Disc high-speed printer nozzle adjusting device and method for cylindrical product

Abstract

The application belongs to the technical field of printing, and discloses a disc high-speed printer nozzle adjusting device and method for cylindrical products, which comprises a mounting base frame, a nozzle bottom plate, an XZR multi-axis servo driving mechanism, an adaptive pressure compensation module, a multi-nozzle collaborative calibration module and a control module; the mounting base frame is detachably mounted at a printing operation end of a nozzle vehicle, the XZR multi-axis servo driving mechanism is assembled on the mounting base frame and in transmission connection with the nozzle bottom plate, a plurality of printing nozzles with consistent nozzle holes are arranged on the nozzle bottom plate, the control module controls the XZR multi-axis servo driving mechanism to drive the nozzle bottom plate to realize linear displacement adjustment along the X-axis and the Z-axis and angle deflection adjustment around the R-axis parallel to the arrangement direction of the printing nozzles by calling pre-stored adjusting parameters in a built-in parameter mapping database matched with the diameter of a cylindrical product to be printed; and the adaptive pressure compensation module comprises a plurality of pressure compensation units corresponding to the printing nozzles.

Description

Technical Field

[0001] This invention relates to the field of printing technology, specifically to a disc-type high-speed printer nozzle adjustment device and method for cylindrical products. Background Technology

[0002] Printing on the surfaces of specially shaped objects, such as bottles, jars, and pen barrels, is a core process for product identification, decoration, and information transmission in industries such as packaging, electronics, and daily chemicals. Rotary disc printers, with their efficient and continuous operation, have become the mainstream equipment for this process. They use inkjet printheads to complete circumferential printing on the surface of rotating cylindrical products, adapting to the needs of large-scale production.

[0003] However, the curved surface characteristics of cylindrical products present unique challenges to the printing process, and existing printing technologies struggle to meet the requirements of high-precision printing: First, the splicing process lacks precision. Multi-nozzle splicing is the core method for expanding the printing width, but the curved surface of cylindrical products results in differences in the relative distance and spray angle between each nozzle and the product surface. Combined with nozzle installation errors and mechanical transmission gaps, this makes it easy for the printed patterns of adjacent nozzles to exhibit ghosting, gaps, or overlaps, damaging the integrity and continuity of the pattern. Second, the process stability is insufficient. In high-speed printing scenarios, changes in nozzle posture and product rotation acceleration can cause pressure fluctuations in the ink path system. Existing processes have not established a linkage scheme between pressure compensation and curved surface printing, resulting in inconsistent ink output from different nozzles, which in turn produces quality defects such as color difference and broken lines, restricting the improvement of precision and large-scale application of printing technology for cylindrical products. Summary of the Invention

[0004] The purpose of this invention is to provide a printhead adjustment device and method for a high-speed disc printer for cylindrical products, which solves the printing quality problems caused by multi-printhead splicing errors and ink pressure fluctuations, and achieves high-precision and high-stability printing of cylindrical products of different diameters.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A disc-type high-speed printer nozzle adjustment device for cylindrical products includes a mounting base, a nozzle base plate, an XZR multi-axis servo drive mechanism, an adaptive pressure compensation module, a multi-nozzle collaborative calibration module, and a control module. The mounting base is detachably mounted on the printing end of the printhead carriage. The XZR multi-axis servo drive mechanism is mounted on the mounting base and is connected to the printhead base plate. Several printheads with the same nozzle orientation are spaced apart on the printhead base plate. The control module controls the XZR multi-axis servo drive mechanism to drive the printhead base plate to achieve linear displacement adjustment along the X-axis and Z-axis, and angle deflection adjustment around the R-axis parallel to the printhead arrangement direction by calling the pre-stored adjustment parameters in the built-in parameter mapping database that match the diameter of the cylindrical product to be printed. The adaptive pressure compensation module includes several pressure compensation units corresponding to each printhead. The pressure output terminal of each pressure compensation unit is connected to the ink path channel of its corresponding printhead, and the ink path pressure is dynamically stabilized by the control module. The multi-nozzle collaborative calibration module includes a laser positioner, an industrial camera, a spot position sensor, an image analysis unit, and a calibration execution unit. The laser positioner comprises several groups corresponding to the printheads, with each group collinear with the central axis of the corresponding printhead nozzle and emitting a laser beam to form a laser spot on the cylindrical product surface. The industrial camera simultaneously acquires nozzle positioning images, printed test strip images, and laser spot images. The spot position sensor, positioned on the same side as the industrial camera, synchronously detects the physical position coordinates of the laser spot. The image analysis unit fuses and corrects the image data and coordinate data, and calculates the nozzle position deviation, the splicing gap error between adjacent printheads, and the actual distance between the nozzle center and the product surface based on the corrected data. The calibration execution unit generates adjustment correction commands based on the calculation data from the image analysis unit and corrects the adjustment parameters of the XZR multi-axis servo drive mechanism through the control module.

[0006] Preferably, the mounting base is detachably mounted on the printing end of the printhead carriage via a locking and buffering mechanism, the locking and buffering mechanism including a positioning component, a locking component, and an elastic buffering component; The positioning component includes two cylindrical positioning pins and a diamond-shaped positioning hole disposed at the printing operation end of the printhead carriage. The mounting plate of the mounting base is provided with a positioning sleeve that is clearance-fitted with the cylindrical positioning pins. The mounting plate of the mounting base is also provided with a positioning boss that is interference-fitted with the diamond-shaped positioning hole. The locking assembly includes a plurality of cam-type quick clamps 821 distributed circumferentially along the base frame mounting plate. The fixed end of the cam-type quick clamp 821 is fixedly connected to the printing operation end of the printhead carriage, and its clamping end abuts against the locking seat 822 on the base frame mounting plate to press and fix the base frame mounting plate to the printing operation end of the printhead carriage. The elastic buffer assembly includes four sets spaced apart along the circumference of the base frame mounting plate. Each set of the elastic buffer assembly includes a guide post, a buffer spring, and a displacement sensor. One end of the guide post is fixed to the printing end of the printhead carriage, and the other end passes through the guide hole of the base frame mounting plate and is limited by a limiting cap. The buffer spring is sleeved on the outside of the guide post, and its two ends abut against the printing end of the printhead carriage and the base frame mounting plate respectively, maintaining a pre-compression amount. The displacement sensor is embedded in the side of the printing end of the printhead carriage facing the base frame mounting plate, and its detection end faces the surface of the base frame mounting plate to feed back the vibration displacement data of the base frame mounting plate to the XZR multi-axis servo drive mechanism to dynamically adjust the drive parameters.

[0007] Preferably, the XZR multi-axis servo drive mechanism includes an X-axis servo motor, a Z-axis servo motor, an R-axis servo motor, an X-axis moving plate, a Z-axis moving plate, and a position feedback unit; A Z-axis base frame is fixedly connected to the base frame mounting plate. A Z-axis linear guide rail module is fixedly mounted on the Z-axis base frame. The Z-axis moving plate is slidably mounted on the Z-axis linear guide rail module along the Z-axis direction. The output end of the Z-axis servo motor is connected to the Z-axis moving plate through a Z-axis ball screw drive assembly to drive the Z-axis moving plate to slide along the Z-axis direction. An X-axis base is fixedly connected to the Z-axis moving plate. An X-axis linear guide module is fixedly mounted on the X-axis base. The X-axis moving plate is slidably mounted on the X-axis linear guide module along the X-axis direction. The output end of the X-axis servo motor is connected to the X-axis moving plate through the X-axis ball screw drive module to drive the X-axis moving plate to slide horizontally along the X-axis direction. The printhead base plate includes two sets arranged facing each other along the Y-axis. The printhead base plate is rotatably mounted on the X-axis moving plate through a rotary bearing support. The R-axis servo motor is connected to the rotation center of the printhead base plate through a harmonic reducer to drive the printhead base plate to adjust the angle deflection along the R-axis. The R-axis axis is parallel to the arrangement direction of each printhead. An electromagnetic brake is provided between the output end of the harmonic reducer and the rotation center of the nozzle base plate. The harmonic reducer is also equipped with a torque sensor for real-time detection of the output torque of the R-axis servo motor. The control module is communicatively connected to the electromagnetic brake and the torque sensor. When the control module determines that the R-axis output torque exceeds a preset safety threshold or receives an emergency stop signal based on the data fed back by the torque sensor, it controls the electromagnetic brake to lock the rotation of the nozzle base plate. The position feedback unit includes an X-axis grating ruler, a Z-axis grating ruler, and an R-axis grating ruler, which respectively detect the linear displacement of the X-axis and Z-axis and the rotation angle of the R-axis, and feed them back to the control module for comparison with the target adjustment parameters. After calculating the deviation value, the feedback is sent to the corresponding servo motor for closed-loop dynamic compensation.

[0008] Preferably, the pressure compensation unit includes an ink pressure sensor, a proportional overflow valve, a micro booster pump, and a pressure damper. The ink pressure sensor is connected in series at the ink inlet of the printhead to detect the real-time ink pressure and feed it back to the control module. The proportional overflow valve is connected in parallel to the bypass branch of the ink path of the printhead for pressure relief and regulation. The micro booster pump is connected in series at the ink inlet of the ink path of the printhead and is communicatively connected to the control module along with the ink pressure sensor and the proportional overflow valve. When the XZR multi-axis servo drive mechanism adjusts the angle or displacement of the printhead base plate, the control module calculates the time-domain pressure deviation based on the real-time pressure fed back by the ink pressure sensor and the preset target pressure, and controls the voltage duty cycle of the micro booster pump or the proportional overflow valve to relieve pressure, so that the ink pressure of each printhead is kept within a constant range. The pressure damper is set in the ink path between the ink pressure sensor and the printhead to absorb the pressure pulsation caused by the action of the micro booster pump or the proportional overflow valve and keep the ink pressure stable.

[0009] Preferably, the formula for calculating the time-domain pressure deviation is:

[0010] in, For time-domain pressure deviation, Pre-set target pressure for the ink road, for Real-time pressure detected by the pressure sensor at all times; The control module outputs a control quantity to adjust the voltage duty cycle of the micro booster pump or the pressure relief of the proportional relief valve. The calculation formula for the control quantity is as follows: in, For the first The periodic controller outputs a control quantity. This is the proportionality coefficient. The integral coefficient is... The differential coefficients are... To control the cycle, For the first Periodic discretization of pressure deviation, For the first Periodic discretization of pressure deviation, From the initial period to the 1st The integral sum of the pressure deviations over the period; When the output control quantity ≥1 or When the value is ≤0, the accumulation of the integral term is paused, and the integral sum of the deviation remains unchanged from the previous period.

[0011] Preferably, the method for calculating the actual distance between the center of the nozzle of the print head and the surface of the cylindrical product is as follows: The industrial camera acquires images of laser spot on the surface of the cylindrical product, and performs grayscale noise reduction, edge contour extraction and center coordinate fitting in sequence to obtain the actual center coordinates of the laser spot on the camera imaging plane. The actual center coordinates of the light spot are compared with the preset reference position coordinates, and the pixel offset between the two on the imaging plane is calculated. Calculate the actual distance between the center of the printhead nozzle and the surface of the cylindrical product:

[0012] in, This refers to the actual distance between the center of the printhead nozzle and the surface of the cylindrical product. This refers to the angle between the axis of the industrial camera lens and the axis of the laser positioner, with an angle ranging from 30° to 45°. For industrial camera lens focal length, This represents the pixel offset of the laser spot on the camera's imaging plane. In camera pixel equivalents, This is the distance between the installation centers of the laser locator and the camera lens; Actual distance and preset distance threshold In comparison, generate a distance correction command in the Z-axis direction. ,when At that time, the image analysis unit transmits the correction command to the control module, which then issues a drive command to the XZR multi-axis servo drive mechanism to adjust the Z-axis position until... .

[0013] Preferably, the calibration execution unit uses a weighted fusion calibration algorithm to calculate the combined correction amount for the X-axis and R-axis, and generates corresponding correction instructions for the X-axis and R-axis. The formula for calculating the combined correction amount is:

[0014] in, For the first The nozzle position deviation of each print head in the X-axis direction. For the first The nozzle position deviation of each print head in the R-axis angle; For the first The overall correction amount of each printhead on the X-axis. For the first The overall correction amount of each printhead on the R-axis; This represents the current deflection angle of the R-axis. The center-to-center distance between adjacent nozzle orifices; For the first The and the first The splicing gap error of each nozzle, when For gap deviation, This is due to overlap deviation; For the first The and the first The splicing gap error of each nozzle, the first nozzle ; This is the weighting coefficient for the nozzle position deviation. This is the weighting coefficient for the splicing gap error, and ; when At that time, an X-axis correction command is sent to the control module to drive the XZR multi-axis servo drive mechanism to adjust the X-axis parameters. At that time, an R-axis correction command is sent to the control module to drive the XZR multi-axis servo drive mechanism to adjust the R-axis parameters, continuously correcting until the splicing gap error of all adjacent nozzles is corrected. .

[0015] Preferably, the printhead is a piezoelectric inkjet head. Each printhead independently and dynamically adjusts its driving voltage amplitude and pulse width based on the splicing gap error output by the multi-printhead collaborative calibration module to correct the ink droplet landing point deviation. The calculation formulas for the driving voltage amplitude and pulse width are as follows:

[0016] in, For the first The amplitude of the driving voltage for each nozzle. For the first The drive pulse width of each nozzle The reference driving voltage amplitude, As the reference drive pulse width, This is the voltage amplitude adjustment coefficient. This is the pulse width adjustment coefficient; when At the same time, the reference driving waveform parameters are maintained, i.e. , ;when At that time, the driving voltage amplitude and pulse width are dynamically adjusted according to the above formula until the splicing gap error meets the requirements for gapless splicing.

[0017] Preferably, the control module includes a parameter input unit, a data matching unit, and a drive control unit. The parameter input unit includes a touch screen, a data interface, and a diameter scanning component. The touch screen is embedded in the printhead carriage operation panel for manually inputting product diameter and printing speed parameters. The data interface includes a USB interface and an RS485 communication interface for receiving production parameters transmitted from an external MES system. The diameter scanning component includes two symmetrically arranged laser displacement sensors, whose detection ends face each other and cover the product conveying path to scan the product diameter in real time. The data matching unit, according to a range matching rule, calls the corresponding pre-stored adjustment parameters when the obtained product diameter is within a certain pre-stored diameter range. If there is no corresponding range, it generates adaptive adjustment parameters based on adjacent pre-stored parameters through an interpolation algorithm. The drive control unit, according to the pre-stored adjustment parameters or the adaptive adjustment parameters, sends drive commands to the XZR multi-axis servo drive mechanism and sends pressure control commands to the adaptive pressure compensation module to coordinate the synchronous operation of each component.

[0018] A method for adjusting the printhead of a high-speed disc printer for cylindrical products, the method employing the aforementioned high-speed disc printer printhead adjustment device, includes the following steps: S1. Obtain the diameter parameters and printing speed parameters of the cylindrical product to be printed. The control module calls the pre-stored adjustment parameters in the built-in parameter mapping database according to the diameter parameters. If there are no corresponding pre-stored parameters, the adaptive adjustment parameters are generated based on the adjacent pre-stored parameters through an interpolation algorithm. S2. The control module drives the XZR multi-axis servo drive mechanism to move the printhead base plate along the X-axis to directly above the product printing area according to the pre-stored adjustment parameters or the adaptive adjustment parameters, adjusts the nozzle to the preset initial distance between the nozzle and the product surface along the Z-axis, and deflects around the R-axis until the nozzle orientation is perpendicular to the tangent of the product surface. S3. The laser positioner emits a laser beam to form laser spots on the surface of the cylindrical product that correspond one-to-one with each print head. An industrial camera simultaneously acquires images of the nozzle positioning, the printed test strip, and the laser spot. A spot position sensor detects the physical coordinates of the laser spot. After the image analysis unit fuses and corrects the image data and coordinate data, it calculates the nozzle position deviation, the splicing gap error between adjacent print heads, and the actual distance between the nozzle and the product surface. The calibration execution unit generates corresponding correction instructions and adjusts the parameters of the XZR multi-axis servo drive mechanism through the control module until the splicing gap error and the distance deviation between the nozzle and the product surface meet the required printing range. S4. The ink pressure sensor detects the pressure at the ink inlet of each print head in real time. The control module calculates the time-domain pressure deviation and adjusts the voltage duty cycle of the micro booster pump or the pressure relief amount of the proportional overflow valve. Combined with the pressure buffer to absorb pressure pulsation, the ink pressure is stabilized within the constant range of the preset target pressure. S5. The disc printer drives the cylindrical product to rotate at a uniform speed. The control module coordinates the synchronous ink ejection of each print head. At the same time, based on the real-time feedback data from the multi-print head collaborative calibration module and the detection data from the print head temperature sensor, the print head drive voltage amplitude, pulse width, and XZR multi-axis servo drive mechanism parameters are dynamically adjusted to ensure that there is no ghosting, no gaps, and no color difference during the printing process. S6. The control module stops all components from working, the XZR multi-axis servo drive mechanism drives the nozzle base plate back to the initial position, and the proportional overflow valve completely releases pressure.

[0019] By adopting the above technical solution, the present invention has the following advantages compared with the prior art: 1. This invention provides a printhead adjustment device and method for a high-speed disc printer for cylindrical products. It integrates modules such as locking buffer, multi-axis drive, pressure compensation, and collaborative calibration. Through unified coordination by the control module, the structure is compact and the division of labor is clear. The locking buffer mechanism realizes the precise positioning and stable fixation of the mounting base, and the XZR multi-axis servo drive mechanism provides flexible and precise posture adjustment to adapt to the printing needs of cylindrical products with different diameters. The overall modular design reduces the difficulty of maintenance, and the collaborative work of each component improves the reliability and stability of the device in long-term operation.

[0020] 2. This invention provides a disc-type high-speed printer nozzle adjustment device and method for cylindrical products. A laser positioner and the nozzle orifice of the printer are collinear to form a precise reference spot. An industrial camera acquires three types of images: nozzle positioning, printed test strip, and laser spot. A spot position sensor synchronously detects the physical coordinates of the spot. After dual-source data fusion and correction, an image analysis unit accurately calculates the nozzle position deviation, splicing gap error, and the actual distance between the nozzle and the product surface. A calibration execution unit dynamically corrects the parameters of the XZR multi-axis servo drive mechanism through adjustment and correction commands. This completely solves the splicing gap and ghosting problems of traditional multi-nozzle printing, ensuring that cylindrical products of different diameters can achieve high-precision, gapless, and physically seamless splicing.

[0021] 3. This invention provides a printhead adjustment device and method for a high-speed disc printer for cylindrical products. The control module has a built-in parameter mapping database, which can directly call the pre-stored adjustment parameters that match the diameter of the input product, and drive the XZR multi-axis servo drive mechanism to complete the linear displacement of the X-axis and Z-axis and the angle deflection of the R-axis of the printhead base plate. This eliminates the need for repeated manual adjustments, greatly shortens the changeover time, adapts to the rapid switching needs of multi-specification products in large-scale mass production, and ensures the consistency of printing accuracy of different batches of products.

[0022] 4. This invention provides a printhead adjustment device and method for a disc high-speed printer for cylindrical products. Each printhead is equipped with an independent pressure compensation unit, and the pressure output end is connected to the ink path channel one by one. The ink path pressure is dynamically stabilized by the control module, which effectively avoids uneven ink output, color difference or broken lines caused by pressure fluctuations during high-speed printing or printhead posture adjustment, ensures stable ink output of each printhead, and improves the uniformity and clarity of printed images. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the XZR multi-axis servo drive mechanism of the present invention; Figure 3 This is a partially enlarged schematic diagram of the multi-nozzle collaborative calibration position of the present invention; Figure 4 This is a partially enlarged schematic diagram of the locking buffer position of the present invention; Figure 5 This is a flowchart of the method of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] It should be noted that in this invention, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are all based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element of this invention must have a specific orientation, and therefore should not be construed as a limitation of this invention. Example

[0026] Please refer to Figures 1 to 5 As shown, the present invention discloses a disc high-speed printer nozzle adjustment device for cylindrical products, including a mounting base 1, a nozzle base plate 2, a printing nozzle 3, an XZR multi-axis servo drive mechanism 4, an adaptive pressure compensation module 5, a multi-nozzle collaborative calibration module 6, a control module 7, and a locking buffer mechanism 8. The mounting base 1 is detachably mounted on the printing end 9 of the print head carriage through the locking buffer mechanism 8. The XZR multi-axis servo drive mechanism 4 is mounted on the mounting base 1 and is connected to the print head base plate 2 in a transmission manner. The control module 7 has a built-in parameter mapping database. By calling the pre-stored adjustment parameters in the parameter mapping database that match the diameter of the input cylindrical product, the control module 7 drives the printhead base plate 2 to adjust the linear displacement along the X-axis and Z-axis and the angle deflection adjustment around the R-axis parallel to the arrangement direction of the printhead 3. A number of printheads 3 with the same nozzle orientation are arranged at intervals on the printhead base plate 2. The adaptive pressure compensation module 5 includes a number of pressure compensation units respectively set for each printhead 3. The pressure output end of each pressure compensation unit is connected to the ink path channel of its corresponding printhead 3, and the ink path pressure is dynamically stabilized by the control module 7. The multi-nozzle collaborative calibration module 6 includes a laser positioner 61, an industrial camera 62, a spot position sensor 63, an image analysis unit 64, and a calibration execution unit. The laser positioner 61 includes several groups corresponding to the printing nozzles 3, and each group of laser positioners 61 is collinear with the central axis of the nozzle of the corresponding printing nozzle 3 and emits a laser beam to form a laser spot on the surface of the cylindrical product. The industrial camera 62 respectively acquires the nozzle positioning image, the printed test strip pattern, and the laser spot image. The spot position sensor 63 is set on the same side as the industrial camera 62 to synchronously detect the physical position coordinates of the laser spot and transmits them to the image analysis unit 64 for image data fusion correction. The image analysis unit 64 calculates and analyzes the nozzle position deviation, splicing gap error, and actual distance between the nozzle and the product surface based on the corrected nozzle positioning image, printed test strip pattern, and laser spot image. The calibration execution unit generates adjustment correction commands based on the nozzle position deviation, splicing gap error, and actual distance data, and corrects the adjustment parameters of the XZR multi-axis servo drive mechanism 4 through the control module 7.

[0027] In this embodiment, the laser positioner 61 is model LD-650-50, with an output wavelength of 650nm, a power of 50mW, a beam divergence angle ≤0.1mrad, and a coaxiality error between its axis and the corresponding nozzle center axis ≤0.02mm. The industrial camera 62 is a high-resolution CMOS area array camera. The spot position sensor 63 is model PSD-100, which is installed on the same side as the industrial camera. The distance between the detection center and the center of the camera lens is 50mm. The image analysis unit 64 uses an FPGA+ARM architecture processor, and the calibration execution unit is integrated into an STM32H743MCU.

[0028] The locking buffer mechanism 8 includes a positioning component 81, a locking component 82, and an elastic buffer component 83. The positioning component 81 includes two cylindrical positioning pins 811 and a diamond-shaped positioning hole set on the printing end 9 of the printhead carriage. The base mounting plate 11 of the mounting base 1 is provided with a positioning sleeve 12 that is clearance-fitted with the cylindrical positioning pins 811. The base mounting plate 11 is also provided with a positioning boss 13 that is interference-fitted with the diamond-shaped positioning hole (interference amount 0.01mm). The locking assembly 82 includes several GH-100 cam-type quick clamps 821 distributed circumferentially along the fixed seat. The fixed end of the cam-type quick clamp 821 is fixedly connected to the printing end of the printhead carriage 9, and its clamping end abuts against the locking seat 822 on the base frame mounting plate 11 to press and fix the base frame mounting plate 11 to the printing end of the printhead carriage 9. The elastic buffer assembly 83 includes four sets arranged circumferentially along the base frame mounting plate 11. Each set of elastic buffer assembly 83 includes a guide post 831, a buffer spring 832, and a displacement sensor 833. One end of the guide post 831 is fixed to the printhead carriage printing end 9, and the other end passes through the guide hole of the base frame mounting plate 11 and is limited by the limiting cap 834. The buffer spring 832 is sleeved on the outside of the guide post 831, and its two ends abut against the printhead carriage printing end 9 and the base frame mounting plate 11 respectively and maintain a pre-compression amount (pre-compression amount 10mm). The displacement sensor 833 is embedded on the side of the printhead carriage printing end 9 facing the base frame mounting plate 11, and its detection end faces the surface of the base frame mounting plate 11 to feed back the vibration displacement data of the base frame mounting plate 11 to the XZR multi-axis servo drive mechanism 4 to dynamically adjust the drive parameters.

[0029] The XZR multi-axis servo drive mechanism 4 includes an X-axis servo motor 41, a Z-axis servo motor 42, an R-axis servo motor 43, an X-axis moving plate 44, a Z-axis moving plate 45, and a position feedback unit 46. A Z-axis base frame 14 is fixedly connected to the base frame mounting plate 11. A Z-axis linear guide module 141 is fixedly mounted on the Z-axis base frame 14. A Z-axis moving plate 45 is slidably mounted on the Z-axis linear guide module 141 along the Z-axis direction. The output end of the Z-axis servo motor 42 is connected to the Z-axis moving plate 45 through the Z-axis ball screw drive assembly 142 to drive the Z-axis moving plate 45 to slide along the Z-axis direction. An X-axis base frame 15 is fixedly connected to the Z-axis moving plate 45. An X-axis linear guide module 151 is fixedly mounted on the X-axis base frame 15. An X-axis moving plate 44 is slidably mounted on the X-axis linear guide module 151 along the X-axis direction. The output end of the X-axis servo motor 41 is connected to the X-axis moving plate 44 through the X-axis ball screw drive module 152 to drive the X-axis moving plate 44 to slide horizontally along the X-axis direction. The printhead base plate 2 includes two sets arranged facing each other along the Y-axis. The printhead base plate 2 is rotatably mounted on the X-axis moving plate 44 through the rotating bearing support 21. The R-axis servo motor 43 is connected to the rotation center of the printhead base plate 2 through the harmonic reducer 22 to drive the printhead base plate 2 to adjust the angle deflection along the R-axis. The R-axis axis is parallel to the arrangement direction of each printhead 3. An electromagnetic brake is provided between the output end of the harmonic reducer 22 and the rotation center of the nozzle base plate 2. The harmonic reducer 22 is also equipped with a torque sensor 24 for real-time detection of the output torque of the R-axis servo motor 43. The control module 7 is communicatively connected to the electromagnetic brake and the torque sensor 24. When the control module 7 determines that the R-axis output torque exceeds the preset safety threshold or receives an emergency stop signal based on the data fed back by the torque sensor 24, it controls the electromagnetic brake to lock the rotation of the nozzle base plate 2. The position feedback unit 46 includes an X-axis grating ruler, a Z-axis grating ruler, and an R-axis grating ruler, which respectively detect the linear displacement of the X-axis and Z-axis and the rotation angle of the R-axis, and feed them back to the control module 7 for comparison with the target adjustment parameters. After calculating the deviation value, the feedback is sent to the corresponding servo motor for closed-loop dynamic compensation.

[0030] In this embodiment, the X-axis servo motor 41 and Z-axis servo motor 42 are model MS1H1-10B30CB-A331Z, the R-axis servo motor 43 is model MS1H1-05B30CB-A331Z, the X-axis linear guide module 151 and Z-axis linear guide module 141 are model THK-SRS15WM, the harmonic reducer 22 is model CSG-25-80-2UH, the electromagnetic brake is model SD-M1-24, the torque sensor 24 is model TS1206, the X-axis and Z-axis grating rulers are HEIDENHAIN-557646-02, and the R-axis grating ruler is model HEIDENHAIN-ROD426.

[0031] The pressure compensation unit includes an ink pressure sensor (model PTG501) 51, a proportional relief valve (model DBET-6X / 100G24K4V) 52, a miniature booster pump (PWM300) 53, and a pressure buffer 54. The ink pressure sensor 51 is connected in series at the ink inlet of the printhead 3 to detect the real-time ink pressure and feed it back to the control module 7. The proportional relief valve 52 is connected in parallel to the bypass branch of the ink path of the printhead 3 for pressure relief and regulation. The miniature booster pump 53 is connected in series at the ink inlet of the ink path of the printhead 3 and is connected in conjunction with the ink pressure sensor 51 and the proportional relief valve 52. All valves 52 are connected to the control module 7. When the XZR multi-axis servo drive mechanism 4 adjusts the angle or displacement of the printhead base plate 2, the control module 7 calculates the time-domain pressure deviation based on the real-time pressure fed back by the ink pressure sensor 51 and the preset target pressure, and controls the voltage duty cycle of the micro booster pump 53 or the proportional overflow valve 52 to release pressure, so that the ink path pressure of each printhead 3 is kept within a constant range. The pressure buffer 54 is set in the ink path between the ink pressure sensor 51 and the printhead 3 to absorb the pressure pulsation caused by the action of the micro booster pump 53 or the proportional overflow valve 52 to keep the ink path pressure stable.

[0032] The formula for calculating the time-domain pressure deviation of control module 7 is as follows:

[0033] in, For time-domain pressure deviation, Pre-set target pressure for the ink road, for Real-time pressure detected by the pressure sensor at all times; The control module 7 outputs a control quantity to adjust the voltage duty cycle of the micro booster pump or the pressure relief of the proportional relief valve. The calculation formula for the control quantity is as follows:

[0034] in, For the first The periodic controller outputs a control quantity. This is the proportionality coefficient. The integral coefficient is... The differential coefficients are... To control the cycle, For the first Periodic discretization of pressure deviation, For the first Periodic discretization of pressure deviation, From the initial period to the 1st The integral sum of the pressure deviations over the period; When the output control quantity ≥1 or When the value is ≤0, the accumulation of the integral term is paused, and the integral sum of the deviation remains unchanged from the previous period.

[0035] The specific method for calculating the actual distance between the nozzle center of print head 3 and the surface of the cylindrical product is as follows: The industrial camera 62 acquires images of laser spot on the surface of a cylindrical product, and performs grayscale noise reduction, edge contour extraction and center coordinate fitting in sequence to obtain the actual center coordinates of the laser spot on the camera imaging plane. The image analysis unit 64 compares the actual center coordinates of the light spot with the preset reference position coordinates and calculates the pixel offset between the two on the imaging plane. Calculate the actual distance between the center of the nozzle of print head 3 and the surface of the cylindrical product:

[0036] in, This refers to the actual distance between the center of the printhead nozzle and the surface of the cylindrical product. This refers to the angle between the axis of the industrial camera lens and the axis of the laser positioner, with an angle ranging from 30° to 45°. For industrial camera lens focal length, This represents the pixel offset of the laser spot on the camera's imaging plane. In camera pixel equivalents, This is the distance between the installation centers of the laser locator and the camera lens; Actual distance and preset distance threshold In comparison, generate a distance correction command in the Z-axis direction. ,when At that time, the image analysis unit 64 transmits the correction command to the control module 7, and the control module 7 issues a drive command to the XZR multi-axis servo drive mechanism 4 to adjust the Z-axis position until... .

[0037] The calibration execution unit uses a weighted fusion calibration algorithm to calculate the combined correction amount for the X-axis and R-axis, and generates corresponding correction commands for the X-axis and R-axis. The formula for calculating the combined correction amount is:

[0038] in, For the first The nozzle position deviation of each print head in the X-axis direction. For the first The nozzle position deviation of each print head in the R-axis angle; For the first The overall correction amount of each printhead on the X-axis. For the first The overall correction amount of each printhead on the R-axis; This represents the current deflection angle of the R-axis. The center-to-center distance between adjacent nozzle orifices; For the first The and the first The splicing gap error of each nozzle, when For gap deviation, This is due to overlap deviation; For the first The and the first The splicing gap error of each nozzle, the first nozzle ; This is the weighting coefficient for the nozzle position deviation. This is the weighting coefficient for the splicing gap error, and ; when At that time, the X-axis correction command is sent to the control module 7 to drive the XZR multi-axis servo drive mechanism 4 to adjust the X-axis parameters. At that time, the R-axis correction command is sent to the control module 7 to drive the XZR multi-axis servo drive mechanism 4 to adjust the R-axis parameters, and the correction is continued until the splicing gap error of all adjacent nozzles is corrected. .

[0039] Print head 3 is a piezoelectric inkjet head (model KM1024iM). Each print head 3 independently and dynamically adjusts the driving voltage amplitude and pulse width according to the splicing gap error output by the multi-print head collaborative calibration module 6 to correct the ink droplet landing point deviation. The calculation formulas for the driving voltage amplitude and pulse width are as follows:

[0040] in, For the first The amplitude of the driving voltage for each nozzle. For the first The drive pulse width of each nozzle The reference driving voltage amplitude, As the reference drive pulse width, This is the voltage amplitude adjustment coefficient. This is the pulse width adjustment coefficient; when At the same time, the reference driving waveform parameters are maintained, i.e. , ;when At that time, the driving voltage amplitude and pulse width are dynamically adjusted according to the above formula until the splicing gap error meets the requirements for gapless splicing.

[0041] The control module 7 includes a parameter input unit 71, a data matching unit, and a drive control unit. The parameter input unit includes a touch screen, a data interface, and a diameter scanning component. The touch screen is embedded in the printhead carriage operation panel for manually inputting product diameter and printing speed parameters. The data interface includes a USB interface and an RS485 communication interface for receiving production parameters transmitted from an external MES system. The diameter scanning component includes two symmetrically arranged laser displacement sensors (model KEYENCE-LK-G80), whose detection ends are opposite and cover the product conveying path to scan the product diameter in real time. The data matching unit, according to the range matching rule, calls the corresponding pre-stored adjustment parameters when the obtained product diameter is within a certain pre-stored diameter range. If there is no corresponding range, it generates adaptive adjustment parameters based on adjacent pre-stored parameters through an interpolation algorithm. The drive control unit sends drive commands to the XZR multi-axis servo drive mechanism 4 and sends pressure control commands to the adaptive pressure compensation module to coordinate the synchronous operation of each component according to the pre-stored adjustment parameters or the adaptive adjustment parameters.

[0042] The printhead base plate 2 is equipped with a printhead temperature control module (not shown in the figure). The printhead temperature control module includes a thin film heating element and a temperature sensor (model NTC-MF52) attached to the surface of each printhead 3. The temperature sensor monitors the real-time temperature of the printhead 3 and feeds it back to the control module 7 to control the corresponding thin film heating element to adjust the working temperature range of the printhead 3.

[0043] This invention also discloses a method for adjusting the printhead of a high-speed disc printer for cylindrical products, comprising the following steps: S1. Parameter input and matching: The diameter parameters and printing speed parameters of the cylindrical product to be printed are obtained through the touch screen, data interface or diameter scanning component. The control module 7 calls the pre-stored adjustment parameters in the built-in parameter mapping database according to the diameter parameters. If there are no corresponding pre-stored parameters, the adaptive adjustment parameters are generated based on the adjacent pre-stored parameters through the interpolation algorithm. S2, Printhead Pre-adjustment: The control module 7 drives the XZR multi-axis servo drive mechanism 4 to move the printhead base plate 2 along the X-axis to directly above the product printing area according to the pre-stored adjustment parameters or the adapted adjustment parameters, adjusts it along the Z-axis to the preset initial distance between the nozzle and the product surface, and deflects it around the R-axis until the nozzle orientation is perpendicular to the tangent of the product surface. S3. Multi-head collaborative calibration: The laser positioner 61 emits a laser beam to form laser spots corresponding to each printing nozzle 3 on the surface of the cylindrical product. The industrial camera 62 synchronously acquires the nozzle positioning image, the printed test strip image, and the laser spot image. The spot position sensor 63 detects the physical coordinates of the laser spot. After the image data and coordinate data are fused and corrected by the image analysis unit 64, the nozzle position deviation, the splicing gap error between adjacent nozzles, and the actual distance between the nozzle and the product surface are calculated. The calibration execution unit generates the corresponding correction command and adjusts the parameters of the XZR multi-axis servo drive mechanism 4 through the control module 7 until the splicing gap error and the distance deviation between the nozzle and the product surface meet the required range for printing. S4. Dynamic compensation of ink path pressure: The ink pressure sensor 51 detects the pressure at the ink path inlet of each print head 3 in real time. The control module 5 calculates the time-domain pressure deviation and adjusts the voltage duty cycle of the micro booster pump 53 or the pressure relief amount of the proportional overflow valve 52. Combined with the pressure buffer 54 to absorb pressure pulsation, the ink path pressure is stabilized within the constant range of the preset target pressure. S5. High-speed printing operation: The disc printer drives the cylindrical product to rotate at a constant speed. The control module 7 coordinates the synchronous ink jetting of each print head 3. At the same time, based on the real-time feedback data from the multi-print head collaborative calibration module 6 and the detection data from the print head temperature sensor, the print head drive voltage amplitude, pulse width and XZR multi-axis servo drive mechanism 4 parameters are dynamically adjusted to ensure that there is no ghosting, no gaps and no color difference during the printing process. S6, Printing ends: Control module 7 controls all components to stop working, XZR multi-axis servo drive mechanism 4 drives printhead base plate 2 to return to the initial position, and proportional overflow valve completely releases pressure.

[0044] The specific workflow and control logic of the device in this embodiment are as follows: 1) Device initialization phase: After the equipment is started, the control module 7 automatically executes the self-test process, the XZR multi-axis servo drive mechanism 4 drives each axis to return to the mechanical origin, the ink path system fills with ink and stabilizes the pressure to the preset target pressure of 0.3MPa, the temperature control module starts and heats the printhead temperature to 30℃; After the self-test is passed, the control module 7 enters the parameter input waiting state, which supports three parameter input methods: manual input via touch screen (product diameter, printing speed), receiving MES system parameters via USB / RS485 interface, and automatic scanning of product diameter via laser displacement sensor.

[0045] 2) Parameter matching and nozzle pre-adjustment stage: The data matching unit adopts the range matching rule. The parameter mapping database pre-stores 20 sets of standard diameters (intervals of 5mm) within the range of 10mm-100mm, corresponding to adjustment parameters (including initial position of X-axis, initial distance of Z-axis, initial angle of R-axis, ink pressure compensation coefficient, etc.). If the input product diameter is 50.2mm (within the 50mm-55mm pre-stored range), the pre-stored parameters for that range are directly used; if the input diameter is 52.3mm (no corresponding pre-stored range), the adaptation parameters are generated using a linear interpolation algorithm based on the pre-stored parameters corresponding to 45mm and 50mm. According to the matched parameters, the control module 7 sends a drive command to the XZR multi-axis servo drive mechanism 4 to drive the printhead base plate 2 to complete the pre-adjustment: the X-axis moves to the top of the product printing area, the Z-axis is adjusted to the initial distance of 2mm between the nozzle and the product surface, and the R-axis is deflected to the nozzle orientation perpendicular to the tangent of the product surface (deflection angle error ≤ 0.001rad).

[0046] 3) Multi-nozzle collaborative calibration stage: The laser positioner 61 is activated, emitting a laser beam onto the surface of the cylindrical product to form a laser spot (spot diameter ≤ 0.1 mm) that corresponds one-to-one with the nozzle. The industrial camera 62 simultaneously acquires three types of images: nozzle positioning image (used to identify the actual position of the nozzle), printed test strip pattern (a 10mm×1mm black test strip pre-printed by the nozzle, used to detect splicing gaps), and laser spot image (used to calculate distance deviation). The acquisition frequency is synchronized with the printing speed. The laser spot position sensor 63 synchronously detects the physical position coordinates of the laser spot and transmits them together with the image data acquired by the industrial camera 62 to the image analysis unit 64; The image analysis unit 64 fuses and corrects multi-source data, employing a Kalman filter algorithm to eliminate ambient light interference and mechanical vibration effects. The error between the corrected image coordinates and physical coordinates is ≤0.002mm. Based on the corrected data, the core parameter, nozzle position deviation, is calculated. , splicing gap error The actual distance between the center of the nozzle of print head 3 and the surface of the cylindrical product. ; The calibration execution unit generates correction instructions: when At that time, the image analysis unit 64 transmits the correction command to the control module 7, and the control module 7 issues a drive command to the XZR multi-axis servo drive mechanism 4 to adjust the Z-axis position until... .

[0047] when At that time, the X-axis correction command is sent to the control module 7 to drive the XZR multi-axis servo drive mechanism 4 to adjust the X-axis parameters. At that time, the R-axis correction command is sent to the control module 7 to drive the XZR multi-axis servo drive mechanism 4 to adjust the R-axis parameters, and the correction is continued until the splicing gap error of all adjacent nozzles is corrected. .

[0048] 4) Dynamic compensation stage during printing process During printing, ink pressure sensor 51 monitors the ink path pressure of each printhead in real time, and control module 7 calculates the time-domain pressure deviation. Then, the output control quantity is calculated using the discretized PID formula. Adjust the voltage duty cycle of the micro booster pump 53 or the pressure relief amount of the proportional overflow valve 52; PID parameter presets: =1.2, =0.05, =0.005, =10ms When the output control quantity When ≥1, the miniature booster pump 53 operates at its maximum voltage duty cycle, pausing the accumulation of the integral term, and when the output control quantity... When the pressure is ≤0, the proportional relief valve 52 is fully opened to release pressure and the accumulation of the integral term is suspended; Pressure buffer 54 absorbs pressure pulsations, ensuring that the ink path pressure is stable at 0.3MPa±0.01MPa, and avoiding fluctuations in ink output. The multi-nozzle collaborative calibration module 6 operates continuously, completing data acquisition and calibration calculation every 10ms. When splicing gap error is detected... or distance deviation In real time, correction commands are issued to dynamically adjust the X-axis, Z-axis, and R-axis parameters; The temperature sensor monitors the printhead temperature in real time. When the temperature is below 25℃, the control module 7 activates the corresponding film heating element; when the temperature is above 35℃, the film heating element is turned off to ensure that the printhead operating temperature is stable between 25℃ and 35℃, and to avoid fluctuations in ink droplet ejection speed (speed fluctuation ≤1%) caused by temperature changes.

[0049] 5) Security protection mechanism: The torque sensor 24 detects the output torque of the R-axis servo motor 43 in real time. When the torque exceeds the preset safety threshold of 5 N·m, the control module 7 immediately sends a locking command to the electromagnetic brake to lock the rotation of the nozzle base plate 3 (locking response time ≤ 10 ms). When an emergency stop signal is received (hardware emergency stop button or software emergency stop command), the control module 7 simultaneously triggers three actions: the XZR multi-axis servo drive mechanism 4 stops working, the electromagnetic brake locks the R-axis, the micro booster pump 53 stops working, and the proportional relief valve 52 completely releases pressure to ensure the safety of the equipment and products. When the displacement sensor detects that the vibration displacement of the base frame mounting plate 11 exceeds 0.01mm, the control module 7 sends a vibration compensation command to the XZR multi-axis servo drive mechanism 4 to adjust the drive parameters of each axis to offset the vibration effect. The compensation response time is ≤20ms.

[0050] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A disc-type high-speed printer nozzle adjustment device for cylindrical products, characterized in that: Includes mounting base, nozzle base plate, XZR multi-axis servo drive mechanism, adaptive pressure compensation module, multi-nozzle collaborative calibration module and control module; The mounting base is detachably mounted on the printing end of the printhead carriage. The XZR multi-axis servo drive mechanism is mounted on the mounting base and is connected to the printhead base plate. Several printheads with the same nozzle orientation are spaced apart on the printhead base plate. The control module controls the XZR multi-axis servo drive mechanism to drive the printhead base plate to achieve linear displacement adjustment along the X-axis and Z-axis, and angle deflection adjustment around the R-axis parallel to the printhead arrangement direction by calling the pre-stored adjustment parameters in the built-in parameter mapping database that match the diameter of the cylindrical product to be printed. The adaptive pressure compensation module includes several pressure compensation units corresponding to each printhead. The pressure output terminal of each pressure compensation unit is connected to the ink path channel of its corresponding printhead, and the ink path pressure is dynamically stabilized by the control module. The multi-nozzle collaborative calibration module includes a laser positioner, an industrial camera, a spot position sensor, an image analysis unit, and a calibration execution unit. The laser positioner comprises several groups corresponding to the printheads, with each group collinear with the central axis of the corresponding printhead nozzle and emitting a laser beam to form a laser spot on the cylindrical product surface. The industrial camera simultaneously acquires nozzle positioning images, printed test strip images, and laser spot images. The spot position sensor, positioned on the same side as the industrial camera, synchronously detects the physical position coordinates of the laser spot. The image analysis unit fuses and corrects the image data and coordinate data, and calculates the nozzle position deviation, the splicing gap error between adjacent printheads, and the actual distance between the nozzle center and the product surface based on the corrected data. The calibration execution unit generates adjustment correction commands based on the calculation data from the image analysis unit and corrects the adjustment parameters of the XZR multi-axis servo drive mechanism through the control module.

2. The disc-type high-speed printer nozzle adjustment device for cylindrical products as described in claim 1, characterized in that: The mounting base is detachably mounted on the printing end of the printhead carriage via a locking and buffering mechanism, which includes a positioning component, a locking component, and an elastic buffering component. The positioning component includes two cylindrical positioning pins and a diamond-shaped positioning hole disposed at the printing operation end of the printhead carriage. The mounting plate of the mounting base is provided with a positioning sleeve that is clearance-fitted with the cylindrical positioning pins. The mounting plate of the mounting base is also provided with a positioning boss that is interference-fitted with the diamond-shaped positioning hole. The locking assembly includes a plurality of cam-type quick clamps 821 distributed circumferentially along the base frame mounting plate. The fixed end of the cam-type quick clamp 821 is fixedly connected to the printing operation end of the printhead carriage, and its clamping end abuts against the locking seat 822 on the base frame mounting plate to press and fix the base frame mounting plate to the printing operation end of the printhead carriage. The elastic buffer assembly includes four sets spaced apart along the circumference of the base frame mounting plate. Each set of the elastic buffer assembly includes a guide post, a buffer spring, and a displacement sensor. One end of the guide post is fixed to the printing end of the printhead carriage, and the other end passes through the guide hole of the base frame mounting plate and is limited by a limiting cap. The buffer spring is sleeved on the outside of the guide post, and its two ends abut against the printing end of the printhead carriage and the base frame mounting plate respectively, maintaining a pre-compression amount. The displacement sensor is embedded in the side of the printing end of the printhead carriage facing the base frame mounting plate, and its detection end faces the surface of the base frame mounting plate to feed back the vibration displacement data of the base frame mounting plate to the XZR multi-axis servo drive mechanism to dynamically adjust the drive parameters.

3. The disc-type high-speed printer nozzle adjustment device for cylindrical products as described in claim 2, characterized in that: The XZR multi-axis servo drive mechanism includes an X-axis servo motor, a Z-axis servo motor, an R-axis servo motor, an X-axis moving plate, a Z-axis moving plate, and a position feedback unit. A Z-axis base frame is fixedly connected to the base frame mounting plate. A Z-axis linear guide rail module is fixedly mounted on the Z-axis base frame. The Z-axis moving plate is slidably mounted on the Z-axis linear guide rail module along the Z-axis direction. The output end of the Z-axis servo motor is connected to the Z-axis moving plate through a Z-axis ball screw drive assembly to drive the Z-axis moving plate to slide along the Z-axis direction. An X-axis base is fixedly connected to the Z-axis moving plate. An X-axis linear guide module is fixedly mounted on the X-axis base. The X-axis moving plate is slidably mounted on the X-axis linear guide module along the X-axis direction. The output end of the X-axis servo motor is connected to the X-axis moving plate through the X-axis ball screw drive module to drive the X-axis moving plate to slide horizontally along the X-axis direction. The printhead base plate includes two sets arranged facing each other along the Y-axis. The printhead base plate is rotatably mounted on the X-axis moving plate through a rotary bearing support. The R-axis servo motor is connected to the rotation center of the printhead base plate through a harmonic reducer to drive the printhead base plate to adjust the angle deflection along the R-axis. The R-axis axis is parallel to the arrangement direction of each printhead. An electromagnetic brake is provided between the output end of the harmonic reducer and the rotation center of the nozzle base plate. The harmonic reducer is also equipped with a torque sensor for real-time detection of the output torque of the R-axis servo motor. The control module is communicatively connected to the electromagnetic brake and the torque sensor. When the control module determines that the R-axis output torque exceeds a preset safety threshold or receives an emergency stop signal based on the data fed back by the torque sensor, it controls the electromagnetic brake to lock the rotation of the nozzle base plate. The position feedback unit includes an X-axis grating ruler, a Z-axis grating ruler, and an R-axis grating ruler, which respectively detect the linear displacement of the X-axis and Z-axis and the rotation angle of the R-axis, and feed them back to the control module for comparison with the target adjustment parameters. After calculating the deviation value, the feedback is sent to the corresponding servo motor for closed-loop dynamic compensation.

4. The disc-type high-speed printer nozzle adjustment device for cylindrical products as described in claim 3, characterized in that: The pressure compensation unit includes an ink pressure sensor, a proportional overflow valve, a micro booster pump, and a pressure damper. The ink pressure sensor is connected in series at the ink inlet of the printhead to detect the real-time ink pressure and feed it back to the control module. The proportional overflow valve is connected in parallel to the bypass branch of the ink path of the printhead for pressure relief and regulation. The micro booster pump is connected in series at the ink inlet of the ink path of the printhead and is communicatively connected to the control module along with the ink pressure sensor and the proportional overflow valve. When the XZR multi-axis servo drive mechanism adjusts the angle or displacement of the printhead base plate, the control module calculates the time-domain pressure deviation based on the real-time pressure fed back by the ink pressure sensor and the preset target pressure, and controls the voltage duty cycle of the micro booster pump or the proportional overflow valve to relieve pressure, so that the ink pressure of each printhead is kept within a constant range. The pressure damper is set in the ink path between the ink pressure sensor and the printhead to absorb the pressure pulsation caused by the action of the micro booster pump or the proportional overflow valve and keep the ink pressure stable.

5. The disc-type high-speed printer nozzle adjustment device for cylindrical products as described in claim 4, characterized in that: The formula for calculating the time-domain pressure deviation is: in, For time-domain pressure deviation, Pre-set target pressure for the ink road, for Real-time pressure detected by the pressure sensor at all times; The control module outputs a control quantity to adjust the voltage duty cycle of the micro booster pump or the pressure relief of the proportional relief valve. The calculation formula for the control quantity is as follows: in, For the first The periodic controller outputs a control quantity. This is the proportionality coefficient. The integral coefficient is... The differential coefficients are... To control the cycle, For the first Periodic discretization of pressure deviation, For the first Periodic discretization of pressure deviation, From the initial period to the 1st The integral sum of the pressure deviations over the period; When the output control quantity ≥1 or When the value is ≤0, the accumulation of the integral term is paused, and the integral sum of the deviation remains unchanged from the previous period.

6. The disc-type high-speed printer nozzle adjustment device for cylindrical products as described in claim 5, characterized in that: The specific method for calculating the actual distance between the nozzle center of the print head and the surface of the cylindrical product is as follows: The industrial camera acquires images of laser spot on the surface of the cylindrical product, and performs grayscale noise reduction, edge contour extraction and center coordinate fitting in sequence to obtain the actual center coordinates of the laser spot on the camera imaging plane. The actual center coordinates of the light spot are compared with the preset reference position coordinates, and the pixel offset between the two on the imaging plane is calculated. Calculate the actual distance between the center of the printhead nozzle and the surface of the cylindrical product: in, This refers to the actual distance between the center of the printhead nozzle and the surface of the cylindrical product. This refers to the angle between the axis of the industrial camera lens and the axis of the laser positioner, with an angle ranging from 30° to 45°. For industrial camera lens focal length, This represents the pixel offset of the laser spot on the camera's imaging plane. In camera pixel equivalents, This is the distance between the installation centers of the laser locator and the camera lens; Actual distance and preset distance threshold In comparison, generate a distance correction command in the Z-axis direction. ,when At that time, the image analysis unit transmits the correction command to the control module, which then issues a drive command to the XZR multi-axis servo drive mechanism to adjust the Z-axis position until... .

7. The disc-type high-speed printer nozzle adjustment device for cylindrical products as described in claim 6, characterized in that: The calibration execution unit uses a weighted fusion calibration algorithm to calculate the combined correction amount for the X-axis and R-axis, and generates corresponding correction instructions for the X-axis and R-axis. The formula for calculating the combined correction amount is as follows: in, For the first The nozzle position deviation of each print head in the X-axis direction. For the first The nozzle position deviation of each print head in the R-axis angle; For the first The overall correction amount of each printhead on the X-axis. For the first The overall correction amount of each printhead on the R-axis; This represents the current deflection angle of the R-axis. The center-to-center distance between adjacent nozzle orifices; For the first The and the first The splicing gap error of each nozzle, when For gap deviation, This is due to overlap deviation; For the first The and the first The splicing gap error of each nozzle, the first nozzle ; This is the weighting coefficient for the nozzle position deviation. This is the weighting coefficient for the splicing gap error, and ; when At that time, an X-axis correction command is sent to the control module to drive the XZR multi-axis servo drive mechanism to adjust the X-axis parameters. At that time, an R-axis correction command is sent to the control module to drive the XZR multi-axis servo drive mechanism to adjust the R-axis parameters, continuously correcting until the splicing gap error of all adjacent nozzles is corrected. .

8. The disc-type high-speed printer nozzle adjustment device for cylindrical products as described in claim 7, characterized in that: The printhead is a piezoelectric inkjet head. Each printhead independently and dynamically adjusts its driving voltage amplitude and pulse width based on the splicing gap error output by the multi-printhead collaborative calibration module to correct the ink droplet landing point deviation. The calculation formulas for the driving voltage amplitude and pulse width are as follows: in, For the first The amplitude of the driving voltage for each nozzle. For the first The drive pulse width of each nozzle The reference driving voltage amplitude, As the reference drive pulse width, This is the voltage amplitude adjustment coefficient. This is the pulse width adjustment coefficient; when At the same time, the reference driving waveform parameters are maintained, i.e. , ;when At that time, the driving voltage amplitude and pulse width are dynamically adjusted according to the above formula until the splicing gap error meets the requirements for gapless splicing.

9. The disc-type high-speed printer nozzle adjustment device for cylindrical products as described in claim 8, characterized in that: The control module includes a parameter input unit, a data matching unit, and a drive control unit. The parameter input unit includes a touch screen, a data interface, and a diameter scanning component. The touch screen is embedded in the printhead carriage operation panel for manually inputting product diameter and printing speed parameters. The data interface includes a USB interface and an RS485 communication interface for receiving production parameters transmitted from an external MES system. The diameter scanning component includes two symmetrically arranged laser displacement sensors whose detection ends face each other and cover the product conveying path to scan the product diameter in real time. The data matching unit, according to a range matching rule, calls the corresponding pre-stored adjustment parameters when the obtained product diameter is within a certain pre-stored diameter range. If there is no corresponding range, it generates adaptive adjustment parameters based on adjacent pre-stored parameters using an interpolation algorithm. The drive control unit, based on the pre-stored adjustment parameters or the adaptive adjustment parameters, sends drive commands to the XZR multi-axis servo drive mechanism and sends pressure control commands to the adaptive pressure compensation module to coordinate the synchronous operation of each component.

10. A method for adjusting the printhead of a high-speed disc printer based on a cylindrical product according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Obtain the diameter parameters and printing speed parameters of the cylindrical product to be printed. The control module calls the pre-stored adjustment parameters in the built-in parameter mapping database according to the diameter parameters. If there are no corresponding pre-stored parameters, the adaptive adjustment parameters are generated based on the adjacent pre-stored parameters through an interpolation algorithm. S2. The control module drives the XZR multi-axis servo drive mechanism to move the printhead base plate along the X-axis to directly above the product printing area according to the pre-stored adjustment parameters or the adaptive adjustment parameters, adjusts the nozzle to the preset initial distance between the nozzle and the product surface along the Z-axis, and deflects around the R-axis until the nozzle orientation is perpendicular to the tangent of the product surface. S3. The laser positioner emits a laser beam to form laser spots on the surface of the cylindrical product that correspond one-to-one with each print head. An industrial camera simultaneously acquires images of the nozzle positioning, the printed test strip, and the laser spot. A spot position sensor detects the physical coordinates of the laser spot. After the image analysis unit fuses and corrects the image data and coordinate data, it calculates the nozzle position deviation, the splicing gap error between adjacent print heads, and the actual distance between the nozzle and the product surface. The calibration execution unit generates corresponding correction instructions and adjusts the parameters of the XZR multi-axis servo drive mechanism through the control module until the splicing gap error and the distance deviation between the nozzle and the product surface meet the required printing range. S4. The ink pressure sensor detects the pressure at the ink inlet of each print head in real time. The control module calculates the time-domain pressure deviation and adjusts the voltage duty cycle of the micro booster pump or the pressure relief amount of the proportional overflow valve. Combined with the pressure buffer to absorb pressure pulsation, the ink pressure is stabilized within the constant range of the preset target pressure. S5. The disc printer drives the cylindrical product to rotate at a uniform speed. The control module coordinates the synchronous ink ejection of each print head. At the same time, based on the real-time feedback data from the multi-print head collaborative calibration module and the detection data from the print head temperature sensor, the print head drive voltage amplitude, pulse width, and XZR multi-axis servo drive mechanism parameters are dynamically adjusted to ensure that there is no ghosting, no gaps, and no color difference during the printing process. S6. The control module stops all components from working, the XZR multi-axis servo drive mechanism drives the nozzle base plate back to the initial position, and the proportional overflow valve completely releases pressure.

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