A printing mechanism of a flexographic printing machine

Abstract

The utility model relates to the field of flexographic printing press, especially a printing mechanism of flexographic printing press. Its including mounting bracket and the edition roller and the bottom roller of rotation setting on mounting bracket, the bottom roller seat is rotatably connected on the bottom roller, the bottom roller seat is slidably arranged on the mounting bracket, still include the compression assembly under the bottom roller seat, the compression assembly includes drive structure, wedge and fixed block, the fixed block is connected on the bottom roller seat, the surface on fixed block close wedge is formed with the inclined setting guide surface, the inclined surface of wedge and the guide surface slide and resist, drive structure is used for driving wedge to slide, and wedge pushes fixed block, to drive the bottom roller seat and the bottom roller move to the direction close to edition roller, drive structure includes drive motor and lead screw, drive motor is used for driving lead screw rotation, wedge is threadedly connected on the lead screw, still include guide structure, guide structure is used for guiding the sliding of bottom roller seat, still include guide structure, guide structure is used for guiding the sliding of wedge.

Description

Technical Field

[0001] This utility model relates to the field of flexographic printing machines, and in particular to a printing mechanism for a flexographic printing machine. Background Technology

[0002] A flexographic printing press is a letterpress printing device that uses flexible printing plates. Ink is transferred from the printing plate to the substrate via an anilox roller. A typical flexographic printing press consists of an unloading unit, a tension control unit, a traction feeding unit, a printing unit, a drying unit, and a rewinding unit. The basic printing process is as follows: the substrate is released from the unloading unit, passes through tension control and traction feeding, and then enters the printing unit. Each color group is printed sequentially, and after drying, it is rewound by the rewinding unit.

[0003] In flexographic printing presses, the printing mechanism includes a rotating base roller and plate roller, as well as a clamping mechanism. The clamping mechanism is one of the core components ensuring print quality. It is used to press the base roller and plate roller together, keeping the substrate stable at the printing contact surface and preventing slippage of the substrate from affecting registration accuracy and print quality. Most existing flexographic printing presses use cylinders as the drive source for their clamping mechanisms. The cylinders push the pressure roller or swing arm to achieve the pressing and separation between the base roller and plate roller.

[0004] However, using cylinders as the drive source for the clamping mechanism has many shortcomings in practical applications. The working pressure of the cylinder depends on the external air supply. When the air supply pressure fluctuates, the cylinder output force changes accordingly, resulting in uneven clamping force and affecting the registration accuracy. For large-diameter, heavy printing rollers, if a small-diameter cylinder is used, the output force is insufficient to overcome the combined force of the roller's weight and the clamping force. If a large-diameter cylinder is used, although the output force increases, the installation space required increases significantly, and installation may even be impossible due to space constraints. In addition, there is a delay in cylinder action, and it is difficult to ensure complete synchronization when multiple cylinders work together. Furthermore, after long-term use, the cylinders are in a state of fatigue, and the output accuracy and support stability gradually decrease. The attenuation of clamping force is difficult to compensate for by simple means. Utility Model Content

[0005] To address the aforementioned problems, this invention provides a printing mechanism for a flexographic printing machine, aiming to offer a driving solution that provides stable pressure, adjustable output force, and does not significantly increase space occupancy.

[0006] The printing mechanism of the flexographic printing machine provided by this utility model adopts the following technical solution: A printing mechanism for a flexographic printing machine includes a mounting frame and a plate roller and a bottom roller rotatably mounted on the mounting frame. The plate roller is used to transfer images onto a substrate. The bottom roller is located below the plate roller and supports the substrate. An impression gap is formed between the plate roller and the bottom roller for the substrate to pass through. A bottom roller seat is rotatably connected to the bottom roller and is slidably mounted on the mounting frame. The machine also includes a clamping assembly located below the bottom roller seat. The clamping assembly is used to clamp the bottom roller and the plate roller together. The clamping assembly includes a drive structure, a wedge block, and a fixing block. The fixing block is connected to the bottom roller seat. The fixed block has an inclined guide surface on its surface near the wedge block. The inclined surface of the wedge block slides against the guide surface. The driving structure is used to drive the wedge block to slide. The wedge block pushes against the fixed block to drive the bottom roller seat and the bottom roller to move towards the printing roller. The driving structure includes a drive motor and a lead screw. The drive motor is used to drive the lead screw to rotate. The wedge block is threadedly connected to the lead screw. The structure also includes a guide structure for guiding the sliding of the bottom roller seat. The structure further includes a guide structure for guiding the sliding of the wedge block.

[0007] By adopting the above technical solution, when the drive structure drives the wedge block to slide, the wedge block pushes against the fixed block through the cooperation of the inclined surface and the guide surface, driving the bottom roller seat and the bottom roller to move closer to the printing roller. At the same time, the guide structure guides the sliding of the bottom roller seat. The inclined surface cooperation between the wedge block and the guide surface can convert the horizontal thrust generated by the drive structure into a vertical pushing force. Furthermore, utilizing the self-locking characteristic of the inclined surface, the wedge block can remain in any position after the drive structure stops applying force, maintaining the clamping force between the bottom roller and the printing roller without continuous energy consumption. This solves the problem of the cylinder requiring continuous air supply and the instability of pressure caused by air source fluctuations. Simultaneously, the guide structure ensures the directional accuracy of the bottom roller seat during the lifting process, ensuring a uniform and consistent printing gap between the bottom roller and the printing roller. The screw drive has extremely high transmission accuracy and self-locking characteristics, enabling precise control of the wedge block's position, thereby precisely controlling the clamping force between the bottom roller and the printing roller. Moreover, the motor drive does not rely on an external air source, ensuring stable and controllable pressure unaffected by air source fluctuations. The guide structure ensures the wedge block's accurate direction during sliding, preventing skew.

[0008] Optionally, a clamping cylinder may also be included, which is used to drive the bottom roller seat to slide so that the fixed block is pressed against the wedge block.

[0009] By adopting the above technical solution, during the high-speed operation of the printing equipment, the printing roller and the bottom roller are subjected to continuous dynamic loads. Although the inclined surface cooperation between the wedge block and the fixed block can provide stable clamping force, the vibration generated by high-speed rotation may still cause slight up-and-down movement of the bottom roller seat, affecting the stability of the impression gap. After the wedge block is in position, the clamping cylinder continuously applies thrust, keeping the fixed block pressed firmly against the inclined surface of the wedge block. This eliminates the slight gap that may be caused by vibration between the fixed block and the wedge block, ensuring that the bottom roller seat maintains a stable force state in the vertical direction. This effectively suppresses the vibration generated by the bottom roller during high-speed operation, ensures the uniformity of the impression gap, and thus improves the printing registration accuracy and image clarity.

[0010] Optionally, the clamping cylinder is located below the bottom roller seat, and the clamping cylinder is used to pull the bottom roller seat down.

[0011] By adopting the above technical solution, the clamping cylinder is arranged below the bottom roller seat, so that it is in the same horizontal area as the clamping components such as the wedge block and the fixing block. This makes the overall layout of the clamping components more compact and is conducive to the spatial optimization of the printing unit in the width direction.

[0012] Optionally, the drive structure further includes pulleys and a timing belt. There are at least two pulleys. The drive motor is used to drive one of the pulleys to rotate. One of the pulleys is coaxially arranged and fixedly connected to the lead screw. The timing belt is wound around the pulley.

[0013] By adopting the above technical solution, when the installation position of the drive motor and the lead screw cannot be directly coaxially connected due to space limitations, the combination of pulley and synchronous belt realizes long-distance power transmission, allowing the drive motor to be arranged in any suitable position on the mounting frame, making full use of the equipment space and avoiding the impact on the overall layout due to motor size limitations.

[0014] Optionally, the guide structure includes a guide block and a guide rail. The guide block is connected to the wedge block, and a guide groove is provided on the guide block for the guide rail to pass through. The guide rail is mounted on the mounting bracket.

[0015] By adopting the above technical solution, the sliding fit between the guide block and the guide rail precisely constrains the movement direction of the wedge block, ensuring that the wedge block slides in a straight line without deflection or shaking, thereby ensuring that the inclined surface of the wedge block always maintains the correct fit with the guide surface of the fixed block.

[0016] Optionally, the lead screw is a ball screw.

[0017] By adopting the above technical solution, the ball screw incorporates balls between the screw and the nut, transforming sliding friction into rolling friction. This results in higher transmission efficiency than ordinary sliding screws, allowing the drive motor to operate with less power to move the wedge block. Furthermore, the ball screw exhibits low frictional resistance and minimal wear, maintains good precision over long-term use, and possesses higher positioning accuracy and repeatability. It can precisely control the clamping force between the bottom roller and the printing roller, making it suitable for printing applications requiring frequent adjustments to the clamping force.

[0018] Optionally, the guide structure includes a slider and a slide rail. The slider is connected to the bottom roller seat, and a groove is provided on the slider for the slide rail to pass through. The slide rail is mounted on the mounting frame.

[0019] By adopting the above technical solution, the sliding cooperation between the slider and the slide rail precisely guides the lifting and lowering movement of the bottom roller seat, ensuring that the bottom roller seat always moves in the vertical direction and will not wobble in the front-back or left-right directions, ensuring the parallelism between the bottom roller and the printing roller, thereby ensuring that the substrate is subjected to uniform force in the printing gap and the printing is clear.

[0020] Optionally, it also includes an anilox roller rotatably mounted on a mounting frame, the anilox roller being located above the printing roller and used to transfer ink to the printing roller, an anilox roller seat being rotatably connected to the anilox roller, the anilox roller seat being slidably mounted on the mounting frame, and a pressing assembly located below the anilox roller seat, the pressing assembly being used to press the anilox roller and the printing roller together, the pressing assembly having the same structure as the pressing assembly.

[0021] By adopting the above technical solution, the anilox roller is responsible for transferring ink to the printing roller, and the clamping force between the anilox roller and the printing roller directly affects the uniformity of ink transfer and printing quality. By setting a pressing component with the same structure between the anilox roller and the printing roller, the clamping force between the anilox roller and the printing roller can also be independently and precisely controlled, and it also has the advantages of stable pressure, adjustable output force, and no dependence on air source, thus realizing the comprehensive optimization of the key clamping relationship in the printing mechanism. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model.

[0023] Figure 2 yes Figure 1 Enlarged view of point A in the middle.

[0024] Explanation of reference numerals in the attached drawings: 1. Mounting frame; 2. Printing roller; 3. Bottom roller; 4. Bottom roller seat; 5. Pressing assembly; 51. Drive structure; 511. Drive motor; 512. Lead screw; 513. Pulley; 514. Synchronous belt; 52. Wedge block; 53. Fixing block; 531. Guide surface; 6. Guide structure; 61. Slider; 62. Slide rail; 7. Pressing cylinder; 8. Guide structure; 81. Guide block; 82. Guide rail; 9. Anilox roller; 100. Anilox roller seat; 110. Pressing assembly. Detailed Implementation

[0025] The following combination Figures 1-2 The present invention will be described in further detail below.

[0026] This utility model discloses a printing mechanism for a flexographic printing machine. (Refer to...) Figure 1 The printing mechanism of the flexographic printing press includes a mounting frame 1 and a plate roller 2 and a bottom roller 3 rotatably mounted on the mounting frame 1. The plate roller 2 is used to transfer the image onto the substrate. The bottom roller 3 is located below the plate roller 2 and is used to support the substrate. An impression gap is formed between the plate roller 2 and the bottom roller 3 for the substrate to pass through. A bottom roller seat 4 is rotatably connected to the bottom roller 3, and the bottom roller seat 4 is slidably mounted on the mounting frame 1 in the vertical direction.

[0027] Reference Figure 1 The mounting frame 1 can be made of cast iron or welded steel plate, possessing sufficient rigidity and vibration resistance. The printing roller 2 is a cylindrical roller body covered with a flexible printing plate, and can be made of aluminum alloy or steel core. The bottom roller 3 is a support roller, which can be made of steel roller body, and its surface can be covered with a rubber layer to increase the friction between it and the substrate. The bottom roller seat 4 can be made of cast iron or steel and is rotatably connected to the bottom roller 3 via bearings.

[0028] Reference Figure 1 and Figure 2 The printing mechanism also includes a clamping assembly 5 located below the bottom roller seat 4. The clamping assembly 5 is used to clamp the bottom roller 3 and the printing plate roller 2. The clamping assembly 5 includes a drive structure 51, a wedge block 52, and a fixing block 53. The fixing block 53 is fixedly connected to the bottom roller seat 4 by a bolt assembly, and an inclined guide surface 531 is formed on the surface of the fixing block 53 near the wedge block 52. The inclined surface of the wedge block 52 slides against the guide surface 531. The drive structure 51 is used to drive the wedge block 52 to slide, and the wedge block 52 pushes the fixing block 53 to drive the bottom roller seat 4 and the bottom roller 3 to move closer to the printing plate roller 2. The wedge block 52 and the fixing block 53 can be made of steel, and the angle between the guide surface 531 and the horizontal plane is preferably 20° to 45° to ensure sufficient vertical pushing force and good self-locking effect. In other embodiments, the inclined surfaces of the wedge block 52 and the fixed block 53 may also be provided with rolling elements (such as rollers or balls) to reduce sliding friction and make the sliding of the wedge block 52 smoother.

[0029] Reference Figure 2 The drive structure 51 includes a drive motor 511 and a lead screw 512. The drive motor 511 drives the lead screw 512 to rotate, and a wedge block 52 is threadedly connected to the lead screw 512. The drive motor 511 is preferably a stepper motor or a servo motor, which can achieve precise angle control. The lead screw 512 can be a trapezoidal lead screw or a ball screw; in this embodiment, a ball screw is preferred.

[0030] Reference Figure 2 The drive structure 51 also includes a guide structure 8, which guides the sliding of the wedge block 52. The guide structure 8 includes a guide block 81 and a guide rail 82. The guide block 81 is fixedly connected to the wedge block 52 by a bolt assembly, and a guide groove is provided on the guide block 81 for the guide rail 82 to pass through. The guide rail 82 is fixed to the mounting bracket 1 by a bolt assembly. In other embodiments, the guide structure 8 may also use other forms of linear guide mechanisms instead of the cooperation between the guide block 81 and the guide rail 82. For example, the guide structure 8 may use a guide post and guide sleeve cooperation method.

[0031] Reference Figure 2 The drive structure 51 also includes pulleys 513 and a synchronous belt 514. At least two pulleys 513 are provided. The drive motor 511 drives one of the pulleys 513 to rotate. One pulley 513 is coaxially arranged and fixedly connected to the lead screw 512. The synchronous belt 514 is wound around the pulley 513. In this embodiment, the two pulleys 513 are a large pulley and a small pulley, respectively. The drive motor 511 drives the small pulley to rotate, and the small pulley drives the large pulley to rotate through the synchronous belt 514. The large pulley is fixedly connected to the lead screw 512, thereby achieving speed reduction and torque increase. In other embodiments, the drive motor 511 can be arranged coaxially with the lead screw 512. In this case, the pulleys 513 and the synchronous belt 514 can be omitted, and the output shaft of the drive motor 511 can be directly connected to the lead screw 512 through a coupling. In other embodiments, the drive structure 51 can also use a worm gear reducer to drive the lead screw 512 to rotate, thereby obtaining a larger reduction ratio and output torque. In other embodiments, the drive structure 51 may also employ other forms of linear drive mechanisms instead of the lead screw and nut mechanism. For example, the drive structure 51 may be an electric or hydraulic cylinder or a linear motor.

[0032] Reference Figure 2 The printing mechanism also includes a guide structure 6, which guides the sliding of the bottom roller seat 4. The guide structure 6 includes a slider 61 and a slide rail 62. The slider 61 is fixedly connected to the bottom roller seat 4 by a bolt assembly, and a groove is provided on the slider 61 for the slide rail 62 to pass through. The slide rail 62 is fixed to the mounting bracket 1 by a bolt assembly. Two sets of guide structures 6 are provided, located on both sides of the bottom roller seat 4 respectively, to ensure the parallelism of the bottom roller seat 4 during lifting and lowering. In other embodiments, the guide structure 6 may also adopt a guide post and guide sleeve structure.

[0033] Reference Figure 2 The printing mechanism also includes a clamping cylinder 7. The clamping cylinder 7 drives the bottom roller seat 4 to slide, causing the fixing block 53 to press against the wedge block 52. The clamping cylinder 7 is located below the bottom roller seat 4 and is used to pull the bottom roller seat 4 downwards. The cylinder body of the clamping cylinder 7 is fixed to the mounting bracket 1, and its piston rod is connected to the bottom roller seat 4 via a connector. When the wedge block 52 is in position, the clamping cylinder 7 applies a pulling force to pull the bottom roller seat 4 downwards, ensuring that the guide surface 531 of the fixing block 53 and the inclined surface of the wedge block 52 remain in close contact. The working air pressure of the clamping cylinder 7 is adjustable to adjust the clamping force. In other embodiments, the clamping cylinder 7 may also be a spring-return cylinder or a double-acting cylinder.

[0034] Reference Figure 1 The printing mechanism also includes an anilox roller 9 rotatably mounted on the mounting frame 1. The anilox roller 9 is located above the printing plate 2 and is used to transfer ink to the printing plate 2. An anilox roller seat 100 is rotatably connected to the anilox roller 9 and is slidably mounted on the mounting frame 1. The printing mechanism also includes a pressing assembly 110 located below the anilox roller seat 100. The pressing assembly 110 is used to press the anilox roller 9 and the printing plate 2 together. The structure of the pressing assembly 110 is the same as that of the pressing assembly 5.

[0035] Reference Figure 1 The pressing assembly 110 also includes a drive structure 51, a wedge block 52 and a fixing block 53, a pressing cylinder 7 and a guide structure 8. The mating relationship between the anilox roller seat 100 and the pressing assembly 110 is the same as the mating relationship between the bottom roller seat 4 and the pressing assembly 5. The guide structure 8 is also applicable to the wedge block 52 in the pressing assembly 110, which will not be described in detail here.

[0036] The printing mechanism of this flexographic printing machine operates on the following principle: During printing, the substrate passes through the printing gap between the bottom roller 3 and the plate roller 2. When it is necessary to press the bottom roller 3 and the plate roller 2 together, the drive motor 511 drives the lead screw 512 to rotate via the pulley 513 and the synchronous belt 514. The lead screw 512 drives the wedge block 52, which is threadedly connected to it, to slide along the guide rail 82 (horizontal direction). The inclined surface of the wedge block 52 slides against the guide surface 531 of the fixed block 53. As the wedge block 52 slides, the inclined surface of the wedge block 52 gradually pushes the fixed block 53 upward. The fixed block 53 drives the bottom roller seat 4 to slide vertically upward along the slide rail 62 of the guide structure 6. The bottom roller seat 4 drives the bottom roller 3 to move upward, reducing the printing gap between the bottom roller 3 and the plate roller 2 until the required pressing force is achieved. After the wedge block 52 moves into position, the drive motor 511 stops rotating. Then, the pressing cylinder 7 is ventilated, pulling the bottom roller seat 4 downwards, ensuring that the guide surface 531 of the fixed block 53 and the inclined surface of the wedge block 52 remain in close contact, eliminating any minor gaps that may be caused by vibration. The pressing and separating actions between the anilox roller 9 and the printing roller 2 operate on the same principle.

[0037] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A printing mechanism for a flexographic printing machine, characterized in that: The assembly includes a mounting frame (1) and a printing roller (2) and a bottom roller (3) rotatably mounted on the mounting frame (1). The printing roller (2) is used to transfer images and text onto a substrate. The bottom roller (3) is located below the printing roller (2) and is used to support the substrate. An impression gap is formed between the printing roller (2) and the bottom roller (3) for the substrate to pass through. A bottom roller seat (4) is rotatably connected to the bottom roller (3). The bottom roller seat (4) is slidably mounted on the mounting frame (1). The assembly also includes a pressing component (5) located below the bottom roller seat (4). The pressing component (5) is used to press the bottom roller (3) and the printing roller (2) together. The pressing component (5) includes a drive structure (51), a wedge block (52), and a fixing block (53). The fixing block (53) is connected to the bottom roller seat (4) and is close to the wedge block (51). 2) An inclined guide surface (531) is formed on the surface of the wedge block (52). The inclined surface of the wedge block (52) slides against the guide surface (531). The driving structure (51) is used to drive the wedge block (52) to slide. The wedge block (52) pushes the fixing block (53) to drive the bottom roller seat (4) and the bottom roller (3) to move closer to the printing roller (2). The driving structure (51) includes a driving motor (511) and a lead screw (512). The driving motor (511) is used to drive the lead screw (512) to rotate. The wedge block (52) is threaded onto the lead screw (512). It also includes a guide structure (6) for guiding the sliding of the bottom roller seat (4). It also includes a guide structure (8) for guiding the sliding of the wedge block (52).

2. The printing mechanism of a flexographic printing machine according to claim 1, characterized in that: It also includes a pressing cylinder (7) for driving the bottom roller seat (4) to slide so that the fixing block (53) presses against the wedge block (52).

3. The printing mechanism of a flexographic printing machine according to claim 2, characterized in that: The pressing cylinder (7) is located below the bottom roller seat (4), and the pressing cylinder (7) is used to pull the bottom roller seat (4) down.

4. The printing mechanism of a flexographic printing machine according to claim 1, characterized in that: The drive structure (51) further includes pulleys (513) and a timing belt (514). There are at least two pulleys (513). The drive motor (511) is used to drive one of the pulleys (513) to rotate. One of the pulleys (513) is coaxially arranged and fixedly connected to the lead screw (512). The timing belt (514) is wound around the pulley (513).

5. The printing mechanism of a flexographic printing machine according to claim 1, characterized in that: The guide structure (8) includes a guide block (81) and a guide rail (82). The guide block (81) is connected to the wedge block (52). The guide block (81) has a guide groove for the guide rail (82) to pass through. The guide rail (82) is mounted on the mounting bracket (1).

6. The printing mechanism of a flexographic printing machine according to claim 1, characterized in that: The lead screw (512) is a ball screw.

7. The printing mechanism of a flexographic printing machine according to claim 1, characterized in that: The guide structure (6) includes a slider (61) and a slide rail (62). The slider (61) is connected to the bottom roller seat (4). The slider (61) has a groove for the slide rail (62) to pass through. The slide rail (62) is mounted on the mounting frame (1).

8. The printing mechanism of a flexographic printing machine according to any one of claims 1-7, characterized in that: It also includes an anilox roller (9) rotatably mounted on the mounting frame (1), the anilox roller (9) being located above the printing roller (2) and used to transfer ink to the printing roller (2), an anilox roller seat (100) being rotatably connected to the anilox roller (9), the anilox roller seat (100) being slidably mounted on the mounting frame (1), and a pressing assembly (110) located below the anilox roller seat (100), the pressing assembly (110) being used to press the anilox roller (9) and the printing roller (2), the structure of the pressing assembly (110) being the same as the structure of the pressing assembly (5).

Images