Nozzle cleaning device pressure control method and device, electronic equipment and storage medium

Abstract

This application relates to the field of inkjet printing equipment technology, and in particular to a pressure control method, device, electronic equipment, and storage medium for a printhead cleaning device. After cleaning, the control card drives the ink pump to work at the target pressure, and the pressure sensor collects the pipeline cleaning pressure in real time; it determines whether the pressure is within the allowable fluctuation range, and if it exceeds the range, it calculates the deviation value, classifies the deviation state, and predicts the pressure change trend; based on this, it coordinates the adjustment of the ink pump power and the solenoid valve pressure relief action to stabilize the pressure within the target range; after the cleaning time is met, the machine stops and the solenoid valve resets. This application achieves closed-loop constant control of cleaning pressure, can identify pressure abnormalities in real time, avoids damage to the printhead due to excessive pressure or incomplete cleaning due to excessive pressure, and improves cleaning stability and printhead lifespan.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inkjet printing equipment, and particularly relates to a pressure control method and device for a nozzle cleaning device, an electronic device and a storage medium. BACKGROUND

[0002] In an inkjet printing device, a nozzle, as a core imaging component, its internal flow channel and nozzle cleaning state directly determine the printing precision, image quality and overall service life of the device. In the long-term printing process, ink impurities and dry ink stains are easily left in the nozzle, and a special nozzle cleaning device needs to be used to perform ink suction cleaning operation regularly to ensure the smoothness of the nozzle and the stability of printing.

[0003] The existing nozzle cleaning device adopts a structure form in which an ink pump motor is directly connected with an ink suction pad, and only relies on preset driving parameters to adjust the cleaning intensity, without setting a real-time pressure detection link and a closed-loop feedback control mechanism based on the actual pressure, so that the actual cleaning pressure is prone to deviate from the target pressure, and the cleaning intensity cannot match the actual demand of the nozzle under the working conditions of ink pump performance attenuation, pipeline leakage or ink suction pad blockage. In addition, due to the lack of closed-loop regulation, the pressure is prone to be too high to break the nozzle diaphragm and damage the internal flow channel of the nozzle, or the pressure is too low to effectively remove the residual ink stains and cause nozzle blockage, which reduces the printing quality and shortens the service life of the nozzle. SUMMARY

[0004] In order to overcome the deficiencies of the prior art, the present application provides a nozzle cleaning device pressure control method, device, electronic device and storage medium, which realizes real-time identification of pressure abnormalities through a complete closed-loop control logic of pressure real-time acquisition-deviation calculation-classification determination-trend prediction-collaborative regulation, avoids damage to the nozzle due to too high pressure or incomplete cleaning due to too low pressure, and improves the cleaning stability and the service life of the nozzle.

[0005] A first aspect of the present application provides a nozzle cleaning device pressure control method applied to a control card of the nozzle cleaning device, wherein the nozzle cleaning device further comprises an ink pump motor, a pressure sensor, a three-way air release electromagnetic valve, a matched pipeline and a waste ink collection box; the three-way air release electromagnetic valve comprises three interfaces, a first interface is connected with an output end of the ink pump motor, a second interface is connected with an input end of the pressure sensor, and a third interface is connected with a pressure release channel leading to the waste ink collection box; the pressure sensor is arranged on the matched pipeline between the three-way air release electromagnetic valve and a nozzle cleaning interface, and the method comprises the following steps: When a cleaning process starting signal is received, the ink pump motor is controlled according to a preset nozzle cleaning target pressure to start, and cleaning medium is delivered to the matched pipeline, so that the ink suction pad at the nozzle cleaning interface carries out nozzle cleaning; Obtain the real-time pressure of the first nozzle cleaning in the supporting pipeline collected by the pressure sensor; Judge whether the real-time pressure of the first nozzle cleaning is within the allowable pressure fluctuation range; When it is determined that the real-time pressure of the first nozzle cleaning is not within the allowable pressure fluctuation range, calculate the deviation value between the real-time pressure of the first nozzle cleaning and the target pressure of the nozzle cleaning; Judge the pressure deviation state according to the deviation value by grading, and predict the pressure deviation direction based on the actual change trend of the deviation value; According to the pressure deviation state and the pressure deviation direction, adjust the driving power of the ink pump motor and the pressure relief action of the three-way air release solenoid valve, so that the real-time pressure of the first nozzle cleaning returns to and stabilizes within the allowable pressure fluctuation range; When the preset cleaning duration is met, control the ink pump motor to stop working, and control the three-way air release solenoid valve to reset to the initial closed state.

[0006] In an optional embodiment, the pressure deviation state includes a mild overpressure state, a mild underpressure state, an overpressure critical state, and an underpressure critical state, and the pressure deviation direction includes an upward trend and a downward trend; the adjusting the driving power of the ink pump motor and the pressure relief action of the three-way air release solenoid valve according to the pressure deviation state and the pressure deviation direction, so that the real-time pressure of the first nozzle cleaning returns to and stabilizes within the allowable pressure fluctuation range includes: When it is determined that the pressure deviation state is a mild overpressure state and the pressure deviation direction shows an upward trend, control the driving power of the ink pump motor to be lowered for feedforward pressure suppression, and at the same time control the three-way air release solenoid valve to be in a slightly open standby state; When it is determined that the pressure deviation state is a mild underpressure state and the pressure deviation direction shows a downward trend, control the driving power of the ink pump motor to be increased for feedforward pressure compensation, and at the same time control the three-way air release solenoid valve to be in a fully closed state; When it is determined that the pressure deviation state is an overpressure critical state and the pressure deviation direction is a continuous upward trend, control the three-way air release solenoid valve to open the pressure release channel to release the pressure of the supporting pipeline according to the pre-stored pressure relief duration-pressure drop curve until the real-time pressure of the nozzle cleaning drops back to within the allowable pressure fluctuation range; the pressure relief duration-pressure drop curve is a one-to-one correspondence curve of the pressure relief duration of a single opening of the three-way air release solenoid valve and the pressure drop in the supporting pipeline calibrated and stored in advance; When the pressure deviation is determined to be a critical underpressure state and the pressure deviation direction is a continuous downward trend, the three-way venting solenoid valve is controlled to keep the pressure release channel closed, and the ink pump motor drive power is controlled to increase to boost the pressure until the real-time pressure of the printhead cleaning rises back to the allowable pressure fluctuation range.

[0007] In an optional implementation, the step of determining the pressure deviation state based on the deviation value includes: When the real-time pressure of the first nozzle cleaning is greater than the target pressure of the nozzle cleaning but less than the upper limit of the fluctuation, the pressure deviation state is determined to be a slight overpressure state; the allowable pressure fluctuation range includes the upper limit of the fluctuation and the lower limit of the fluctuation. When the real-time pressure of the first nozzle cleaning is less than the target pressure of the nozzle cleaning but greater than the lower limit of the fluctuation, the pressure deviation state is determined to be a slightly under-pressure state. When the real-time cleaning pressure of the first nozzle is greater than or equal to the upper limit of the fluctuation, the pressure deviation state is determined to be an overpressure critical state. When the real-time cleaning pressure of the first nozzle is less than or equal to the lower limit of the fluctuation, the pressure deviation state is determined to be an underpressure critical state.

[0008] In an optional implementation, predicting the direction of pressure deviation based on the actual trend of the deviation value includes: When the deviation value of the first preset time period shows an increasing trend, it is determined that the pressure is deviating from the direction away from the cleaning target pressure of the nozzle, and it is determined that the direction of pressure deviation is increasing. When the deviation value of the first preset time period shows a decreasing trend, it is determined that the pressure is deviating in the direction of approaching the nozzle cleaning target pressure, and the pressure deviation direction is determined to be decreasing. If the deviation value remains unchanged for the first preset time period, it is determined that the pressure deviation direction is in a steady state with no offset.

[0009] In an optional implementation, the method further includes: Calculate the fluid resistance value Z in the supporting pipeline, Z=(Pin−Pout) / Q, where Pin is the outlet pressure of the three-way venting solenoid valve, Pout is the pressure at the nozzle cleaning interface, and Q is the real-time flow rate of the cleaning medium in the supporting pipeline. Based on the deviation rate between the impedance value and the reference impedance value, the power adjustment range of the ink pump motor and the depressurization time of the three-way venting solenoid valve are dynamically corrected; including: when the fluid impedance value is greater than the reference impedance value, increasing the power adjustment range of the ink pump motor and shortening the single depressurization time of the three-way venting solenoid valve; when the fluid impedance value is less than the reference impedance value, decreasing the power adjustment range of the ink pump motor and extending the single depressurization time of the three-way venting solenoid valve; the reference impedance value is the initial pipeline impedance value obtained by the no-load calibration of the printhead cleaning device.

[0010] In an optional implementation, before controlling the ink pump motor to stop operating when the preset cleaning time is met, the method further includes: The ink pump motor is controlled to perform a gradient power reduction operation, which reduces the driving power of the ink pump motor from the normal working power adapted to the printhead cleaning target pressure according to a preset decreasing gradient, and continuously acquires the real-time pressure of the second printhead cleaning collected by the pressure sensor during the gradient power reduction process. When the real-time pressure of the second nozzle cleaning drops to a preset ratio of the target pressure of the nozzle cleaning, the three-way venting solenoid valve is controlled to open at a preset micro-opening degree to release pressure on the supporting pipeline, and the real-time pressure of the third nozzle cleaning collected by the pressure sensor is continuously acquired during the pressure release process. When the real-time cleaning pressure of the third printhead drops to the normal pressure range, the ink pump motor is controlled to completely stop working, and the three-way venting solenoid valve is controlled to reset to the initial closed state; wherein, the normal pressure range is the environmental pressure range when there is no cleaning medium being transported in the supporting pipeline.

[0011] In an optional implementation, the method further includes: When the real-time pressure of the nozzle cleaning is within the pressure abnormality alarm threshold range for a continuous second preset time period, a pressure abnormality alarm signal is generated; the pressure abnormality alarm threshold range includes an upper limit and a lower limit of the pressure abnormality alarm threshold. The faulty component is located based on the type of pressure anomaly. The pressure anomaly types include overpressure anomaly and underpressure anomaly. When the real-time pressure of the printhead cleaning is higher than the upper limit of the pressure anomaly alarm threshold for a continuous second preset time period, the faulty component is determined to be the ink suction pad. When the real-time pressure of the printhead cleaning is lower than the lower limit of the pressure anomaly alarm threshold for a continuous second preset time period, the faulty component is determined to be the ink pump motor or its supporting pipeline.

[0012] A second aspect of this application provides a nozzle cleaning device, the device comprising: The system includes a control card, an ink pump motor, a pressure sensor, a three-way venting solenoid valve, matching piping, and a waste ink collection box. The three-way venting solenoid valve has three interfaces: the first interface connects to the output of the ink pump motor, the second interface connects to the input of the pressure sensor, and the third interface connects to the waste ink collection box via a pressure release channel. The pressure sensor is located on the matching piping between the three-way venting solenoid valve and the printhead cleaning interface. The control card is electrically connected to the ink pump motor, the pressure sensor, and the three-way venting solenoid valve. The control card is configured to: when receiving a cleaning process start signal, control the ink pump motor to start according to the preset printhead cleaning target pressure, deliver cleaning medium to the printhead cleaning interface through the matching pipeline, and perform printhead cleaning in conjunction with the ink suction pad; acquire the real-time pressure of the first printhead cleaning in the matching pipeline collected by the pressure sensor; determine whether the real-time pressure of the first printhead cleaning is within the pressure fluctuation range; when it is not within the pressure fluctuation range, calculate the deviation value between the real-time pressure of the first printhead cleaning and the printhead cleaning target pressure; classify the pressure deviation state according to the deviation value, and predict the pressure deviation direction based on the changing trend of the deviation value; adjust the drive power of the ink pump motor and the pressure relief action of the three-way venting solenoid valve according to the pressure deviation state and the pressure deviation direction, so that the real-time pressure of the first printhead cleaning returns to and stabilizes within the pressure fluctuation range; when the preset cleaning time is met, control the ink pump motor to stop working, and control the three-way venting solenoid valve to reset to the initial closed state.

[0013] A third aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the pressure control method for the nozzle cleaning device.

[0014] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the pressure control method for the nozzle cleaning device described above.

[0015] In summary, the pressure control method, device, electronic equipment, and storage medium for the nozzle cleaning device provided in this application have at least one of the following beneficial effects: 1. A pressure sensor is installed between the three-way venting solenoid valve and the nozzle cleaning interface to continuously collect the real-time cleaning pressure of the first nozzle and compare it with the pressure fluctuation range in real time to obtain the deviation value between the actual pressure and the target pressure. This establishes a real-time pressure detection + closed-loop feedback mechanism, enabling the control card to accurately grasp the real pressure of the pipeline and completely eliminate the "pressure deviation caused by relying solely on preset drive parameters", ensuring that the actual cleaning pressure always matches the target pressure. 2. By classifying the deviation value, the pressure deviation status is determined, and the direction of pressure deviation is predicted by combining the trend of deviation value changes. Pressure anomalies can be identified in real time: continuously high pressure corresponds to ink suction pad blockage, and continuously low pressure corresponds to ink pump performance degradation or pipeline leakage. This achieves automatic perception and accurate judgment of pressure anomalies, eliminating the need for manual inspection and solving the defect of "undetectable changes in operating conditions". 3. Based on the pressure deviation status and direction, the ink pump motor drive power and the pressure relief action of the three-way venting solenoid valve are adjusted in a coordinated manner: when there is slight overpressure / underpressure, feedforward pressure suppression / pressure replenishment is used; when there is critical overpressure / underpressure, precise pressure relief / intensified pressure boosting is used, so that the real-time pressure quickly returns to and stabilizes within the allowable pressure fluctuation range, avoiding excessive pressure that could damage the nozzle and excessive pressure that could leave ink stains. This achieves a precise match between cleaning power and printhead requirements, protecting the printhead and extending its service life while ensuring cleaning effect. 4. At the end of the cleaning process, a gradient power reduction and segmented micro-pressure relief are used to reduce the pressure to atmospheric pressure before stopping the machine and resetting the solenoid valve. This avoids sudden pressure changes that could impact the pipeline and nozzle, eliminates residual pressure, and further improves the stability and safety of the system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a nozzle cleaning device shown in an embodiment of this application; Figure 2 This is a schematic flowchart illustrating a pressure control method for a nozzle cleaning device according to an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electronic device shown in an embodiment of this application. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] The following will clearly and completely describe the concept, specific structure, and technical effects of the present invention in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. Furthermore, all connections / linkages involved in the patent do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. The various technical features in this invention can be combined interactively without contradicting each other.

[0019] Reference Figure 1The diagram shown is a schematic representation of a printhead cleaning device according to an embodiment of this application. The printhead cleaning device includes an ink pump motor, a three-way venting solenoid valve, a pressure sensor, a control card, supporting pipelines, and a waste ink collection box.

[0020] The ink pump motor serves as the cleaning power source, outputting stable fluid power (positive or negative pressure) to drive the cleaning fluid or negative pressure ink suction airflow along the pipeline to the printhead cleaning interface, providing basic pressure for printhead cleaning. The three-way venting solenoid valve receives electrical signals from the control card and dynamically adjusts the output pressure in the matching pipeline by opening / closing the pressure release channel. The three-way venting solenoid valve has a three-way structure with three interfaces: the first interface, the second interface, and the third interface. The first interface connects to the output terminal of the ink pump motor; the second interface connects to the input terminal of the pressure sensor; and the third interface connects to the pressure release channel leading to the waste ink collection box.

[0021] The pressure sensor acquires the actual pressure of the cleaning medium in the pipeline in real time and continuously transmits the pressure signal to the control card. The pressure sensor integrates a pressure display gauge, which is installed on the matching pipeline between the three-way venting solenoid valve and the nozzle cleaning interface. The range is 0-60 kPa, the detection accuracy is ±0.01 kPa, and it has both real-time digital pressure display and electrical signal output functions. The output signal is a 4-20mA analog signal.

[0022] The control card is a PLC control card adapted to industrial printing equipment. It has pre-stored the printhead cleaning target pressure and the allowable pressure fluctuation range. The control card is used to receive the real-time pressure signal transmitted by the pressure sensor, compare and analyze it with the preset threshold, and output the corresponding control signal according to the comparison result to drive the three-way venting solenoid valve to perform the corresponding action, thereby forming a pressure closed-loop control circuit.

[0023] The supporting pipeline is made of corrosion-resistant material and is used to connect the core components of the nozzle cleaning device to achieve stable delivery of the cleaning medium. It effectively avoids the decrease in pressure control accuracy due to pipeline leakage and ensures the stability and reliability of the pressure control process of the entire cleaning device.

[0024] By linking the pressure sensor with the three-way venting solenoid valve, the cleaning pressure is kept constant and controllable, reducing secondary damage to the printhead, improving cleaning stability and equipment maintenance efficiency, and adapting to the cleaning needs of various inkjet printheads.

[0025] The control card is built into the electronic device. The following embodiments all use the control card as the executing entity to describe in detail the pressure control method of the nozzle cleaning device. (Refer to...) Figure 2 The diagram shown is a flowchart illustrating a pressure control method for a nozzle cleaning device according to an embodiment of this application. The pressure control method for the nozzle cleaning device includes the following steps.

[0026] S21, when a cleaning process start signal is received, the ink pump motor is started according to the preset printhead cleaning target pressure to deliver cleaning medium to the matching pipeline, so that the ink suction pad at the printhead cleaning interface can perform printhead cleaning.

[0027] In some embodiments, the control card can preset parameters such as the nozzle cleaning target pressure (hereinafter referred to as target pressure), the allowable pressure fluctuation range, the pressure deviation grading threshold, and the cleaning time. For example, the target pressure is set to 30 kPa, the allowable pressure fluctuation range is 29.99 kPa to 30.01 kPa, the upper limit of fluctuation is 30.01 kPa, and the lower limit of fluctuation is 29.99 kPa.

[0028] To facilitate understanding of the inventive concept of this application, the following embodiments are all illustrated with the target pressure P0=0kPa, the allowable pressure fluctuation range of 29.99 kPa to 30.01 kPa, the upper limit of fluctuation = 30.01 kPa, and the lower limit of fluctuation = 29.99 kPa.

[0029] When the control card receives an external signal to start the cleaning process, it immediately enters the cleaning startup execution process. Based on the preset printhead cleaning target pressure parameters, the control card outputs a corresponding drive control signal to the ink pump motor, controlling the ink pump motor to start operation at an initial power matching the target pressure. After starting, the ink pump motor generates stable fluid power, driving the cleaning medium along the matching pipeline to the three-way vent solenoid valve, pressure sensor, and finally to the printhead cleaning interface. This ensures that the cleaning medium fully adheres to the ink-absorbing pad at the printhead cleaning interface, continuously drawing ink and cleaning the printhead under a stable pressure supply.

[0030] S22, obtain the real-time cleaning pressure of the first nozzle in the matching pipeline collected by the pressure sensor.

[0031] During the cleaning process, the pressure sensor continuously collects the cleaning pressure in the supporting pipeline to obtain the real-time cleaning pressure of the nozzle (for easy distinction, it is called the real-time cleaning pressure of the first nozzle, and will be referred to as real-time pressure from now on). The pressure is then displayed digitally on the pressure display for easy manual viewing.

[0032] Meanwhile, the pressure sensor continuously transmits the real-time pressure to the control card in the form of an electrical signal, so the control card can obtain the real-time pressure collected by the pressure sensor.

[0033] S23, determine whether the real-time cleaning pressure of the first nozzle is within the allowable pressure fluctuation range.

[0034] When the control card obtains the real-time pressure, it compares the real-time pressure with the allowable pressure fluctuation range to determine whether the real-time pressure is between the upper and lower limits of the fluctuation. If it is within the allowable fluctuation range, the current drive power of the ink pump motor and the current state of the three-way venting solenoid valve remain unchanged.

[0035] S24, when it is determined that the real-time pressure of the first nozzle cleaning is not within the allowable pressure fluctuation range, calculate the deviation between the real-time pressure of the first nozzle cleaning and the target pressure of the nozzle cleaning.

[0036] When the real-time pressure is determined to exceed the allowable pressure fluctuation range, the control card calculates the deviation value ΔP=P−P0 between the real-time pressure and the target pressure, where P is the real-time pressure.

[0037] S25, determine the pressure deviation state according to the deviation value, and predict the direction of pressure deviation based on the actual change trend of the deviation value.

[0038] The control card classifies the current pipeline pressure based on the real-time calculated deviation value ΔP, determining the corresponding pressure deviation state. Simultaneously, it continuously collects multiple sets of deviation value data within a fixed time window, predicting the direction of pressure deviation based on the continuous trend of the deviation value. The pressure deviation states include slight overpressure, slight underpressure, critical overpressure, and critical underpressure. The direction of pressure deviation includes an upward trend, a downward trend, and a steady-state with no deviation. Specifically, when the real-time pressure P satisfies 30 kPa < P < 30.01 kPa, the control card determines the pressure deviation state as slight overpressure; when the real-time pressure P satisfies 29.99 kPa < P < 30 kPa, the control card determines the pressure deviation state as slight underpressure; when the real-time pressure P for the first nozzle cleaning satisfies P ≥ 30.01 kPa, the control card determines the pressure deviation state as critical overpressure; and when the real-time pressure P for the first nozzle cleaning satisfies P ≤ 29.99 kPa, the control card determines the pressure deviation state as critical underpressure. Simultaneously, the control card collects and records multiple sets of deviation values ​​ΔP in continuous first preset time periods (e.g., XX). When the deviation values ​​ΔP collected within the continuous first preset time period show an overall increasing trend, it indicates that the real-time pressure is continuously rising and deviating from the target pressure. The control card determines that the pressure deviation direction is upward. When the deviation values ​​ΔP collected within the continuous first preset time period show an overall decreasing trend, it indicates that the real-time pressure is continuously decreasing and deviating from the target pressure. The control card determines that the pressure deviation direction is downward. When the deviation values ​​ΔP collected within the continuous first preset time period remain basically unchanged without significant increase or decrease, it indicates that the pipeline pressure is in a stable state. The control card determines that the pressure deviation direction is in a steady-state state with no deviation.

[0039] By combining graded judgment of deviation state with trend prediction, the control card can identify pressure change trends in advance, avoid pressure regulation lag or overshoot, and achieve more stable and accurate pressure closed-loop control.

[0040] S26, based on the pressure deviation state and the direction of the pressure deviation, adjust the drive power of the ink pump motor and the pressure relief action of the three-way venting solenoid valve so that the real-time pressure of the first printhead cleaning returns to and stabilizes within the allowable pressure fluctuation range.

[0041] When the pressure deviation status and direction are obtained, the control card can adopt a graded adjustment strategy to coordinate the control of the ink pump motor drive power and the pressure relief action of the three-way venting solenoid valve, so that the deviated real-time pressure quickly returns to the allowable pressure fluctuation range and remains stable.

[0042] In an optional implementation, adjusting the ink pump motor drive power and the three-way venting solenoid valve's pressure relief action based on the pressure deviation state and direction, so that the real-time pressure of the first printhead cleaning returns to and stabilizes within the allowable pressure fluctuation range, includes: When the pressure deviation is determined to be a slight overpressure state and the pressure deviation direction is upward, the driving power of the ink pump motor is reduced to suppress the pressure forward, and the three-way venting solenoid valve is controlled to be in a slightly open standby state. When the pressure deviation is determined to be a slight underpressure state and the pressure deviation direction is downward, the drive power of the ink pump motor is increased to perform feedforward pressure compensation, and the three-way venting solenoid valve is controlled to be in a fully closed state. When the pressure deviation is determined to be an overpressure critical state and the pressure deviation direction is a continuous upward trend, the three-way venting solenoid valve is controlled to open the pressure release channel to release the pressure of the supporting pipeline according to the pre-stored pressure relief duration-pressure drop curve, until the real-time pressure of the nozzle cleaning returns to the pressure fluctuation range; the pressure relief duration-pressure drop curve is a pre-calibrated and stored one-to-one correspondence curve between the pressure relief duration of a single opening of the three-way venting solenoid valve and the pressure drop in the supporting pipeline; When the pressure deviation is determined to be a critical underpressure state and the pressure deviation direction is a continuous downward trend, the three-way venting solenoid valve is controlled to keep the pressure release channel closed, and the ink pump motor drive power is controlled to increase to boost the pressure until the real-time pressure of the printhead cleaning rises back to the allowable pressure fluctuation range.

[0043] (1) Mild overpressure + upward trend.

[0044] In some embodiments, when the control card determines that the real-time pressure P satisfies P0 < P < 30.01 kPa, i.e., it is in a state of slight overpressure, and simultaneously determines that the pressure deviation direction is upward based on the continuously increasing trend of the deviation value ΔP within a continuous first preset time period, the feedforward pressure suppression control process is immediately initiated. This process coordinates the adjustment of the ink pump motor drive power and the working state of the three-way venting solenoid valve to suppress the upward trend of pipeline pressure in advance, preventing the pressure from rapidly exceeding the upper limit of the allowable pressure fluctuation and entering the critical overpressure state. Specifically, the control card calculates the corresponding reduction in ink pump motor drive power based on the magnitude of the current deviation value ΔP and the rate of increase of the deviation value per unit time. This reduction is positively correlated with the deviation value and the rate of increase; that is, the larger the deviation value and the faster the rate of increase, the greater the power reduction, ensuring that the pressure suppression response speed and adjustment intensity accurately match the pressure change trend. The control card outputs the calculated target drive power signal to the ink pump motor drive module in real time, driving the ink pump motor to reduce the current operating power to the target power in a very short time. By reducing the output power of the ink pump motor, the amount of cleaning medium input into the matching pipeline is reduced from the source, thereby directly weakening the driving force for the continuous rise in pressure in the pipeline and suppressing the pressure rise trend at the source.

[0045] While reducing the drive power of the ink pump motor, the control card simultaneously outputs a solenoid valve control signal, switching the three-way venting solenoid valve from its initial fully closed state to a micro-open standby state. The micro-open standby state maintains the solenoid valve port at a very small opening, ensuring that the pipeline pressure is not significantly released, thus maintaining the continuity and effectiveness of the current cleaning operation. It also keeps the solenoid valve spool in a pre-action position, significantly shortening the response time after receiving a pressure relief command, achieving millisecond-level rapid opening. By placing the solenoid valve in micro-open standby mode, it can immediately initiate a full pressure relief action when the pipeline pressure approaches or reaches the 30.01 kPa fluctuation limit, without waiting for the valve spool to complete its full stroke. This significantly improves the timeliness and stability of pressure regulation, avoiding pressure overshoot shocks.

[0046] During the feedforward pressure suppression process, the control card continues to acquire real-time pressure and deviation data using high-frequency sampling to monitor the feedforward pressure suppression effect in real time. If the deviation value ΔP gradually decreases, the upward pressure trend is suppressed, and it approaches the target pressure P0, the control card maintains the current ink pump motor power and solenoid valve status unchanged until the real-time pressure stabilizes and returns to near the target pressure. If the pressure continues to rise after feedforward pressure suppression and is about to exceed 30.01 kPa, the control card immediately switches the control logic and initiates the pressure relief process according to the overpressure critical state adjustment strategy, thus forming a dual-layer protection mechanism of "feedforward pressure suppression + rapid pressure relief" to ensure that the cleaning pressure is maintained stably within the allowable pressure fluctuation range throughout the process, ensuring sufficient cleaning power while avoiding damage to the printhead caused by abnormal pressure.

[0047] (2) Mild undervoltage + downward trend.

[0048] When the control card determines that the real-time pressure P of the first printhead cleaning meets the condition of 29.99 kPa < P < P0, indicating a slight underpressure state, and simultaneously determines that the pressure deviation is trending upward based on the continuously increasing deviation value ΔP over the first preset time period, the feedforward pressure suppression control process is immediately initiated. This process coordinates the adjustment of the ink pump motor drive power and the operating status of the three-way venting solenoid valve to suppress the upward pressure trend in the pipeline, preventing the pressure from rapidly exceeding the upper limit of the allowable pressure fluctuation and entering an overpressure critical state. Specifically, the control card calculates the corresponding reduction in ink pump motor drive power based on the magnitude of the current deviation value ΔP and its rate of increase per unit time. This reduction is positively correlated with the deviation value and the rate of increase; that is, the larger the deviation value and the faster the rate of increase, the greater the power reduction, ensuring that the pressure suppression response speed and adjustment intensity accurately match the pressure change trend. The control card outputs the calculated target drive power signal to the ink pump motor drive module in real time, driving the ink pump motor to reduce the current operating power to the target power in a very short time. By reducing the output power of the ink pump motor, the amount of cleaning medium input into the matching pipeline is reduced from the source, thereby directly weakening the driving force for the continuous rise in pressure in the pipeline and suppressing the pressure rise trend at the source.

[0049] Specifically, the control card calculates the corresponding increase in the ink pump motor drive power based on the absolute value of the current deviation ΔP and the rate of decrease of the deviation per unit time. This increase is positively correlated with the absolute value of the deviation and the rate of pressure decrease; that is, the greater the current underpressure and the faster the pressure decreases, the greater the power increase. This ensures that the pressure compensation response speed and adjustment intensity can accurately match the pressure decay trend, achieving rapid, stable, and overshoot-free pressure compensation. The control card outputs the calculated target drive power signal to the ink pump motor drive module in real time, driving the ink pump motor to smoothly increase the current operating power to the target power within a preset response time. By increasing the output power of the ink pump motor, the flow rate and output pressure of the cleaning medium into the matching pipeline are increased from the source, directly strengthening the pressure replenishment capacity in the pipeline. This achieves source suppression and rapid rise of the pressure decline trend, allowing the real-time pressure to approach the target pressure P0 as quickly as possible.

[0050] While increasing the ink pump motor drive power, the control card continuously outputs a command to keep the solenoid valve closed, ensuring the three-way venting solenoid valve remains fully closed. This guarantees a tight seal on the pressure release channel, preventing unnecessary pressure loss through the venting channel. The fully closed state ensures that the increased pressure generated by the increased ink pump motor power is applied entirely to the effective working range of the printhead cleaning end, maximizing pressure replenishment efficiency and preventing further pressure loss due to solenoid valve leaks or malfunctions, thus guaranteeing the effectiveness of the feedforward pressure replenishment operation.

[0051] During the feedforward pressure replenishment process, the control card continues to acquire real-time pressure data and update the deviation value ΔP using a high-frequency sampling mode, monitoring the pressure replenishment effect and pressure change trend in real time. If the deviation value ΔP gradually increases, the pressure drop trend is effectively suppressed, and it shows a trend of rising back towards the target pressure P0, the control card maintains the current ink pump motor drive power and the solenoid valve closed state until the real-time pressure stabilizes and returns to near the target pressure. If the pressure continues to drop after feedforward pressure replenishment and is about to fall below 29.99 kPa, the control card immediately switches the control logic and executes the enhanced pressure boosting process according to the underpressure critical state adjustment strategy, thus forming a dual-layer protection mechanism of "feedforward pressure replenishment + enhanced pressure boosting" to ensure that the cleaning pressure is maintained stably within the allowable pressure fluctuation range throughout the process, ensuring sufficient and reliable cleaning power while avoiding problems such as incomplete cleaning and ink residue clogging of the printhead due to insufficient pressure.

[0052] (3) Overpressure critical state + upward trend.

[0053] When the control card determines that the real-time cleaning pressure P of the first nozzle meets the condition of P≥30.01 kPa, i.e. it is in an overpressure critical state, and when the deviation value ΔP continuously increases within the first preset time period, indicating that the pressure deviation direction is continuously rising, the precise pressure relief control process is immediately initiated. The pressure relief duration-pressure drop curve is used to achieve rapid and stable pressure relief in the pipeline, avoiding damage to the nozzle and internal flow channel caused by continuous pressure increase, and ensuring that the cleaning pressure quickly returns to the allowable pressure fluctuation range.

[0054] Specifically, the control card uses the difference between the current real-time pressure and the upper limit of the allowable pressure fluctuation (30.01 kPa), along with the rate of pressure increase per unit time, to retrieve a pre-stored pressure relief duration-pressure drop curve for matching calculation. This curve was obtained through multiple calibrations under no-load and load conditions before leaving the factory, recording a one-to-one correspondence between the pressure relief duration of a single opening of the three-way venting solenoid valve and the pressure drop of the matching pipeline, ensuring precise matching between the pressure relief amplitude and the current pressure overshoot. Based on the curve, the control card determines the optimal pressure relief duration and outputs the corresponding solenoid valve drive signal to the valve control module in real time, driving the three-way venting solenoid valve to open the pressure release channel for the set duration. This smoothly releases excessive pressure in the pipeline to the waste ink collection box, rapidly reducing pipeline pressure through the pressure relief channel and suppressing the continuous pressure rise.

[0055] While performing the pressure relief operation, the control card maintains real-time monitoring and dynamic adaptation of the ink pump motor drive power, and synchronously fine-tunes the motor output according to the pressure drop rate to avoid large pressure fluctuations due to excessively rapid pressure relief. Through precise pressure relief calibrated by the curve, the overpressure state can be quickly corrected to the normal range without impacting the pipeline or affecting the continuity of cleaning.

[0056] During precise pressure relief, the control card continuously acquires real-time pressure and deviation data using high-frequency sampling to monitor the pressure relief effect. When the real-time pressure drops to the allowable fluctuation range of 29.99 kPa to 30.01 kPa, the control card immediately closes the three-way venting solenoid valve, restoring it to its initial closed state. If the pressure drop is slow, the control card can perform short-term supplementary pressure relief again according to the curve until the pressure is completely stable within the target range. This forms a dual guarantee mechanism of "curve-matched pressure relief + real-time closed-loop correction," ensuring that the pipeline pressure quickly and smoothly recovers to the allowable range, guaranteeing both stable cleaning power and safety protection for the nozzles.

[0057] (4) Undervoltage critical state + downward trend.

[0058] When the control card determines that the real-time pressure P of the first printhead cleaning meets P≤29.99 kPa, i.e. it is in a critical state of underpressure, and based on the continuous decreasing trend of the deviation value ΔP within the first preset time period, it determines that the pressure deviation direction is continuously decreasing, and immediately starts the enhanced pressure boosting control process. Through the coordinated action of closing the pressure relief channel and increasing the power of the ink pump motor, it quickly makes up for the insufficient pipeline pressure, avoids problems such as incomplete cleaning and printhead residue blockage caused by continuously low pressure, and ensures that the cleaning pressure quickly rises to the allowable pressure fluctuation range.

[0059] Specifically, the control card first keeps the three-way venting solenoid valve completely closed, tightly sealing the pressure release channel to prevent further pressure loss through the venting channel. This ensures that all the fluid power output from the ink pump motor is applied to the printhead cleaning end, maximizing pressurization efficiency. Based on this, the control card calculates the required increase in ink pump motor drive power based on the absolute value of the current deviation and the pressure drop rate. This increase is greater than in the feedforward pressurization mode, rapidly increasing the cleaning medium flow rate and output pressure, forcibly raising the pipeline pressure from the power source and preventing further pressure drop.

[0060] The control card outputs the calculated target drive power signal to the ink pump motor drive module in real time, driving the ink pump motor to increase its operating power to the target value in a short time, significantly enhancing the pipeline pressure replenishment capability, realizing the rapid reversal of the underpressure trend, and making the real-time pressure approach the target pressure P0 as soon as possible.

[0061] During the enhanced pressurization process, the control card continues to collect real-time pressure data in a high-frequency sampling mode, dynamically monitoring the pressure recovery rate and deviation changes. When the real-time pressure recovers to the allowable pressure fluctuation range of 29.99 kPa to 30.01 kPa, the control card gradually reduces the ink pump motor power to the normal maintenance power to stabilize the pressure within the target range. If the pressure recovery is slow, the control card can further slightly increase the power to accelerate the pressurization speed until the pressure is completely stable. This forms a dual guarantee mechanism of "closed pressure maintenance + enhanced pressurization," ensuring that the pipeline pressure recovers quickly and smoothly to the allowable range, guaranteeing sufficient, stable, and reliable cleaning power.

[0062] Through the aforementioned optional implementation methods, the control card can perform graded, precise, and adaptive coordinated adjustment based on the pressure deviation state and direction. This suppresses pressure fluctuations at the source, quickly corrects pressure deviations, and ensures that the real-time pressure of the first printhead cleaning quickly returns to and stabilizes within the allowable pressure fluctuation range of 29.99 kPa to 30.01 kPa, truly achieving closed-loop constant control of the cleaning pressure. This adjustment method avoids both excessive pressure causing printhead nozzle diaphragm rupture and internal flow channel damage, and excessive pressure leading to incomplete cleaning and ink residue clogging the printhead. It also balances adjustment response speed and operational stability, significantly improving the safety, effectiveness, and operational stability of printhead cleaning.

[0063] In an optional implementation, the method further includes: Calculate the fluid resistance value Z in the supporting pipeline, Z=(Pin-Pout) / Q, where Pin is the outlet pressure of the three-way venting solenoid valve, Pout is the pressure at the nozzle cleaning interface, and Q is the real-time flow rate of the cleaning medium in the supporting pipeline. Based on the deviation rate between the impedance value and the reference impedance value, the power adjustment range of the ink pump motor and the depressurization time of the three-way venting solenoid valve are dynamically corrected; including: when the fluid impedance value is greater than the reference impedance value, increasing the power adjustment range of the ink pump motor and shortening the single depressurization time of the three-way venting solenoid valve; when the fluid impedance value is less than the reference impedance value, decreasing the power adjustment range of the ink pump motor and extending the single depressurization time of the three-way venting solenoid valve; the reference impedance value is the initial pipeline impedance value obtained by the no-load calibration of the printhead cleaning device.

[0064] In some embodiments, during the entire closed-loop control process of the cleaning pressure, fluid impedance calculation and dynamic correction are performed synchronously before the control card executes the ink pump motor power adjustment and the three-way venting solenoid valve pressure relief action. This is used to eliminate pressure control deviations caused by factors such as changes in medium viscosity, slight blockage in pipelines, aging of ink suction pads, and changes in printhead bonding gap in real time, thereby further improving the accuracy and stability of pressure regulation.

[0065] Specifically, during the factory commissioning phase of the nozzle cleaning device, the supporting pipeline is calibrated in advance under no-load conditions to obtain a reference impedance value Z0. This reference impedance value Z0 is the initial impedance parameter of the pipeline when there is no load, no blockage, and no leakage, and is stored in the control card as a subsequent comparison benchmark. After the cleaning process starts and during real-time pressure adjustment, the control card collects relevant parameters in real time and calculates the fluid impedance value Z in the current supporting pipeline. The calculation formula is: Z=(Pin-Pout) / Q, where Pin is the outlet pressure of the three-way venting solenoid valve, Pout is the pressure at the nozzle cleaning interface, and Q is the real-time flow rate of the cleaning medium in the supporting pipeline.

[0066] The control card compares the real-time calculated fluid resistance value Z with the reference resistance value Z0, calculates the deviation rate between the two, and dynamically adjusts the power adjustment range of the subsequent ink pump motor and the single pressure relief duration of the three-way venting solenoid valve based on the magnitude of the deviation rate, so that the pressure regulation strategy adaptively matches the actual operating conditions of the current pipeline. The specific correction rules are as follows: When the fluid resistance value Z is greater than the reference resistance value Z0, it indicates an increase in flow resistance within the piping, which may be due to minor blockage, increased medium viscosity, or compaction of the ink-absorbing pad. In this case, the piping becomes more sensitive to pressure changes. The control card automatically increases the power adjustment range of the ink pump motor, enabling faster response and higher adjustment intensity during pressure suppression, replenishment, and boosting processes. Simultaneously, it shortens the single pressure relief time of the three-way venting solenoid valve, preventing excessive pressure drop due to prolonged relief time and ensuring more precise and stable pressure relief.

[0067] When the fluid resistance value Z0 is less than the reference resistance value Z0, it indicates that the internal flow resistance of the matching pipeline has decreased, which may be due to pipeline loosening, increased leakage tendency, or excessive printhead contact gap. In this case, the pipeline pressure holding capacity weakens. The control card automatically reduces the power adjustment range of the ink pump motor to avoid pressure overshoot caused by excessive adjustment range; at the same time, it extends the single pressure relief time of the three-way venting solenoid valve to ensure sufficient pressure relief range, so that the pressure can stably fall back to the target range.

[0068] By calculating fluid impedance and dynamically correcting parameters in real time before each power adjustment and pressure relief action, the entire pressure closed-loop control system can be made to have the ability to adapt to operating conditions, significantly improving the stability of pressure control under different operating environments and different aging levels, and further ensuring the cleaning effect of the nozzles and the service life of the equipment.

[0069] S27, when the preset cleaning time is met, control the ink pump motor to stop working and control the three-way venting solenoid valve to reset to the initial closed state.

[0070] When the real-time timer reaches the preset cleaning duration, the control card determines that the printhead cleaning process is complete and immediately executes the cleaning end control operation. The control card simultaneously outputs a shutdown control signal and a reset control signal. On one hand, it controls the ink pump motor to immediately stop power output, ceasing the delivery of cleaning media into the pipeline and terminating the printhead cleaning action. On the other hand, it controls the three-way venting solenoid valve to reset to its initial closed state, sealing the pressure release channel and preventing leakage of residual media in the pipeline. By simultaneously executing the shutdown of the ink pump motor and the reset of the solenoid valve, the cleaning process is ensured to be completed correctly, and the pipeline and all actuators return to their initial standby state, preparing for the next printhead cleaning process while ensuring the safe and stable operation of the equipment.

[0071] In an optional implementation, before controlling the ink pump motor to stop operating when the preset cleaning time is met, the method further includes: The ink pump motor is controlled to perform a gradient power reduction operation, which reduces the driving power of the ink pump motor from the normal working power adapted to the printhead cleaning target pressure according to a preset decreasing gradient, and continuously acquires the real-time pressure of the second printhead cleaning collected by the pressure sensor during the gradient power reduction process. When the real-time pressure of the second nozzle cleaning drops to a preset ratio of the target pressure of the nozzle cleaning, the three-way venting solenoid valve is controlled to open at a preset micro-opening degree to release pressure on the supporting pipeline, and the real-time pressure of the third nozzle cleaning collected by the pressure sensor is continuously acquired during the pressure release process. When the real-time cleaning pressure of the third printhead drops to the normal pressure range, the ink pump motor is controlled to completely stop working, and the three-way venting solenoid valve is controlled to reset to the initial closed state; wherein, the normal pressure range is the environmental pressure range when there is no cleaning medium being transported in the supporting pipeline.

[0072] In some embodiments, when the preset cleaning time is about to end, the control card performs a gradient power reduction operation on the ink pump motor. After reaching a preset proportional pressure, the solenoid valve is activated to slightly open and release pressure. After the pressure drops to normal, the machine stops and the solenoid valve resets. Specifically, the control card controls the ink pump motor to perform a gradient power reduction operation, gradually and smoothly reducing the ink pump motor drive power from the current normal operating power adapted to the target pressure in stages according to a preset reduction gradient. Throughout the gradient power reduction process, the control card continuously acquires the real-time printhead cleaning pressure collected by the pressure sensor (referred to as the second printhead cleaning real-time pressure for easy distinction), and continuously monitors the pipeline pressure changes to ensure that the power reduction process is smooth, without pressure sudden changes, and without shocks. The control card continuously compares the second printhead cleaning real-time pressure with the printhead cleaning target pressure. When the second printhead cleaning real-time pressure is detected to drop to a preset proportion of the printhead cleaning target pressure, a control command is immediately output to control the three-way venting solenoid valve to open stably at a preset micro-opening degree, performing slow pressure relief on the associated pipeline. During the pressure relief process, the control card continuously acquires the real-time printhead cleaning pressure collected by the pressure sensor (referred to as the third printhead cleaning real-time pressure for easy distinction), and tracks the pressure drop in the pipeline in real time to ensure a smooth and controllable pressure relief process. Next, the control card continuously determines whether the third printhead cleaning real-time pressure falls within the normal pressure range, which is the ambient pressure range when no cleaning medium is being transported in the supporting pipeline. When the third printhead cleaning real-time pressure is detected to have dropped to the normal pressure range, the control card immediately controls the ink pump motor to completely stop working, and simultaneously outputs a reset command to control the three-way venting solenoid valve to reset to its initial closed state, completing the pressure closed-loop termination and component reset operation of the entire cleaning process.

[0073] Through the above optional implementation methods, the cleaning process can be smoothly completed by gradient power reduction and segmented slow pressure relief, avoiding sudden pressure changes that could impact the nozzle; real-time pressure monitoring throughout the process ensures that pressure relief is gradual and controllable, protecting pipelines and components; and shutdown and reset after reducing to atmospheric pressure can eliminate residual pressure, improving the stability and service life of the device.

[0074] In an optional implementation, the method further includes: When the real-time pressure of the nozzle cleaning is within the pressure abnormality alarm threshold range for a continuous second preset time period, a pressure abnormality alarm signal is generated; the pressure abnormality alarm threshold range includes an upper limit and a lower limit of the pressure abnormality alarm threshold. The faulty component is located based on the type of pressure anomaly. The pressure anomaly types include overpressure anomaly and underpressure anomaly. When the real-time pressure of the printhead cleaning is higher than the upper limit of the pressure anomaly alarm threshold for a continuous second preset time period, the faulty component is determined to be the ink suction pad. When the real-time pressure of the printhead cleaning is lower than the lower limit of the pressure anomaly alarm threshold for a continuous second preset time period, the faulty component is determined to be the ink pump motor or its supporting pipeline.

[0075] In some embodiments, throughout the entire nozzle cleaning process, the control card continuously acquires real-time nozzle cleaning pressure data from pressure sensors in a high-frequency sampling mode, and continuously compares the real-time pressure with a preset pressure anomaly alarm threshold range. The pressure anomaly alarm threshold range consists of an upper limit and a lower limit, calibrated based on the nozzle cleaning target pressure and the allowable pressure fluctuation range, used to determine whether the cleaning pressure deviates from the normal operating range for an extended period. When the control card determines that the real-time nozzle cleaning pressure remains within the pressure anomaly alarm threshold range for a continuous second preset time period, it immediately initiates the pressure anomaly monitoring and fault location process, generating and outputting a pressure anomaly alarm signal to notify on-site personnel via audible and visual alarms or equipment interface prompts, achieving real-time early warning and rapid response to faults.

[0076] While outputting alarm signals, the control card determines the type of pressure anomaly based on the abnormal range of the real-time pressure and further locates the corresponding faulty component, achieving accurate identification of the cause of the fault. The pressure anomaly alarm threshold range includes an upper limit and a lower limit. Specifically, when the real-time pressure of the printhead cleaning device is higher than the upper limit of the pressure anomaly alarm threshold for a continuous second preset time period, the control card determines the current pressure anomaly type as an overpressure anomaly. Combining the working mechanism of the cleaning device and the pipeline pressure change pattern, it further determines that the overpressure anomaly is caused by a clogged ink-absorbing pad, i.e., the faulty component is the ink-absorbing pad. A clogged ink-absorbing pad leads to poor flow of the cleaning medium, causing a continuous increase in internal pipeline pressure, which in turn causes the real-time pressure to exceed the alarm upper limit for an extended period. This determination rule directly identifies the clogged fault.

[0077] When the printhead cleaning real-time pressure remains below the lower limit of the pressure anomaly alarm threshold for a consecutive second preset time period, the control card determines the current pressure anomaly type as underpressure. Combining this with the system's power supply and pipeline sealing characteristics, it further determines that the underpressure anomaly is caused by insufficient output power from the ink pump motor or by sealing failure or leakage in the supporting pipeline; that is, the faulty component is either the ink pump motor or the supporting pipeline. Ink pump motor failure leads to insufficient pressure output, while pipeline leakage causes continuous pressure loss; both will cause the real-time pressure to remain below the alarm threshold for an extended period. Through this one-to-one correspondence between pressure anomaly types and faulty components, the control card can automatically complete fault identification and location, and simultaneously store information such as fault type, faulty component, abnormal pressure value, and anomaly occurrence time in its internal memory, forming a traceable fault record. Based on the alarm information and fault location results, staff can directly inspect, clean, or replace the corresponding components, significantly reducing the time spent on manual troubleshooting, lowering equipment maintenance costs, and improving the operational continuity and stability of the inkjet printing equipment.

[0078] The embodiments of this application can be widely applied to equipment such as industrial inkjet printers, digital printing machines, and UV printers that require regular printhead maintenance and cleaning. They enable real-time detection and constant control of cleaning pressure, balancing printhead protection and cleaning efficiency. To facilitate understanding of the inventive concept, a specific implementation method using UV printer printhead cleaning as an example is provided below.

[0079] The ink pump motor is a 50W DC motor with an adjustable output pressure range of 0-60 kPa. The three-way venting solenoid valve is a 24V normally closed type with a response time ≤0.1 seconds. The pressure sensor has a range of 0-60 kPa, a detection accuracy of ±0.01 kPa, outputs a 4-20mA analog signal, and is equipped with a digital display. The control card is an industrial-grade PLC control card. The piping uses PU material resistant to UV cleaning fluid corrosion. The ink pump motor output is connected to the first port of the three-way venting solenoid valve via corrosion-resistant piping. The second port of the solenoid valve is connected to the pressure sensor, which is then connected to the printhead cleaning port. The third port of the solenoid valve is connected to the waste ink collection box via a pressure release channel. The control card is electrically connected to the ink pump motor, the three-way venting solenoid valve, and the pressure sensor. The PLC control card sets the target cleaning pressure to 30 kPa, with an allowable pressure fluctuation range of ±0.01 kPa. The abnormal pressure alarm threshold is >30.05 kPa or <29.95 kPa, and the alarm method is audible and visual. During cleaning operation, the cleaning program is initiated, the control card drives the ink pump motor, and the pressure sensor collects and uploads the pipeline pressure in real time. When the pressure exceeds the upper limit, the solenoid valve briefly releases pressure; when the pressure falls below the lower limit, the solenoid valve remains closed to increase pressure, maintaining a stable pressure in a cycle. After the cleaning time is reached, the ink pump motor shuts down, and the solenoid valve resets. During the fault handling phase, if the pressure remains excessively high, an alarm is triggered indicating ink suction pad blockage; if the pressure remains excessively low, it indicates ink pump failure or pipeline leakage. After the staff investigates and repairs, the equipment can return to normal operation.

[0080] See Figure 3 The diagram shown is a schematic representation of the structure of an electronic device according to an embodiment of this application. In a preferred embodiment of this application, the electronic device 3 includes a memory 31, at least one processor 32, and at least one communication bus 33.

[0081] Those skilled in the art should understand that Figure 3 The structure of the electronic device shown does not constitute a limitation of the embodiments of this application. It can be a bus structure or a star structure. The electronic device 3 may also include more or fewer other hardware or software than shown, or different component arrangements.

[0082] In some embodiments, the electronic device 3 is a device capable of automatically performing numerical calculations and / or information processing according to pre-set or stored instructions. Its hardware includes, but is not limited to, microprocessors, application-specific integrated circuits (ASICs), programmable gate arrays (FPGAs), digital processors, and embedded devices. The electronic device 3 may also include user equipment, which includes, but is not limited to, any electronic product capable of human-computer interaction with a user via a keyboard, mouse, remote control, touchpad, or voice control device, such as a personal computer, tablet computer, smartphone, or digital camera.

[0083] In the embodiments provided in this application, it should be understood that the disclosed methods, apparatuses, computer-readable storage media, and electronic devices can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple components or modules may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices, components, or modules may be electrical, mechanical, or other forms.

[0084] The components described as separate parts may or may not be physically separate. The components shown as components may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the components can be selected to achieve the purpose of this embodiment according to actual needs.

[0085] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each component can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0086] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0087] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0088] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0089] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A pressure control method for a nozzle cleaning device, characterized in that, The control card is applied to the printhead cleaning device, which also includes an ink pump motor, a pressure sensor, a three-way venting solenoid valve, matching pipes, and a waste ink collection box. The three-way venting solenoid valve has three interfaces: the first interface is connected to the output end of the ink pump motor, the second interface is connected to the input end of the pressure sensor, and the third interface is connected to the pressure release channel leading to the waste ink collection box. The pressure sensor is located on the matching pipeline between the three-way venting solenoid valve and the nozzle cleaning interface; the method includes: When a cleaning process start signal is received, the ink pump motor is started according to the preset printhead cleaning target pressure to deliver cleaning medium to the matching pipeline, so that the ink suction pad at the printhead cleaning interface can perform printhead cleaning. The pressure sensor collects the real-time cleaning pressure of the first nozzle in the matching pipeline; Determine whether the real-time cleaning pressure of the first nozzle is within the allowable pressure fluctuation range; When it is determined that the real-time pressure of the first nozzle cleaning is not within the allowable pressure fluctuation range, the deviation between the real-time pressure of the first nozzle cleaning and the target pressure of the nozzle cleaning is calculated. The pressure deviation state is determined according to the deviation value, and the direction of pressure deviation is predicted based on the actual change trend of the deviation value; Based on the pressure deviation state and the direction of the pressure deviation, adjust the drive power of the ink pump motor and the pressure relief action of the three-way venting solenoid valve so that the real-time pressure of the first printhead cleaning returns to and stabilizes within the allowable pressure fluctuation range. When the preset cleaning time is met, the ink pump motor is controlled to stop working, and the three-way venting solenoid valve is controlled to reset to the initial closed state.

2. The pressure control method for the nozzle cleaning device according to claim 1, characterized in that, The pressure deviation states include a slight overpressure state, a slight underpressure state, a critical overpressure state, and a critical underpressure state; the pressure deviation directions include an upward trend and a downward trend; adjusting the ink pump motor drive power and the three-way venting solenoid valve's pressure relief action according to the pressure deviation states and directions, so that the real-time pressure of the first printhead cleaning returns to and stabilizes within the allowable pressure fluctuation range, includes: When the pressure deviation is determined to be a slight overpressure state and the pressure deviation direction is upward, the driving power of the ink pump motor is reduced to suppress the pressure forward, and the three-way venting solenoid valve is controlled to be in a slightly open standby state. When the pressure deviation is determined to be a slight underpressure state and the pressure deviation direction is downward, the drive power of the ink pump motor is increased to perform feedforward pressure compensation, and the three-way venting solenoid valve is controlled to be in a fully closed state. When the pressure deviation is determined to be an overpressure critical state and the pressure deviation direction is a continuous upward trend, the three-way venting solenoid valve is controlled to open the pressure release channel to release the pressure of the supporting pipeline according to the pre-stored pressure relief duration-pressure drop curve, until the real-time pressure of the nozzle cleaning returns to the pressure fluctuation range; the pressure relief duration-pressure drop curve is a pre-calibrated and stored one-to-one correspondence curve between the pressure relief duration of a single opening of the three-way venting solenoid valve and the pressure drop in the supporting pipeline; When the pressure deviation is determined to be a critical underpressure state and the pressure deviation direction is a continuous downward trend, the three-way venting solenoid valve is controlled to keep the pressure release channel closed, and the ink pump motor drive power is controlled to increase to boost the pressure until the real-time pressure of the printhead cleaning rises back to the allowable pressure fluctuation range.

3. The pressure control method for the nozzle cleaning device according to claim 1, characterized in that, The step of classifying and determining the pressure deviation state based on the deviation value includes: When the real-time pressure of the first nozzle cleaning is greater than the target pressure of the nozzle cleaning but less than the upper limit of the fluctuation, the pressure deviation state is determined to be a slight overpressure state; the allowable pressure fluctuation range includes the upper limit of the fluctuation and the lower limit of the fluctuation. When the real-time pressure of the first nozzle cleaning is less than the target pressure of the nozzle cleaning but greater than the lower limit of the fluctuation, the pressure deviation state is determined to be a slightly under-pressure state. When the real-time cleaning pressure of the first nozzle is greater than or equal to the upper limit of the fluctuation, the pressure deviation state is determined to be an overpressure critical state. When the real-time cleaning pressure of the first nozzle is less than or equal to the lower limit of the fluctuation, the pressure deviation state is determined to be an underpressure critical state.

4. The pressure control method for the nozzle cleaning device according to claim 1, characterized in that, The method of predicting the direction of pressure deviation based on the actual trend of the deviation value includes: When the deviation value of the first preset time period shows an increasing trend, it is determined that the pressure is deviating from the direction away from the cleaning target pressure of the nozzle, and it is determined that the direction of pressure deviation is increasing. When the deviation value of the first preset time period shows a decreasing trend, it is determined that the pressure is deviating in the direction of approaching the nozzle cleaning target pressure, and the pressure deviation direction is determined to be decreasing. If the deviation value remains unchanged for the first preset time period, it is determined that the pressure deviation direction is in a steady state with no offset.

5. The pressure control method for the nozzle cleaning device according to claim 1, characterized in that, The method further includes: Calculate the fluid resistance value Z in the supporting pipeline, Z=(Pin−Pout) / Q, where Pin is the outlet pressure of the three-way venting solenoid valve, Pout is the pressure at the nozzle cleaning interface, and Q is the real-time flow rate of the cleaning medium in the supporting pipeline. Based on the deviation rate between the impedance value and the reference impedance value, the power adjustment range of the ink pump motor and the depressurization time of the three-way venting solenoid valve are dynamically corrected; including: when the fluid impedance value is greater than the reference impedance value, increasing the power adjustment range of the ink pump motor and shortening the single depressurization time of the three-way venting solenoid valve; when the fluid impedance value is less than the reference impedance value, decreasing the power adjustment range of the ink pump motor and extending the single depressurization time of the three-way venting solenoid valve; the reference impedance value is the initial pipeline impedance value obtained by the no-load calibration of the printhead cleaning device.

6. The pressure control method for the nozzle cleaning device according to claim 1, characterized in that, Before controlling the ink pump motor to stop working when the preset cleaning time is met, the method further includes: The ink pump motor is controlled to perform a gradient power reduction operation, which reduces the driving power of the ink pump motor from the normal working power adapted to the printhead cleaning target pressure according to a preset decreasing gradient, and continuously acquires the real-time pressure of the second printhead cleaning collected by the pressure sensor during the gradient power reduction process. When the real-time pressure of the second nozzle cleaning drops to a preset ratio of the target pressure of the nozzle cleaning, the three-way venting solenoid valve is controlled to open at a preset micro-opening degree to release pressure on the supporting pipeline, and the real-time pressure of the third nozzle cleaning collected by the pressure sensor is continuously acquired during the pressure release process. When the real-time cleaning pressure of the third printhead drops to the normal pressure range, the ink pump motor is controlled to completely stop working, and the three-way venting solenoid valve is controlled to reset to the initial closed state; wherein, the normal pressure range is the environmental pressure range when there is no cleaning medium being transported in the supporting pipeline.

7. The pressure control method for the nozzle cleaning device according to any one of claims 1 to 6, characterized in that, The method further includes: When the real-time pressure of the nozzle cleaning is within the pressure abnormality alarm threshold range for a continuous second preset time period, a pressure abnormality alarm signal is generated; the pressure abnormality alarm threshold range includes an upper limit and a lower limit of the pressure abnormality alarm threshold. The faulty component is located based on the type of pressure anomaly. The pressure anomaly types include overpressure anomaly and underpressure anomaly. When the real-time pressure of the printhead cleaning is higher than the upper limit of the pressure anomaly alarm threshold for a continuous second preset time period, the faulty component is determined to be the ink suction pad. When the real-time pressure of the printhead cleaning is lower than the lower limit of the pressure anomaly alarm threshold for a continuous second preset time period, the faulty component is determined to be the ink pump motor or its supporting pipeline.

8. A nozzle cleaning device, characterized in that, The device includes: The system includes a control card, an ink pump motor, a pressure sensor, a three-way venting solenoid valve, matching piping, and a waste ink collection box. The three-way venting solenoid valve has three interfaces: the first interface connects to the output of the ink pump motor, the second interface connects to the input of the pressure sensor, and the third interface connects to the waste ink collection box via a pressure release channel. The pressure sensor is located on the matching piping between the three-way venting solenoid valve and the printhead cleaning interface. The control card is electrically connected to the ink pump motor, the pressure sensor, and the three-way venting solenoid valve. The control card is configured to: when receiving a cleaning process start signal, control the ink pump motor to start according to the preset printhead cleaning target pressure, deliver cleaning medium to the printhead cleaning interface through the matching pipeline, and perform printhead cleaning in conjunction with the ink suction pad; acquire the real-time pressure of the first printhead cleaning in the matching pipeline collected by the pressure sensor; determine whether the real-time pressure of the first printhead cleaning is within the pressure fluctuation range; when it is not within the pressure fluctuation range, calculate the deviation value between the real-time pressure of the first printhead cleaning and the printhead cleaning target pressure; classify the pressure deviation state according to the deviation value, and predict the pressure deviation direction based on the changing trend of the deviation value; adjust the drive power of the ink pump motor and the pressure relief action of the three-way venting solenoid valve according to the pressure deviation state and the pressure deviation direction, so that the real-time pressure of the first printhead cleaning returns to and stabilizes within the pressure fluctuation range; when the preset cleaning time is met, control the ink pump motor to stop working, and control the three-way venting solenoid valve to reset to the initial closed state.

9. An electronic device, characterized in that, The device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the pressure control method for the nozzle cleaning apparatus according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the pressure control method for the nozzle cleaning device according to any one of claims 1 to 7.

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