Intelligent paper feeding device with paper pre-alignment function

Abstract

The invention relates to the technical field of printing equipment, in particular to an intelligent paper feeding device with a paper pre-alignment function, which comprises a rack, a paper feeding platform, a paper feeding mechanism, a pre-alignment mechanism, a detection unit and a control unit, the pre-alignment mechanism is arranged above the paper feeding platform and comprises an alignment datum plate driven by an alignment driving assembly; the detection unit is used for acquiring paper pile edge position information; the control unit controls the alignment datum plate to horizontally move in the direction perpendicular to the paper conveying direction according to the detection information so as to correct the position of the paper pile. The paper pre-alignment device can automatically complete paper pre-alignment before paper feeding.

Description

Technical Field

[0001] This invention relates to the field of printing equipment technology, specifically to an intelligent paper feeding device with paper pre-alignment function. Background Technology

[0002] With the continuous development of office automation and printing and packaging equipment, the paper feeding device, as a key component, directly affects the overall operating efficiency and paper processing quality. While existing paper feeding devices have achieved some success in single-sheet separation and continuous conveying, there are still significant shortcomings in the initial alignment stage before the paper enters the conveying system. Especially in high-speed, high-volume operations, if the paper stack is not effectively pre-aligned before feeding, it can easily lead to multiple skewed sheets or paper jams, affecting the accuracy of subsequent processes and the stability of equipment operation.

[0003] A search revealed a paper feeding device with publication number CN115838088A. This device uses brush rollers on the front and side guide plates to divide the paper stack into upper and lower layers, and employs a suction mechanism to pick up the bottom layer of cardboard for feeding. While this design alleviates the problem of pressure-induced scratches on the bottom layer of cardboard, its initial alignment of the overall paper stack relies on manual placement or passive edge positioning, lacking an active pre-alignment mechanism. When the edges of the paper stack are uneven or the stack is tilted, the brush rollers can only move the upper layer of cardboard, failing to ensure that the entire stack of paper is in a uniform reference position before feeding, thus affecting feeding consistency and positioning accuracy.

[0004] A search revealed a paper feeding device with publication number CN120534573A, which includes a paper alignment component that can be switched to a paper stop or avoidance position. Alignment is achieved by the reverse movement of the paper feeding mechanism, causing the paper stack to abut against the alignment component. While this structure provides alignment functionality, the alignment action occurs during the paper feeding process and requires the reverse movement of the paper feeding mechanism, increasing control complexity and cycle time. Furthermore, this device lacks integrated intelligent detection or adaptive adjustment capabilities, making it unable to dynamically adjust the alignment strategy based on paper size, thickness, or stacking status, thus failing to meet the demands of highly flexible and intelligent production.

[0005] The aforementioned problems indicate that existing paper feeding devices either lack active pre-alignment functionality or have inefficient and insufficiently intelligent alignment methods, making it difficult to efficiently and accurately correct the paper position before feeding. Therefore, a paper feeding device capable of rapid and accurate adaptive pre-alignment of the paper before feeding is needed. Summary of the Invention

[0006] The purpose of this invention is to provide a leg compression rehabilitation training device to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An intelligent paper feeding device with paper pre-alignment function includes a frame, a paper feeding platform mounted on the frame, a paper feeding mechanism, a pre-alignment mechanism, a detection unit, and a control unit. The pre-alignment mechanism is located above the paper feeding platform. The detection unit includes at least two position sensors, which are spaced apart on the frame perpendicular to the paper feeding direction and located above the paper feeding platform. The detection ends of the position sensors face the edge of the paper stack on the paper feeding platform. The control unit is electrically connected to the detection unit and the pre-alignment mechanism. The paper feeding platform includes a horizontally arranged support plate, and the front edge of the support plate is provided with a... The paper feeding mechanism is located below the support plate and extends into the inlet of the conveyor channel. The pre-alignment mechanism includes at least one alignment drive assembly and an alignment execution assembly driven by the alignment drive assembly. The alignment drive assembly is fixedly mounted on the frame. The alignment execution assembly includes an alignment reference plate and a linear drive module that drives the alignment reference plate to move horizontally along a direction perpendicular to the paper conveying direction. The linear drive module is connected to the alignment drive assembly. The alignment reference plate is a long strip-shaped plate structure with its length direction parallel to the paper conveying direction. A gap is left between its lower end face and the upper surface of the support plate to allow a single sheet of paper to pass through.

[0008] In some embodiments, the alignment execution component further includes a sliding seat and a connecting arm; the sliding seat is slidably mounted on the frame via a guide rail, with the sliding direction perpendicular to the paper feeding direction; the output end of the linear drive module is fixedly connected to the sliding seat; one end of the connecting arm is fixedly connected to the sliding seat, and the other end extends downward and is fixedly connected to the top of the alignment reference plate.

[0009] In some embodiments, the alignment reference plate is connected to the connecting arm via a height adjustment assembly; the height adjustment assembly includes a mounting block fixed to the lower end of the connecting arm, an elongated hole opened in the mounting block in the vertical direction, and a locking bolt passing through the elongated hole and locking the alignment reference plate to the mounting block.

[0010] In some embodiments, the pre-alignment mechanism is provided in two sets; the two sets of pre-alignment mechanisms are respectively located on both sides of the paper feeding platform along the direction perpendicular to the paper conveying direction; the inner surface of the alignment reference plate on each side is a vertical alignment surface.

[0011] In some embodiments, the lower leading edge of the alignment reference plate is provided with an upwardly inclined guide slope.

[0012] In some embodiments, the paper feeding mechanism includes a separating component and a conveying component; the separating component is located below the support plate near the entrance of the conveying channel; the conveying component is located behind the separating component.

[0013] In some embodiments, the separation component includes a negative pressure adsorption chamber and a plurality of adsorption holes disposed on the top of the negative pressure adsorption chamber; the negative pressure adsorption chamber is connected to a negative pressure air source through a pipeline; the conveying component includes a drive roller, a driven roller and a paper feeding motor that drives the drive roller to rotate; the drive roller and the driven roller are arranged opposite each other vertically to form a roller gap for clamping the paper, and the roller gap is located behind the separation component.

[0014] In some embodiments, a rear guide rail is provided on the frame behind the paper feeding platform; the rear guide rail is a vertical plate with its surface perpendicular to the paper feeding direction; the lower edge of the rear guide rail contacts the upper surface of the support plate.

[0015] In some embodiments, the control unit further includes a human-machine interface; the human-machine interface is disposed on the outside of the frame.

[0016] In some embodiments, the alignment drive assembly includes a servo motor and a ball screw pair driven by the servo motor; the nut of the ball screw pair is fixedly connected to the linear drive module or the alignment execution assembly.

[0017] As a further improvement, the detection unit is a linear image sensor or a laser displacement sensor. The scanning lines of the linear image sensor or laser displacement sensor are parallel to the plane of the support plate and perpendicular to the paper feeding direction, enabling it to acquire the positional information of the entire side edge contour of the paper stack in one go, with high measurement accuracy and fast response speed.

[0018] As a further improvement, a rear stop gauge is also provided on the frame behind the paper feeding platform. The rear stop gauge is a vertical plate with its surface perpendicular to the paper feeding direction. The lower edge of the rear stop gauge contacts the upper surface of the support plate. The rear stop gauge is used as a reference for the rear edge of the paper stack during the pre-alignment process, and together with the alignment reference plates on both sides, it achieves complete positioning of the paper stack in two degrees of freedom within the plane of the support plate.

[0019] As a further improvement, the alignment reference plate is connected to the connecting arm via a height adjustment assembly. The height adjustment assembly includes a mounting block fixed to the lower end of the connecting arm, an elongated hole vertically formed in the mounting block, and a locking bolt passing through the elongated hole and locking the alignment reference plate to the mounting block. By loosening the locking bolt and moving the alignment reference plate up and down along the elongated hole, the gap between the lower end face of the alignment reference plate and the support plate can be adjusted to accommodate papers of different thicknesses.

[0020] As a further improvement, the logic processing module of the control unit pre-stores multiple alignment modes. These alignment modes include a fast alignment mode and a fine alignment mode. In fast alignment mode, the control unit drives the alignment reference plate to move at a relatively high speed to the calculated target position. In fine alignment mode, the control unit first drives the alignment reference plate to move at a relatively high speed to near the target position, then moves it at a lower speed to the final target position, and holds it at that position for a preset time to ensure the paper stacks are stably aligned.

[0021] As a further improvement, scales are provided on both sides of the paper feeding platform. The scales are perpendicular to the paper feeding direction and are used for coarse positioning reference when manually placing paper stacks, reducing the initial offset and thus shortening the stroke and time of the pre-alignment mechanism.

[0022] As a further improvement, a protective cover is provided on the outside of the alignment drive assembly of the pre-alignment mechanism. The protective cover is fixed to the frame and encloses most of the structure of the alignment drive assembly and the linear drive module, exposing only the connecting arm and the alignment reference plate, thus serving as a dustproof and safety protection.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention relates to an intelligent paper feeding device with pre-alignment function. Through a closed-loop control system consisting of a detection unit, a control unit, and a pre-alignment mechanism, the device proactively detects and corrects the paper stack position before the feeding action begins. Its structure uses an independent alignment drive component to move an alignment reference plate along a precise guide path, achieving direct and rapid pushing against the side edges of the paper stack. The independently controllable alignment reference plates on both sides can perform single-sided pushing or double-sided clamping alignment according to the actual offset of the paper stack, offering strong adaptability. The device modularly integrates the pre-alignment function above the paper feeding platform, without interfering with subsequent paper separation and conveying processes, resulting in a compact and reasonable structural layout. The detection unit provides real-time feedback on the alignment effect, and the control unit performs logical judgments and issues commands, forming an intelligent adaptive alignment strategy. The entire device completes precise paper positioning before feeding, eliminating the risks of skewed paper feeding, multiple sheets fed, and paper jams caused by incorrect initial paper stack positions. This significantly improves the consistency and positioning accuracy of paper feeding, ensuring the operational stability and production efficiency of the equipment under high-speed continuous operation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of an intelligent paper feeding device with paper pre-alignment function according to the present invention. Figure 2 This is a partial structural diagram of the pre-alignment mechanism and the paper feeding platform according to an embodiment of this application; Figure 3 This is a side view of an intelligent paper feeding device with paper pre-alignment function according to the present invention. Figure 4 This is an exploded view of the alignment reference plate and the height adjustment assembly.

[0025] Explanation of reference numerals in the attached drawings: 1. Frame; 2. Paper feeding platform; 3. Support plate; 4. Conveyor channel inlet; 5. Paper feeding mechanism; 6. Pre-alignment mechanism; 7. Alignment drive assembly; 8. Alignment execution assembly; 9. Alignment reference plate; 10. Linear drive module; 11. Detection unit; 12. Position sensor; 13. Control unit; 14. Guide rail; 15. Sliding seat; 16. Connecting arm; 17. Separation assembly; 18. Conveying assembly; 19. Negative pressure adsorption chamber; 20. Adsorption hole; 21. Driven roller; 22. Driven roller; 23. 24. Paper feed motor; 25. Vent hole; 26. Human-machine interface; 27. Guide slope; 28. Flexible buffer layer; 29. ​​Rear stop; 30. Height adjustment assembly; 31. Mounting block; 32. Long slot; 33. Locking bolt; 34. Protective cover; 35. Paper; 36. Drive motor; 37. Lead screw; 38. Nut seat; 39. Guide rod; 40. Elastic element; 41. Paper pressure roller; 42. Proximity switch; 43. Power module; 44. Support leg; 45. Adjustment knob; 46. Electric push rod; 47. Displacement sensor. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art should understand that the embodiments described below are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] Please see Figures 1 to 4 As shown, this invention provides an intelligent paper feeding device with paper pre-alignment function. Its overall structure includes a frame 1, a paper feeding platform 2 mounted on the frame 1, a paper feeding mechanism 5 positioned below the paper feeding platform 2 for separating and conveying paper 34, a pre-alignment mechanism 6 positioned above the paper feeding platform 2, a detection unit 11 mounted on the frame 1 for detecting the position information of the paper 34, and a control unit 13 electrically connected to the detection unit 11 and the pre-alignment mechanism 6. The frame 1, as the basic support structure of the entire device, is welded from high-strength carbon steel, possessing good rigidity and shock resistance. The bottom of the frame 1 is equipped with multiple support legs 44, which are installed at the bottom of the frame 1 via threaded connections. Each support leg 44 is equipped with an adjustable height knob 45, allowing the device to be leveled under different ground conditions, ensuring that the upper surface of the support plate 3 is precisely horizontal.

[0028] like Figure 1As shown, the paper feeding platform 2 is fixedly installed in the middle area of ​​the frame 1. Its main body is a rectangular plate-shaped support plate 3, which is made of aluminum alloy and anodized to enhance surface hardness and wear resistance. The flatness of the upper surface of the support plate 3 is controlled within 0.05mm to ensure that the paper 34 is placed stably on its surface. The front edge of the support plate 3 extends forward along the paper conveying direction to form a conveying channel inlet 4. This conveying channel inlet 4 is a narrow and long opening, slightly wider than the thickness of a single sheet of paper 34, which facilitates the smooth entry of the separated paper into the subsequent conveying path. The upper surface of the support plate 3 is coated with a low-friction coefficient polytetrafluoroethylene coating, or is embedded with multiple 8mm diameter ball bearings. These ball bearings are evenly distributed on the surface of the support plate 3 and can rotate freely, significantly reducing the sliding friction resistance between the paper 34 and the support plate 3, which is beneficial for the smooth movement of the paper stack during the pre-alignment process.

[0029] The paper feeding mechanism 5 is located below the support plate 3, with its paper feeding end extending upward through the support plate 3 and into the inlet 4 of the conveying channel. The paper feeding mechanism 5 includes a separation component 17 and a conveying component 18. The separation component 17 is located below the support plate 3 near the inlet 4 of the conveying channel, and its core structure is a negative pressure adsorption chamber 19. The negative pressure adsorption chamber 19 is a sealed box structure that forms a negative pressure space inside. The top of the negative pressure adsorption chamber 19 has multiple circular adsorption holes 20 arranged in a matrix, with a total of twelve holes and a diameter of 3 mm. The support plate 3 has vertically penetrating vent holes 24 in the area corresponding to the adsorption holes 20. The number and position of the vent holes 24 correspond one-to-one with the adsorption holes 20. The diameter of the vent holes 24 is 4 mm, slightly larger than that of the adsorption holes 20, to ensure that the negative pressure can be effectively transmitted to the bottom surface of the paper 34. The negative pressure adsorption chamber 19 is connected to an external vacuum pump through a flexible pipeline. When the vacuum pump is started, the negative pressure acts on the lower surface of the bottom layer of paper 34 through the vent 24, causing it to generate a downward adsorption force, thereby achieving effective separation from other upper layers of paper.

[0030] The conveying assembly 18 is located behind the separating assembly 17, i.e., on the side away from the conveying channel inlet 4. The conveying assembly 18 includes a drive roller 21, a driven roller 22, and a paper feeding motor 23 that drives the drive roller 21 to rotate. The drive roller 21 and the driven roller 22 are arranged vertically opposite each other, forming a gap between them to clamp the paper 34. The drive roller 21 is mounted on the output shaft of the paper feeding motor 23, which is a DC brushless servo motor fixed to the inner wall of the frame 1. The driven roller 22 is mounted on a vertically floating support via a bearing seat, and a downward preload is applied by an elastic element 39, allowing it to adapt to paper 34 of different thicknesses. When the paper 34 that has been adsorbed and separated is pushed between the drive roller 21 and the driven roller 22, the two rollers work together to clamp it and accelerate its forward conveying, completing the power transmission process from rest to motion.

[0031] See also Figure 1 and Figure 2 The pre-alignment mechanism 6 is located above the paper feeding platform 2 and is used to correct the position of the paper stack placed on the support plate 3 before the paper feeding mechanism 5 is started. The pre-alignment mechanism 6 includes two sets of symmetrically arranged alignment execution components 8, each set of alignment execution components 8 is driven by the alignment drive component 7. The alignment drive component 7 is a servo motor, and its output shaft is connected to the linear drive module 10 through a coupling. The linear drive module 10 adopts a ball screw pair structure, including a lead screw 36, a nut seat 37, and a pair of parallel guide rods 38. The lead screw 36 is arranged horizontally perpendicular to the paper feeding direction, and its two ends are supported on the frame 1 by bearing seats. One end is directly connected to the output shaft of the alignment drive component 7. The nut seat 37 is sleeved on the lead screw 36 and forms a helical pair with the lead screw 36. The guide rod 38 is set parallel to the lead screw 36, and its two ends are also fixed to the frame 1. A linear bearing is provided on the nut seat 37. The linear bearing is sleeved on the outer periphery of the guide rod 38 to achieve guiding constraint and prevent the nut seat 37 from rotating with the lead screw 36.

[0032] The alignment execution assembly 8 also includes a sliding seat 15, a connecting arm 16, and an alignment reference plate 9. The sliding seat 15 is a rectangular metal block, its bottom fixed to a nut seat 37 by screws, and its top has mounting holes for mounting the connecting arm 16. The connecting arm 16 is an L-shaped bent plate made of stainless steel, one end of which is bolted to the top of the sliding seat 15, and the other end extends vertically downwards. The alignment reference plate 9 is connected to the lower end of the connecting arm 16 via an automatic height adjustment assembly 29, thereby automatically adjusting the gap between the lower surface of the alignment reference plate 9 and the upper surface of the support plate 3. The automatic height adjustment assembly 29 includes a mounting block 30, an electric push rod 46, and a displacement sensor 47. The mounting block 30 is a rectangular metal block fixed to the lower end of the connecting arm 16. The cylinder of the electric push rod 46 is fixed to the mounting block 30, and its push rod end is fixedly connected to the top of the alignment reference plate 9. The displacement sensor 47 is a miniature linear displacement sensor, fixed on the mounting block 30. Its detection end contacts the top of the alignment reference plate 9, used to monitor the vertical position of the alignment reference plate 9 in real time. The control unit 13 automatically controls the extension and retraction of the electric push rod 46 according to preset paper thickness parameters or paper stack height information obtained through the detection unit 11, precisely adjusting the gap between the lower end face of the alignment reference plate 9 and the upper surface of the support plate 3 to the target value (e.g., within the range of 1.0mm to 1.5mm). This structure allows the device to automatically adapt to different paper weights and thicknesses 34 during production line operation, such as from 70g ordinary printing paper to 300g cardstock, without manual intervention.

[0033] The alignment reference plate 9 is a long, strip-shaped structure, 200mm long, 30mm high, and 10mm thick, made of aluminum alloy. The length of the alignment reference plate 9 is parallel to the paper feeding direction, and the height of its lower end face from the upper surface of the support plate 3 is adjusted by the aforementioned automatic height adjustment component 29. The inner surface of the alignment reference plate 9 is a vertically arranged alignment surface, which has been precision ground to achieve a flatness of 0.02mm, ensuring uniform force distribution when in contact with the side edge of the paper 34. A guide slope 26 is provided at the lower leading edge of the alignment reference plate 9. The guide slope 26 has an inclination angle of 30 degrees and a length of 5mm. Its function is to gradually cut into the edge of the paper stack during the initial movement of the alignment reference plate 9 if there is a large offset in the paper stack, avoiding rigid collisions that could cause the paper to curl or jam. A flexible buffer layer 27 is detachably attached to the alignment surface of the alignment reference plate 9. The flexible buffer layer 27 is molded from polyurethane material with a Shore hardness of 60A and a thickness of 1.5mm. It is bonded to the surface of the alignment reference plate 9 with double-sided tape and can provide elastic cushioning when pushing against the paper 34, effectively preventing indentations or damage to the edges of the paper.

[0034] Two sets of pre-alignment mechanisms 6 are located symmetrically on the left and right sides of the paper feeding platform 2 along the direction perpendicular to the paper conveying direction. The alignment reference plate 9 on each side can be moved independently, allowing for the selection of different alignment strategies based on actual detection results: when the paper stack shifts to the left, the right alignment reference plate 9 moves to the left to push against the right edge of the paper stack, while the left alignment reference plate 9 remains stationary as a static reference; the reverse is also true. When rapid centering is required, the paper stack can be clamped by synchronous movement of both sides, achieving bidirectional push alignment. This dual-sided independent drive structure greatly enhances the device's adaptability to different types of offsets.

[0035] The detection unit 11 includes at least two position sensors 12, which are laser displacement sensors characterized by high precision and non-contact measurement. The two position sensors 12 are respectively mounted on fixed brackets on the left and right sides of the paper feeding platform 2 on the frame 1, with their detection ends facing the paper stack side edges on the support plate 3. The scanning lines are parallel to the plane of the support plate 3 and perpendicular to the paper feeding direction. The sampling frequency of the position sensors 12 is 50kHz, and the measurement resolution reaches 0.5μm, enabling real-time acquisition of the actual position coordinates of the paper stack side edges. The detection unit 11 can also be replaced with a linear array image sensor, whose photosensitive elements are arranged perpendicular to the feeding direction, capturing the paper stack side edge contour through optical imaging, and then calculating the edge position.

[0036] The control unit 13 is mounted on the outer wall of the frame 1. Its main body is an industrial-grade embedded controller with a built-in ARM Cortex-A53 quad-core processor running a Linux real-time operating system. The control unit 13 connects to the detection unit 11 via an RS-485 communication interface to receive raw data from the position sensor 12. Simultaneously, it connects to the alignment drive assembly 7, the electric push rod 46 in the automatic height adjustment assembly 29, and the paper feed motor 23 via a pulse signal output port to send motion control commands. The control unit 13 also includes a human-machine interface 25, a 7-inch color touchscreen fixed to an easily observable position on the front of the frame 1. Operators can set system parameters through the human-machine interface 25, such as preset alignment tolerance thresholds (default ±0.3mm), and monitor the system's operating status. Standard paper size parameters (e.g., A4, B5, or specific packaging cardboard sizes) can be directly transmitted to the control unit 13 via industrial Ethernet or fieldbus interfaces from the production line main control system or upstream equipment, achieving parameter synchronization across the entire production line without the need for manual input on this device.

[0037] The control unit 13 has a built-in logic processing module. This module first determines the position of the preset reference centerline based on the received standard size parameters. Then, it substitutes the data of the left and right edge positions of the paper stack collected in real time by the detection unit 11 into the calculation formula to obtain the offset ΔX and offset direction of the current paper stack centerline relative to the preset reference centerline. If |ΔX| is greater than the preset alignment tolerance threshold, it is determined that an alignment action needs to be performed, and a corresponding displacement control command is generated and sent to the corresponding alignment drive component 7. The logic processing module has multiple pre-stored alignment modes, including a fast alignment mode and a fine alignment mode. In the fast alignment mode, the control unit 13 drives the alignment reference plate 9 to move to the target position at a maximum speed of 60 mm / s. In the fine alignment mode, the control unit 13 first moves at high speed to a distance of 2 mm from the target position, then switches to a low speed of 5 mm / s for fine approximation, and maintains constant pressure for 0.8 s after reaching the final position to ensure that the paper stack is fully and stably aligned before releasing the command, ensuring stable and reliable alignment accuracy.

[0038] See also Figure 3 and Figure 4A rear guide rail 28 is also installed on the frame 1 behind the paper feeding platform 2. The rear guide rail 28 is a vertically erected steel plate with a thickness of 5mm. Its surface is perpendicular to the paper feeding direction, and its lower edge is in complete contact and fits against the upper surface of the support plate 3. The rear guide rail 28 is fixed to the frame 1 with screws and its position is not adjustable. During the pre-alignment process, the rear edge of the paper stack abuts against the front surface of the rear guide rail 28 as a longitudinal positioning reference. Combined with the lateral pushing action of the alignment reference plates 9 on both sides, the paper stack is completely constrained in the X and Y degrees of freedom in the plane of the support plate 3, achieving five constraint points in the six-point positioning principle (the rear guide rail provides two constraints, the two alignment reference plates on both sides each provide one constraint, and the support plate 3 itself provides three supports), thereby completely eliminating the rotational and translational degrees of freedom of the paper stack and ensuring that the paper stack is in a consistent spatial posture before each paper feeding.

[0039] The paper feeding platform 2 has scales on its left and right edges. These scales are etched directly onto the sides of the support plate 3, with the scale unit being millimeters, ranging from 0mm to 300mm, and the scale lines are clearly visible. The zero point of the scale corresponds to the preset paper feeding baseline position. In automated production lines, when upstream equipment (such as automatic feeding robots or conveyor belts) places the paper stack on the support plate 3, visual assistance positioning can be performed by referring to the scales, reducing the initial offset, thereby shortening the stroke and response time of the pre-alignment mechanism 6 and improving the overall line efficiency.

[0040] Most of the moving parts of the alignment drive assembly 7 and the linear drive module 10 are covered by a protective cover 33. The protective cover 33 is a U-shaped shell formed by sheet metal stamping, made of galvanized steel plate, and fixed to the frame 1 with screws. The protective cover 33 has an avoidance notch only at the protrusion of the connecting arm 16, and the rest is completely sealed, which serves to prevent dust, foreign object intrusion, and ensure operational safety. A proximity switch 42 is also provided inside the protective cover 33. The proximity switch 42 is fixed to the inner side wall of the protective cover 33 and is used to detect whether the sliding seat 15 has run to its limit position. When the sliding seat 15 touches the sensing end of the proximity switch 42, the signal is fed back to the control unit 13, which immediately cuts off the power supply to the alignment drive assembly 7 to prevent overtravel damage to the mechanical structure.

[0041] The separating component 17 in the paper feeding mechanism 5 also includes a pressure roller 40, which is positioned above the support plate 3 and located in the rear region of the paper stack. The pressure roller 40 is hinged to the frame 1 via a swing arm and is subjected to downward pressure by a torsion spring, ensuring that the pressure roller 40 always gently presses against the top of the paper stack. The function of the pressure roller 40 is to prevent the upper layer of paper from being sucked up along with the lower layer of paper during the negative pressure adsorption process, thus preventing multiple sheets from being fed. The wheel cover of the pressure roller 40 is covered with a rubber layer, which increases friction while protecting the paper surface.

[0042] The power module 43 is located inside the rack 1, providing a stable DC and AC power output for the entire device. The power module 43 converts external 220V AC power to +24V DC power to supply the sensors and control system, and +12V to the touchscreen, while also reserving one 220V output for the vacuum pump. All electrical wiring is centrally routed through cable trays to avoid interference and wear.

[0043] The device of this invention, as an automated paper feeding step device in a packaging box printing production line, operates on the following principle: Before operation, upstream automated equipment (such as a robotic arm or conveyor belt) automatically places the paper stack to be processed onto the support plate 3 of the paper feeding platform 2, ensuring that the rear edge of the paper stack is as close as possible to the rear guard 28. The standard size parameters of the paper are automatically sent from the production line main control system to the control unit 13 of this device. After the device is powered on, the control unit 13 initializes, and the detection unit 11 (position sensor 12) starts working, scanning and acquiring the current position data of the left and right edges of the paper stack in real time, and transmitting the data to the control unit 13. At the same time, based on the received paper thickness information, the control unit 13 automatically controls the electric push rod 46 in the automatic height adjustment assembly 29 to adjust the alignment reference plates 9 on both sides to a suitable height gap.

[0044] During operation, the logic processing module of control unit 13 calculates the actual offset ΔX of the paper stack centerline based on the preset reference centerline and the real-time detected edge position. If |ΔX| does not exceed the preset tolerance threshold, the paper stack position is deemed qualified, and control unit 13 directly sends a start command to the paper feeding motor 23 of the paper feeding mechanism 5 to begin the paper feeding process. If |ΔX| exceeds the preset tolerance threshold, control unit 13 generates corresponding control commands based on the offset direction and magnitude, driving the alignment drive assembly 7 on the corresponding side to move. The alignment drive assembly 7 converts the rotational motion into the linear motion of the nut seat 37 through the linear drive module 10 (ball screw pair), thereby driving the sliding seat 15, connecting arm 16, and alignment reference plate 9 to move towards the side edge of the paper stack. The guide slope 26 at the lower end of the alignment reference plate 9 first contacts the edge of the paper stack, guiding it to enter smoothly. Then, under the protection of the flexible buffer layer 27, the vertical alignment surface pushes against the side edge of the paper stack with a set force until the centerline of the paper stack is corrected to the tolerance range. During this process, the alignment reference plate 9 on the other side can serve as a static reference or move in tandem with the other side. After the alignment is completed, the control unit 13 confirms that the paper stack position meets the requirements and then instructs the paper feeding mechanism 5 to start working. The separation component 17 of the paper feeding mechanism 5 separates the bottom layer of paper by negative pressure adsorption, and the driving roller 21 and driven roller 22 of the conveying component 18 clamp and convey the paper forward, completing the single sheet feeding and sending the paper to the downstream printing or processing station.

[0045] After the work is completed, a single sheet of paper is fed out. According to the instructions of the control unit 13, the pre-alignment mechanism 6 drives the alignment reference plate 9 back to the initial waiting position, ready to perform the alignment action of the next round of paper stacks. This cycle is repeated to achieve continuous and fully automatic paper pre-alignment and conveying operations synchronized with the production line rhythm.

[0046] In another embodiment of the present invention, the linear drive module 10 can be replaced with a synchronous belt linear module. The synchronous belt linear module includes a drive wheel, a driven wheel, a synchronous belt, and a movable slider fixedly connected to the synchronous belt. The output shaft of the alignment drive assembly 7 is connected to the drive wheel, driving the synchronous belt to circulate, and the movable slider reciprocates along the guide rail direction accordingly. This structure has the advantages of fast response speed and low operating noise, and is suitable for high-speed packaging box printing production lines with higher dynamic performance requirements. The remaining structure is basically the same as in the first embodiment, and will not be described again here.

[0047] In another embodiment of the present invention, the detection unit 11 may use a single linear array image sensor instead of multiple position sensors 12. This linear array image sensor is positioned laterally across the paper feeding platform 2, with its light-sensing direction vertically downwards, and the scanning line covering the entire width of the paper stack. Complete contour information of the four edges of the paper stack can be obtained in a single imaging operation, which can be used not only for lateral alignment control but also, to some extent, for determining the paper skew angle, thereby guiding the operation of the rotation correction mechanism. This embodiment further improves the integration and intelligence of the detection, adapting to more complex packaging box and cardboard alignment requirements.

[0048] In another embodiment of the invention, the alignment reference plate 9 can be connected in a floating structure. An elastic element 39, such as a compression spring or disc spring, is added between the connecting arm 16 and the alignment reference plate 9, allowing the alignment reference plate 9 to have a certain axial compression stroke when contacting the edge of the paper stack. When the pushing force exceeds a set threshold, the alignment reference plate 9 automatically retracts, preventing mechanical damage or paper deformation due to overload. This structure is particularly suitable for automated processing of fragile paper materials or high-grade packaging cardboard.

[0049] In summary, this invention, by constructing a closed-loop control system consisting of a detection unit 11, a control unit 13, and a pre-alignment mechanism 6, achieves active sensing and precise control of the paper stack position at the physical structure level. The components work collaboratively through clear mechanical connections, spatial layout, and motion coupling, forming a highly integrated and automated paper feeding front-end positioning module. The entire device is compact and fully functional. As an automated step in a packaging box printing production line, it solves problems such as paper feeding deviation, paper jams, and double sheets caused by inaccurate initial paper stack positioning, providing a precise and stable paper supply guarantee for subsequent high-speed continuous printing, die-cutting, and box gluing operations.

[0050] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. An intelligent paper feeding device with paper pre-alignment function, comprising a frame (1), a paper feeding platform (2) disposed on the frame (1), a paper feeding mechanism (5), a pre-alignment mechanism (6), a detection unit (11), and a control unit (13); the pre-alignment mechanism (6) is disposed above the paper feeding platform (2); the detection unit (11) comprises at least two position sensors (12), the position sensors (12) being arranged at intervals on the frame (1) perpendicular to the paper feeding direction and located above the paper feeding platform (2), the detection ends of the position sensors (12) being disposed facing the paper stack side edge on the paper feeding platform (2); the control unit (13) being electrically connected to the detection unit (11) and the pre-alignment mechanism (6); characterized in that, The paper feeding platform (2) includes a horizontally arranged support plate (3), and the front edge of the support plate (3) is provided with a forward-extending conveying channel inlet (4). The paper feeding mechanism (5) is located below the support plate (3), and its paper feeding end extends into the conveying channel inlet (4). The pre-alignment mechanism (6) includes at least one alignment drive component (7) and an alignment execution component (8) driven by the alignment drive component (7). The alignment drive component (7) is fixedly installed on the frame (1). The alignment execution component (8) includes an alignment reference plate (9) and a linear drive module (10) that drives the alignment reference plate (9) to move horizontally along a direction perpendicular to the paper conveying direction. The linear drive module (10) is connected to the alignment drive component (7) in a transmission manner. The alignment reference plate (9) is a long strip plate structure, and its length direction is parallel to the paper conveying direction. A gap is left between its lower end face and the upper surface of the support plate (3) for a single sheet of paper (34) to pass through.

2. The intelligent paper feeding device with paper pre-alignment function according to claim 1, characterized in that, The alignment execution component (8) also includes a sliding seat (15) and a connecting arm (16); the sliding seat (15) is slidably mounted on the frame (1) via a guide rail (14), and the sliding direction is perpendicular to the paper feeding direction; The output end of the linear drive module (10) is fixedly connected to the slide seat (15); one end of the connecting arm (16) is fixedly connected to the slide seat (15), and the other end extends downward and is fixedly connected to the top of the alignment reference plate (9).

3. The intelligent paper feeding device with paper pre-alignment function according to claim 2, characterized in that, The alignment reference plate (9) is connected to the connecting arm (16) via a height adjustment assembly (29); the height adjustment assembly (29) includes a mounting block (30) fixed to the lower end of the connecting arm (16), an elongated hole (31) opened vertically on the mounting block (30), and a locking bolt (32) passing through the elongated hole (31) and locking the alignment reference plate (9) to the mounting block (30).

4. The intelligent paper feeding device with paper pre-alignment function according to claim 1, characterized in that, The pre-alignment mechanism (6) is provided in two sets; the two sets of pre-alignment mechanisms (6) are located on both sides of the paper feeding platform (2) along the direction perpendicular to the paper feeding direction; the inner side of the alignment reference plate (9) on each side is a vertical alignment surface.

5. The intelligent paper feeding device with paper pre-alignment function according to claim 4, characterized in that, The lower leading edge of the alignment reference plate (9) is provided with an upwardly inclined guide slope (26).

6. The intelligent paper feeding device with paper pre-alignment function according to claim 1, characterized in that, The paper feeding mechanism (5) includes a separation component (17) and a conveying component (18); the separation component (17) is located below the support plate (3) near the inlet (4) of the conveying channel; the conveying component (18) is located behind the separation component (17).

7. The intelligent paper feeding device with paper pre-alignment function according to claim 6, characterized in that, The separation component (17) includes a negative pressure adsorption chamber (19) and a plurality of adsorption holes (20) disposed on the top of the negative pressure adsorption chamber (19); the negative pressure adsorption chamber (19) is connected to a negative pressure air source through a pipeline; the conveying component (18) includes an active roller (21), a driven roller (22) and a paper feeding motor (23) that drives the active roller (21) to rotate; the active roller (21) and the driven roller (22) are arranged opposite each other vertically to form a roller gap for clamping the paper (34), and the roller gap is located behind the separation component (17).

8. The intelligent paper feeding device with paper pre-alignment function according to claim 1, characterized in that, The frame (1) is also provided with a rear guide (28) behind the paper feeding platform (2); the rear guide (28) is a vertical plate with its surface perpendicular to the paper feeding direction; the lower edge of the rear guide (28) is in contact with the upper surface of the support plate (3).

9. The intelligent paper feeding device with paper pre-alignment function according to claim 1, characterized in that, The control unit (13) also includes a human-machine interface (25); the human-machine interface (25) is located on the outside of the frame (1).

10. The intelligent paper feeding device with paper pre-alignment function according to claim 1, characterized in that, The alignment drive assembly (7) includes a servo motor (24) and a ball screw pair driven by the servo motor (24); the nut of the ball screw pair is fixedly connected to the linear drive module (10) or the alignment execution assembly (8).

Images