving flat belt wheel (22). A servo drive module is arranged on the flat belt driving wheel seat (18), the servo drive module comprises a synchronous belt (17), a flat belt driving wheel seat (18), a motor seat (19), a driving synchronous belt pulley (20) and a servo motor (21), the servo motor (21) is mounted on the flat belt driving wheel seat (18) through the motor seat (19), the flat belt driving wheel seat (18) is fixedly connected to the paper feeding tooth seat (9), the driving synchronous belt pulley (20) is mounted on the output end of the servo motor (21) through a common flat key (23), and the synchronous belt (17) is arranged between the driving synchronous belt pulley (20) and the driven synchronous belt pulley (16).

4. The device for reducing the impact of printed sheets on the front gauge of a printing press according to claim 1, characterized in that: A flat belt groove (56) corresponding to the air chamber (6) is arranged on the upper surface of the paper feeding tooth table (4); the vacuum flat belt (5) is located in the flat belt groove (56); flat belt air holes (32) distributed at equal intervals are arranged on the surface of the vacuum flat belt (5); the upper plane of the vacuum flat belt (5) and the upper plane of the paper feeding tooth table (4) are located in the same plane; the vacuum flat belt (5) covers the air chamber (6) of the paper feeding tooth table (4) to form a negative pressure vacuum air chamber.

5. The device for reducing the impact of printed sheets on the front gauge of a printing press according to claim 4, characterized in that: The interface pipe (10) of the air chamber (6) is connected to an air control module via an air pipe. The air control module comprises a solenoid valve (11), a vacuum regulating valve (12) and a pressure regulating valve (13). The solenoid valve (11) is connected to the interface pipe (10) of the air chamber (6) via the air pipe. The solenoid valve (11) is connected to the vacuum regulating valve (12) and the pressure regulating valve (13) via the air pipe. The vacuum regulating valve (12) is connected to an external vacuum pump. The pressure regulating valve (13) is connected to an air compressor or a centralized air supply system.

6. The device for reducing the impact of printed sheets on the front gauge of a printing press according to claim 1, characterized in that: A vacuum flat belt conveyor (3) of a paper feeder is arranged on the left side of the paper feeding tooth table (4). Printed sheets are transported on the vacuum flat belt conveyor (3) of the paper feeder. The printed sheets are transported in a fish scale stacking manner, that is, a subsequent printed sheet (1) is stacked and transported below a previous printed sheet (2).

7. The device for reducing the impact of printed sheets on the front gauge of a printing press according to claim 1, characterized in that: A front gauge adjustment assembly is arranged on the left side of the mounting frame (42), and the front gauge adjustment assembly comprises a support shaft (33), an adjustment plate (34), a return force plate (35) and a threaded rod (43), wherein the support shaft (33) is symmetrically arranged on both sides of the threaded rod (43), the adjustment plate (34) is slidably connected to the support shaft (33), the front gauge (7) is fixed on the inner side of the return force plate (35), the outer side surface of the return force plate (35) is arranged with a guide shaft (47), the guide shaft (47) passes through the outer side of the adjustment plate (34), a spring 2 (46) is passed through the guide shaft (47), and an adjustment nut (45) is arranged on the threaded rod (43), and two adjustment nuts (45) are arranged.

8. The device for reducing the impact of printed sheets on the front gauge of a printing press according to claim 7, characterized in that: The two side surfaces of the mounting frame (42) are respectively provided with fixing holes (36), the lower surface of the paper feeding tooth stand (9) is provided with a telescopic cylinder (48), the telescopic end of the telescopic cylinder (48) is connected to the lifting frame (39), and the four corners of the lifting frame (39) are provided with guide rods (49), and the guide rods (49) are passed to the bottom of the mounting frame (42).

9. The device for reducing the impact of printed sheets on the front gauge of a printing press according to claim 1, characterized in that: Sealing grooves (55) are respectively provided on both end surfaces of the hollow shaft (50), a sealing ring is provided in the sealing groove (55), and retaining rings (51) are respectively provided on both ends of the hollow shaft (50).

10. A method for a printing press to mitigate the impact of a printed sheet on a front gauge, characterized in that: The device for reducing the impact of a printed sheet on a front gauge of a printing press as claimed in claim 8 comprises the following steps: Step 1: The printed sheets are fed out by the feeder head of the paper feeder in a fish-scale stacking manner, with the next printed sheet (1) being located below the previous printed sheet (2), and the previous printed sheet (2) entering the paper feeding table (4) area at a high speed; Step 2: The printed sheet is covered on the double-row vacuum conveyor belt on the paper delivery tooth table; the flat belt air holes (32) of the vacuum flat belt (5) will absorb the printed sheet, thereby restricting the printed sheet from moving with the vacuum flat belt (5) and guiding it to be transported along the direction of the front gauge (7); Step 3: If the printed sheet is made of heavy iron sheet material, before approaching the front gauge (7), the telescopic cylinder (48) is activated, the adaptive buffer assembly (31) is raised, and the printed sheet contacts the adaptive buffer assembly (31) arranged between the vacuum flat belts (5); the hollow shaft (50) is connected to the air chamber (6) through the hollow shaft air hole (53) and forms additional adsorption, providing friction and additional adsorption force, and performing passive deceleration and buffering on the printed sheet; Step 4: The servo motor (21) drives the vacuum flat belt (5), and the servo control system controls its running speed to gradually decrease from high speed to zero speed according to a set rule, so that the printed sheet contacts the front gauge (7) at zero speed, completes precise positioning and eliminates collision; Step 5: The front gauge (7) is flexibly buffered and reset. When a slight impact occurs, the front gauge adjustment component buffers and absorbs energy to protect the front gauge from damage; and the front gauge (7) is automatically reset; Step 6: After the zero-speed positioning is completed, the air control module issues a command, the solenoid valve (11) switches to the blowing state, and the vacuum adsorption is released; the printed sheet smoothly leaves the paper feeding table (4) area and enters the formal printing process.

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