A carton printing apparatus with adjustable printing roller gap

Abstract

The application provides a carton printing device capable of adjusting the printing roller gap, and relates to the technical field of carton printing. The carton printing device capable of adjusting the printing roller gap comprises a rack, the front wall and the rear wall of which are provided with long circular holes; a rotating shaft which is slidingly connected to the inner side walls of the two groups of long circular holes and extends towards the front side and the rear side of the rack at the front end and the rear end of the rotating shaft respectively, and the outer wall of the rotating shaft is used for arranging a printing roller; and an adjusting structure which is arranged between the end of the rotating shaft extending out of the outer wall of the rack and the rack. According to the application, a rigid synchronous rod is introduced as a single driving source, and a slope conversion assembly which is linked with the two ends of the printing roller on the two sides of the synchronous rod is used, so that the absolute synchronism of the lifting movement of the two ends of the printing roller is forcedly ensured from the mechanical structure, and the small horizontal displacement of the single driving source is accurately and sensitively converted into the required vertical fine adjustment of the printing roller by using the low-friction and high-rigidity characteristics.

Description

Technical Field

[0001] This invention relates to the field of carton printing technology, specifically to a carton printing apparatus with adjustable printing roller gap. Background Technology

[0002] In the corrugated packaging and printing industry, the printing roller and its pressure regulating device—the core components for achieving image and text transfer—have always been key technological links in equipment automation and printing quality control. For a long time, this type of equipment has evolved from purely manual mechanical adjustment to semi-automatic and fully automatic adjustment. Early adjustments relied heavily on the operator's experience, manually rotating independent screws or eccentric wheels on both sides of the equipment to adjust the gap at both ends of the printing roller. This process was cumbersome and inconsistent. With the widespread adoption of servo motors and CNC technology, modern mid-to-high-end equipment commonly uses motor-driven automatic adjustment methods. For example, PLC controls independent servo motors or electric push rods on both sides to drive the lifting mechanisms at both ends of the printing roller, and the gap parameters are digitally set and stored on the human-machine interface (HMI), greatly improving operational convenience and production standardization.

[0003] However, even in existing automated adjustment equipment, a fundamental and long-standing drawback affecting the stability of print quality remains unresolved: the problem of synchronizing the adjustment at both ends of the printing roller's axial direction. Because such equipment typically uses two independent drive units (such as two servo motors or electric cylinders) acting on both ends of the printing roller, despite the control system's attempts to send synchronization commands, slight differences inevitably exist between the two drive units in terms of mechanical manufacturing precision, assembly clearance, transmission chain rigidity, and response characteristics. Under the long-term, high-frequency reciprocating adjustment and the vibration environment of high-speed printing, these slight differences are amplified, causing deviations in the actual displacement at both ends of the printing roller, thus disrupting the parallelism of the roller system. The direct consequence is uneven distribution of printing pressure along the length of the roller, resulting in localized dot gain, uneven ink color, and even the crushing of corrugated cardboard due to excessive localized pressure, severely impacting product quality and material strength. Simultaneously, this asynchrony also exacerbates the wear and tear on mechanical components, increasing equipment maintenance costs and the frequency of precision calibration.

[0004] Therefore, it is necessary to fundamentally improve and optimize the structure of existing automatic printing roller gap adjustment devices. The core objective of this optimization is to completely eliminate the vulnerability of relying on bilateral electronic synchronization from the top-level design of the mechanical transmission principle, and to invent a new mechanism that can physically guarantee the absolute synchronous lifting and lowering of both ends of the printing roller. This mechanism should be able to transmit the power from a single drive source simultaneously and without discrimination or delay to both ends of the roller shaft through an ingenious and highly rigid mechanical design, thereby eliminating all quality problems caused by asynchrony at the root. Simultaneously, the new structural design must also consider the precision of adjustment, the long-term reliability of operation, and the ease of maintenance, in order to improve printing quality and stability while reducing the overall life-cycle usage and maintenance costs of the equipment, meeting the increasingly stringent technical requirements of modern, high-efficiency printing production for core execution units. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a carton printing apparatus with adjustable printing roller gap, solving the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a carton printing apparatus with adjustable printing roller gap, comprising:

[0007] The frame has oblong holes on both its front and rear walls.

[0008] A rotating shaft is slidably connected to the inner wall of the two sets of elongated holes, and the front and rear ends of the rotating shaft extend toward the front and rear sides of the frame, respectively. The outer wall of the rotating shaft is used to set the printing roller.

[0009] An adjustment structure is provided between the end of the rotating shaft extending to the outer wall of the frame and the frame;

[0010] The adjustment structure includes:

[0011] A rigid synchronizing rod is horizontally arranged along the width direction of the frame, passes through the front and rear walls of the frame, and is located above the rotating shaft. The cross-sectional shape of the rigid synchronizing rod is rectangular.

[0012] A drive unit, which is mounted on the frame and connected to the rigid synchronizing rod, is used to drive the rigid synchronizing rod to move horizontally along its axial direction.

[0013] Two motion conversion components are respectively disposed at the front end and rear end of the rotating shaft; each motion conversion component includes an inclined guide portion fixedly connected to the rigid synchronizing rod, and a receiving portion fixedly connected to the end of the rotating shaft; the receiving portion is provided with a guide surface that slides with the inclined guide portion, and the extension direction of the guide surface forms an acute angle with the horizontal plane.

[0014] When the drive unit drives the rigid synchronizing rod to move horizontally, the inclined guide part moves accordingly, and through sliding cooperation with the guide surfaces of the front and rear receiving parts, it forces the two ends of the rotating shaft to move vertically by an equal amount, so as to adjust the gap of the printing rollers.

[0015] Preferably, the inclined guide portion is a second slide rail fixed to the side wall of the rigid synchronizing rod; the receiving portion includes a rotating seat fixed to the end of the rotating shaft and a second support plate fixed to the upper wall of the rotating seat; the guide surface is a second slider disposed on the side of the second support plate facing the rigid synchronizing rod, and the second slider slides in cooperation with the second slide rail.

[0016] Preferably, the length direction of the second slider, i.e. the extension direction of the guide surface, makes an angle of 10 degrees with the horizontal plane.

[0017] Preferably, each of the motion conversion components further includes a vertical guide component, the vertical guide component comprising:

[0018] A mounting base, which is fixed to the outer wall of the frame;

[0019] There are two side connecting plates, which are fixed to the left and right sides of the outer peripheral wall of the rotating seat respectively;

[0020] A guide sleeve is fixed to the end of the side connecting plate away from the rotating seat, and its axis is perpendicular to the horizontal plane;

[0021] The guide post has its lower end fixedly connected to the fixed base, and its upper end slidably inserted into the inner wall of the guide sleeve.

[0022] Preferably, a diagonal brace is provided between the lower wall of the fixed base and the outer wall of the frame to enhance the support rigidity.

[0023] Preferably, the driving unit includes:

[0024] A servo motor, which is fixed to the front wall of the frame via an electrode base;

[0025] A gear, which is fixed to the output shaft end of the servo motor;

[0026] The rigid synchronizing rod has multiple sets of teeth arranged sequentially along its length on its upper wall near the front end, and the gear meshes with the multiple sets of teeth.

[0027] Preferably, the drive unit further includes a worm gear mechanism, wherein the worm of the worm gear mechanism is driven by the servo motor, and the worm gear meshes with the teeth on the rigid synchronizing rod.

[0028] Preferably, the rigid synchronizing rod is slidably connected to the frame via a horizontal guide assembly;

[0029] Preferably, the horizontal guide assembly includes a first support plate fixed to the outer wall of the frame, and a first slider fixed to the first support plate;

[0030] Preferably, the rigid synchronizing rod is fixed with a first slide rail on the side facing the first support plate, and the first slide rail is slidably engaged with the first slider.

[0031] Preferably, the rotating seat is rotatably connected to the outer wall of the rotating shaft via a bearing.

[0032] Preferably, the moving direction of the rigid synchronizing rod, the moving direction of the rotating shaft, and the extending direction of the guide surface are all perpendicular to each other.

[0033] This invention provides a carton printing apparatus with adjustable printing roller gap. It has the following beneficial effects:

[0034] 1. Compared with existing technologies, this carton printing device with adjustable printing roller gap introduces a rigid synchronizing rod as a single drive source, coupled with inclined conversion components on both sides that are linked to the ends of the printing rollers. This mechanical structure forcibly ensures the absolute synchronicity of the lifting and lowering movements of the printing rollers. This design fundamentally eliminates the electronic synchronization errors and mechanical response differences caused by the use of two independent drive units in existing technologies. It ensures uniform distribution of printing pressure along the roller body direction, effectively solving quality problems such as dot gain, uneven ink color, and crushing of corrugated cardboard caused by this, and significantly improving the stability and consistency of printing quality.

[0035] 2. Compared with existing technologies, this carton printing device with adjustable printing roller gap utilizes its low friction and high rigidity characteristics to accurately and sensitively convert the minute horizontal displacement of a single drive source into the vertical fine-tuning required by the printing roller. This design not only improves the resolution and repeatability of gap adjustment, but also features a high-rigidity transmission chain with no flexible links, effectively resisting vibrations generated during high-speed printing. Long-term operation is less prone to backlash and wear accumulation, thus achieving precise adjustment while significantly enhancing the reliability and service life of the equipment and reducing maintenance requirements. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the present invention;

[0037] Figure 2 For the present invention Figure 1 A magnified view of a section at point A in the middle;

[0038] Figure 3 This is a schematic diagram of the servo motor and gear connection structure of the present invention;

[0039] Figure 4 This is a schematic diagram of the connection structure between the second support plate and the second slide rail of the present invention;

[0040] Figure 5 This is a partial schematic diagram of the connection structure between the rigid synchronizing rod and the second slider of the present invention.

[0041] The components include: 1. Frame; 101. Oblong hole; 2. Rotating shaft; 3. Rotating seat; 4. Side connecting plate; 5. Guide sleeve; 6. Fixed seat; 7. Diagonal brace; 8. Guide column; 9. Electrode base; 10. Servo motor; 11. First support plate; 12. Second support plate; 13. First slider; 14. First slide rail; 15. Rigid synchronizing rod; 1501. Tooth; 16. Gear; 17. Second slide rail; 18. Second slider. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example:

[0044] like Figures 1 to 5 As shown, an embodiment of the present invention provides a carton printing apparatus with adjustable printing roller gap.

[0045] To achieve stable mounting and guidance of the printing roller on the frame, this device includes a frame 1, with elongated holes 101 on both its front and rear walls. A rotating shaft 2 is slidably connected to the inner walls of the two sets of elongated holes 101, with its front and rear ends extending towards the front and rear sides of the frame 1, respectively. The outer wall of the rotating shaft 2 is used to mount the printing roller. Through this structure, the rotating shaft 2 and the printing roller on it are constrained within the elongated holes 101, thereby enabling smooth vertical movement to adjust the printing pressure while ensuring its fixed horizontal position.

[0046] To address the fundamental problems of asynchronous adjustment and uneven printing pressure at both ends of the printing roller caused by the use of two independent drive units in existing technologies, this device incorporates an adjustment structure. The core of this structure includes a rigid synchronizing rod 15, horizontally positioned along the width of the frame 1, penetrating both the front and rear walls of the frame 1, and located above the rotating shaft 2. The rigid synchronizing rod 15 has a rectangular cross-section. A drive unit is mounted on the frame 1 and connected to the rigid synchronizing rod 15, driving it to move horizontally along its axial direction. Two motion conversion components are respectively positioned at the front and rear ends of the rotating shaft 2. Through this structure, the displacement of the rigid synchronizing rod 15 driven by a single drive unit is simultaneously and indiscriminately transmitted to both sides of the equipment without difference or delay through the rigid rod itself. This physically ensures absolute synchronization of the movements, laying the mechanical foundation for equal lifting and lowering of both ends of the printing roller.

[0047] To reliably convert the precise horizontal displacement of the rigid synchronizing rod 15 into the vertical displacement required by the printing roller, and to ensure the stability and high precision of the motion process, each motion conversion component includes an inclined guide portion fixedly connected to the rigid synchronizing rod 15, and a receiving portion fixedly connected to the end of the rotating shaft 2. The receiving portion has a guide surface that slides in conjunction with the inclined guide portion, and the extension direction of the guide surface forms an acute angle with the horizontal plane. Specifically, the inclined guide portion is a second slide rail 17 fixed to the side wall of the rigid synchronizing rod 15; the receiving portion includes a rotating seat 3 fixed to the end of the rotating shaft 2, and a second support plate 12 fixed to the upper wall of the rotating seat 3; the guide surface is a second slider 18 disposed on the side of the second support plate 12 facing the rigid synchronizing rod 15, and the second slider 18 slides in conjunction with the second slide rail 17. The length direction of the second slider 18, i.e., the extension direction of the guide surface, forms an angle of 10 degrees with the horizontal plane. When the rigid synchronizing rod 15 moves horizontally, the second slide rail 17 moves accordingly, forcing the second slider 18 to slide relative to its inclined plane, thereby accurately decomposing the horizontal driving force and driving the rotating seat 3, rotating shaft 2 and printing roller to move vertically, realizing a reliable conversion from coarse adjustment to fine micron-level displacement.

[0048] To further constrain the vertical movement trajectory of the printing roller, eliminate any possible lateral swaying or deflection, and ensure absolute parallelism and stability of the printing pressure, each motion conversion component also includes a vertical guide component. The vertical guide component includes a fixed base 6 fixed to the outer wall of the frame 1; two side connecting plates 4, fixed to the left and right sides of the outer peripheral wall of the rotating seat 3 respectively; a guide sleeve 5 fixed to the end of the side connecting plate 4 away from the rotating seat 3, with its axis perpendicular to the horizontal plane; and a guide post 8, its lower end fixedly connected to the fixed base 6, and its upper end slidably inserted into the inner wall of the guide sleeve 5. Furthermore, a diagonal brace 7 is provided between the lower wall of the fixed base 6 and the outer wall of the frame 1 to enhance support rigidity. Through this structure, the up-and-down movement of the rotating seat 3 is strictly limited in the vertical direction by the precision sliding pair formed by the guide post 8 and the guide sleeve 5, forming a highly rigid motion frame that effectively resists vibration and lateral forces during the printing process, ensuring the long-term stability of the printing roller's posture after adjustment.

[0049] To achieve precise digital setting and position locking of the printing roller gap, and to prevent changes in the adjusted gap due to vibration or external force, the drive unit of this device includes a servo motor 10 fixed to the front wall of the frame 1 via an electrode base 9, and a gear 16 fixed to the output shaft end of the servo motor 10. Multiple sets of teeth 1501 are arranged sequentially along the length of the upper wall of the rigid synchronizing rod 15 near its front end, and the gear 16 meshes with these teeth 1501. The drive unit may also include a worm gear mechanism, where the worm is driven by the servo motor 10, and the worm gear meshes with the teeth 1501 on the rigid synchronizing rod 15. Through this structure, the servo motor 10 can receive control signals for precise angular displacement control, and convert this into precise linear displacement of the rigid synchronizing rod 15 via a rack and pinion or worm gear pair. The introduction of the worm gear mechanism provides reliable mechanical self-locking capability, ensuring that the gap position of the printing roller is firmly locked and does not drift after the servo motor 10 is powered off.

[0050] To ensure the straightness and smoothness of the rigid synchronizing rod 15 during long-stroke horizontal movement and to prevent jamming or deviation, the rigid synchronizing rod 15 is slidably connected to the frame 1 via a horizontal guide assembly. The horizontal guide assembly includes a first support plate 11 fixed to the outer wall of the frame 1 and a first slider 13 fixed to the first support plate 11. A first slide rail 14 is fixed to the side of the rigid synchronizing rod 15 facing the first support plate 11, and the first slide rail 14 and the first slider 13 are slidably engaged. Through this structure, the entire movement of the rigid synchronizing rod 15 is guided and supported by the precise first slide rail 14 and first slider 13 pair, greatly reducing sliding friction resistance, ensuring efficient transmission of driving force and accurate displacement, while also improving the rigidity and service life of the entire drive chain.

[0051] To accommodate the rotational movement of the printing roller during the printing process without interfering with its vertical adjustment function, the rotating base 3 is rotatably connected to the outer wall of the rotating shaft 2 via bearings. With this structure, the rotating shaft 2 and the printing roller mounted on it can rotate freely to perform printing operations, while its vertical lifting and lowering adjustment function is independently controlled by guide and drive components fixedly connected to the rotating base 3. This decoupling of rotational and adjustment movements ensures that the two movements do not interfere with each other.

[0052] To ensure the purity and efficiency of motion conversion and avoid motion interference and energy loss, in this device, the moving directions of the rigid synchronizing rod 15, the moving direction of the rotating shaft 2, and the extending direction of the guide surface (i.e., the length direction of the second slider 18) are designed to be mutually perpendicular. Through the above orthogonal spatial motion relationship, the transmission path of the driving force is clear, the horizontal driving force is converted into an effective vertical lifting force to the maximum extent, the mechanical efficiency of the kinematic chain is optimized, and the stress distribution inside the system is more reasonable.

[0053] Working principle

[0054] The working principle of this invention is as follows: When it is necessary to adjust the gap between the printing roller and another roller (such as an anilox roller or an impression roller), the control system sends a command to the servo motor 10. The servo motor 10 drives the rigid synchronizing rod 15 to move precisely horizontally along its axial direction via the gear 16 (or via a worm gear mechanism). Since the rigid synchronizing rod 15 is a single rod that runs through the front and rear of the frame, the displacement at one end is rigidly and synchronously transmitted to the other end through the rod body, thereby ensuring that the displacement at both ends remains consistent at all times.

[0055] The horizontal movement of the rigid synchronizing rod 15 drives the second slide rails 17 fixed on both sides to move synchronously. The second slide rails 17 then slide relative to the second slider 18 mounted on the second support plate 12. Since the length direction of the second slider 18 forms a 10-degree angle with the horizontal plane, the horizontal movement of the second slide rail 17 is forcibly decomposed. The vertical component of the force of the second slider 18 sliding on the inclined plane pushes the second support plate 12, the rotating seat 3, and the rotating shaft 2 connected to it to make a strict up-and-down linear movement along the vertical guide path formed by the guide post 8 and the guide sleeve 5. Since the two sets of motion conversion components are driven by the same rigid synchronizing rod 15 and have a symmetrical structure, the front and rear ends of the rotating shaft 2 are forcibly raised or lowered synchronously, realizing precise and parallel adjustment of the printing roller gap.

[0056] Throughout the process, the first slide rail 14 and the first slider 13 ensure smooth and stable movement of the rigid synchronizing rod 15 without swaying; the guide column 8 and the guide sleeve 5 ensure stable lifting and lowering of the rotating shaft 2 without shaking; the worm gear mechanism (if equipped) can achieve mechanical self-locking after adjustment to prevent changes in clearance due to external forces. This design eliminates the asynchrony problem easily caused by traditional dual-sided independent drives from a mechanical principle perspective, thereby obtaining uniform and stable printing pressure, improving printing quality and equipment reliability.

[0057] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A carton printing apparatus with adjustable printing roller gap, characterized in that, include: The frame (1) has elongated holes (101) on its front and rear walls. A rotating shaft (2) is slidably connected to the inner wall of the two sets of elongated holes (101), and the front and rear ends of the rotating shaft (2) extend toward the front and rear sides of the frame (1) respectively. The outer wall of the rotating shaft (2) is used to set the printing roller. An adjustment structure is provided between the end of the rotating shaft (2) extending to the outer wall of the frame (1) and the frame (1); The adjustment structure includes: A rigid synchronizing rod (15) is horizontally arranged along the width direction of the frame (1) and passes through the front and rear walls of the frame (1), and is located above the rotating shaft (2). The cross-sectional shape of the rigid synchronizing rod (15) is rectangular. A drive unit, which is mounted on the frame (1) and connected to the rigid synchronizing rod (15), is used to drive the rigid synchronizing rod (15) to move horizontally along its axial direction; Two motion conversion components are respectively disposed at the front end and rear end of the rotating shaft (2); each motion conversion component includes an inclined guide portion fixedly connected to the rigid synchronizing rod (15) and a receiving portion fixedly connected to the end of the rotating shaft (2); the receiving portion is provided with a guide surface that slides with the inclined guide portion, and the extension direction of the guide surface forms an acute angle with the horizontal plane; When the drive unit drives the rigid synchronizing rod (15) to move horizontally, the inclined guide part moves accordingly, and through sliding cooperation with the guide surfaces of the front and rear receiving parts, it forces the two ends of the rotating shaft (2) to move vertically in equal amounts to adjust the printing roller gap.

2. The apparatus according to claim 1, characterized in that: The inclined guide portion is a second slide rail (17) fixed to the side wall of the rigid synchronizing rod (15); the receiving portion includes a rotating seat (3) fixed to the end of the rotating shaft (2) and a second support plate (12) fixed to the upper wall of the rotating seat (3); the guide surface is a second slider (18) disposed on the side of the second support plate (12) facing the rigid synchronizing rod (15), and the second slider (18) slides in cooperation with the second slide rail (17).

3. The apparatus according to claim 2, characterized in that: The length direction of the second slider (18), that is, the extension direction of the guide surface, has an angle of 10 degrees with the horizontal plane.

4. The apparatus according to claim 3, characterized in that: Each of the motion conversion components further includes a vertical guide component, the vertical guide component comprising: A mounting base (6) is fixed to the outer wall of the frame (1); Two side connecting plates (4) are fixed to the left and right sides of the outer peripheral wall of the rotating seat (3), respectively. The guide sleeve (5) is fixed to one end of the side connecting plate (4) away from the rotating seat (3), and its axis is perpendicular to the horizontal plane; The guide post (8) is fixedly connected at its lower end to the fixed seat (6) and slidably inserted at its upper end into the inner wall of the guide sleeve (5).

5. The apparatus according to claim 4, characterized in that: A diagonal brace (7) for enhancing support rigidity is provided between the lower wall of the fixed base (6) and the outer wall of the frame (1).

6. The apparatus according to claim 1, characterized in that: The driving unit includes: A servo motor (10) is fixed to the front wall of the frame (1) via an electrode base (9); Gear (16), which is fixed to the output shaft end of the servo motor (10); The rigid synchronizing rod (15) has multiple sets of teeth (1501) arranged sequentially along its length on the upper wall near the front end, and the gear (16) meshes with the multiple sets of teeth (1501).

7. The apparatus according to claim 6, characterized in that: The drive unit also includes a worm gear mechanism, the worm of which is driven by the servo motor (10), and the worm gear meshes with the teeth (1501) on the rigid synchronizing rod (15).

8. The apparatus according to claim 1, characterized in that: The rigid synchronizing rod (15) is slidably connected to the frame (1) through a horizontal guide assembly; The horizontal guide assembly includes a first support plate (11) fixed to the outer wall of the frame (1) and a first slider (13) fixed to the first support plate (11). The rigid synchronizing rod (15) is fixed with a first slide rail (14) on the side facing the first support plate (11), and the first slide rail (14) slides in cooperation with the first slider (13).

9. The apparatus according to claim 2, characterized in that: The rotating seat (3) is rotatably connected to the outer wall of the rotating shaft (2) via a bearing.

10. The apparatus according to claim 1, characterized in that: The moving direction of the rigid synchronizing rod (15), the moving direction of the rotating shaft (2), and the extending direction of the guide surface are all perpendicular to each other.

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