A method for controlling ink cartridge temperature

Abstract

This application discloses a method for controlling ink cartridge temperature, relating to the field of digital printing technology, and applied to an ink cartridge device including an ink chamber, a heating chamber, a first temperature sensor, a second temperature sensor, a heating rod, and a controller. The method includes: acquiring ink temperature values ​​and heat-conducting fluid temperature values ​​in real time, as well as the printing press operating status signal; performing a safety interlock judgment on the heat-conducting fluid and ink temperature values; if either temperature value exceeds a preset threshold causing the interlock to fail, the heating rod is shut down; when the safety interlock passes, selecting a corresponding target temperature range based on the operating status signal; and controlling the heating rod's start and stop based on the ink temperature value and the target temperature range. This application, through dual-temperature monitoring and a safety interlock mechanism, effectively prevents safety hazards caused by localized overheating; and, in conjunction with the printing press operating conditions, dynamically adjusts the temperature control strategy, reducing energy consumption while ensuring ink viscosity and print quality, thereby improving equipment safety and reliability.

Description

Technical Field

[0001] This application relates to the field of digital printing technology, and in particular to a method for controlling ink cartridge temperature. Background Technology

[0002] When digital printers operate in low-temperature environments, ink viscosity increases significantly due to the drop in temperature, easily leading to serious print quality problems such as ink skipping and printhead clogging, and even ink crystallization. To solve this problem, the industry typically requires heating and maintaining a constant temperature for the ink. Traditional solutions often involve directly heating the ink, immersing the heating element directly in the ink or attaching it to the surface of the ink container. However, the surface temperature of the heating element in this direct heating structure is often high and unevenly distributed, easily causing localized overheating of the ink at the contact points, which in turn leads to denaturation of the ink's chemical composition, performance degradation, and even clumping.

[0003] However, existing indirect heating control methods still have many shortcomings. First, the existing control logic is mostly simplistic, typically relying solely on ink temperature or level for basic start-stop control, lacking effective monitoring of the temperature of the heat transfer medium itself and multi-level safety interlock mechanisms. Once localized overheating occurs in the heat transfer medium, it can easily lead to vaporization and boiling, damage to seals, and even serious safety accidents. Second, existing cartridge heating control systems typically operate independently of the printing press host, unable to dynamically adjust the temperature control strategy according to the actual operating state of the printing press (such as standby, high-speed printing, cleaning, and sleep modes). This fixed temperature control method, disconnected from the printing press's operating conditions, not only causes significant energy waste during standby or sleep modes but also fails to respond promptly to cleaning conditions that require changes in ink viscosity.

[0004] In summary, there is an urgent need in the existing technology for an ink cartridge temperature control method that can be deeply integrated with the working status of the printing press, has a complete safety interlock mechanism, and accurately controls the ink output temperature. Summary of the Invention

[0005] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a cartridge temperature control method that can improve the safety of cartridge device operation and the reliability of the equipment.

[0006] The ink cartridge temperature control method according to an embodiment of this application is applied to an ink cartridge device. The ink cartridge device includes an ink chamber, at least one heating chamber, a first temperature sensor disposed in the ink chamber, a second temperature sensor disposed in the heating chamber, a heating rod disposed in the heating chamber, and a controller electrically connected to the first temperature sensor, the second temperature sensor, and the heating rod. The heating chamber is filled with a heat-conducting liquid, the heating rod is immersed in the heat-conducting liquid, the heating chamber is connected to the ink chamber, and heat exchange can occur between the heating chamber and the ink chamber.

[0007] The ink cartridge temperature control method according to embodiments of this application includes: The ink temperature value detected by the first temperature sensor, the heat transfer fluid temperature value detected by the second temperature sensor, and the printing press operating status signal are acquired in real time. The temperature values ​​of the heat transfer fluid and the ink are used to determine the safety interlock. If the safety interlock fails, the heating rod is turned off. If the temperature value of the heat transfer fluid exceeds a preset heat transfer fluid temperature threshold or the temperature value of the ink exceeds a preset ink temperature threshold, the safety interlock fails. If the safety interlock is triggered, the corresponding preset target temperature range is selected based on the working status signal; The heating rod is controlled to start and stop based on the ink temperature value and the target temperature range.

[0008] The ink cartridge temperature control method according to the embodiments of this application has at least the following beneficial effects: The ink cartridge temperature control method acquires the ink temperature value detected by the first temperature sensor and the heat transfer fluid temperature value detected by the second temperature sensor in real time, and introduces a highest-priority safety interlock judgment mechanism, breaking the limitation of controlling only the ink temperature. In the control logic, the system uses both the heat transfer fluid temperature and the ink temperature as safety assessment standards. Once the heat transfer fluid temperature value exceeds a preset heat transfer fluid temperature threshold or the ink temperature value exceeds a preset ink temperature threshold, the system determines that the safety interlock has failed and immediately forces the heating rod to shut down. This effectively prevents potential hazards such as vaporization and boiling, seal damage, or ink thermal degeneration caused by local overheating of the heat transfer medium, improving the safety of the ink cartridge device operation and the reliability of the equipment. The ink cartridge temperature control method acquires the printing press's operating status signal in real time, and, under the premise that the safety interlock has passed, dynamically selects the corresponding preset target temperature range according to the actual operating status of the printing press, thereby controlling the start and stop of the heating rod. This control strategy addresses the technical pain point of existing ink cartridge heating devices being disconnected from the operating conditions of the printing press, enabling the ink cartridge temperature control to adapt to the printing press's operational needs in real time, reducing overall energy consumption, and providing the most suitable ink temperature under different operating conditions, thereby ensuring the stability of ink viscosity.

[0009] According to some embodiments of this application, the ink cartridge device further includes a liquid level sensor disposed in the ink chamber, the liquid level sensor detecting the liquid level value of the ink chamber in real time; If the liquid level is lower than a preset liquid level threshold, the safety interlock will also fail.

[0010] According to some embodiments of this application, selecting the corresponding target temperature range based on the operating status signal includes: If the operating status signal indicates a sleep state, then the heating rod is turned off; If the working status signal indicates standby mode, then the target temperature range is set to the preset heat preservation mode temperature range. If the working status signal indicates a cleaning state, then the target temperature range is set to the preset cleaning mode temperature range. If the working status signal indicates high-speed printing, then the target temperature range is set to the preset normal printing mode temperature range. The set value of the temperature range for the heat preservation mode is lower than the set value of the temperature range for the normal printing mode, and the set value of the temperature range for the cleaning mode is higher than the set value of the temperature range for the normal printing mode.

[0011] According to some embodiments of this application, controlling the start and stop of the heating rod based on the ink temperature value and the target temperature range includes: If the ink temperature is lower than the lower limit of the target temperature range, then the heating rod is activated; If the ink temperature value is higher than the upper limit of the target temperature range, then the heating rod is turned off.

[0012] According to some embodiments of this application, it further includes: monitoring the thermal resistance of the ink cartridge device; if the ink cartridge device does not meet the preset thermal resistance condition, issuing a heat transfer fluid maintenance warning.

[0013] According to some embodiments of this application, the step of monitoring the thermal resistance of the ink cartridge device, and issuing a heat transfer fluid maintenance warning if the ink cartridge device does not meet a preset thermal resistance condition, includes: The surface temperature of the heating rod, the temperature value of the ink, and the real-time power of the heating rod are obtained according to a preset time interval. The thermal resistance value is calculated based on the surface temperature of the heating rod, the ink temperature, and the real-time power. ,in, R The thermal resistance value is... T heat The surface temperature of the heating rod. Tink The ink temperature value. P The real-time power; Determine whether the thermal resistance value exceeds a preset thermal resistance threshold. If it does, issue a maintenance warning for the heat transfer fluid.

[0014] According to some embodiments of this application, the heating rod is a PTC heater; the surface temperature of the heating rod is obtained by calculating the real-time resistance by real-time acquisition of the voltage and current at both ends of the PTC heater, and based on the preset resistance-temperature characteristic curve of the PTC heater.

[0015] According to some embodiments of this application, controlling the start and stop of the heating rod based on the ink temperature value and the target temperature range includes: Based on a preset bidirectional thermal accumulation model, the ink outlet temperature at the bottom of the ink chamber is estimated according to the ink temperature value. If the ink outlet temperature is lower than the lower limit of the target temperature range, then the heating rod is activated; If the ink outlet temperature is higher than the upper limit of the target temperature range, then the heating rod is turned off.

[0016] According to some embodiments of this application, the bidirectional thermal accumulation model is as follows: out ink in out

[0017] Wherein, the integration interval is history, t out The ink outlet temperature value. ink The ink temperature value. in This is the driving term for the net heat inflow from the heating chamber to the ink chamber. out This is a drive term for the net heat outflow from the ink chamber to the heating chamber. γ The heat inflow coefficient, η This is the heat outflow coefficient.

[0018] According to some embodiments of this application, the number of heating chambers is two, and the two heating chambers are respectively disposed on opposite sides of the ink chamber; The net heat outflow driving term from the ink chamber to the heating chamber is: in ) max right

[0019] The net heat outflow driving term from the ink chamber to the heating chamber is: out left right

[0020] Among them, the The temperature of the heat-conducting fluid in one of the two heating chambers. The temperature of the heat transfer fluid in the other of the two heating chambers. Attached Figure Description

[0021] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of the ink cartridge device in the embodiment; Figure 2 This is an exploded structural diagram of the ink cartridge device in the embodiment from another perspective. Figure 3 This is a schematic diagram of the main process of the ink cartridge temperature control method in the embodiment; Figure 4 This is a schematic diagram of the thermal resistance detection process in an example.

[0022] Figure label: Ink chamber 100; ink inlet 110; liquid level sensor 120; solenoid valve 130; first temperature sensor 140; heating chamber 200; heating rod 210; liquid inlet 220; second temperature sensor 230. Detailed Implementation

[0023] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0024] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0025] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0026] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0027] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0028] It should be noted that in all specific embodiments of this application, when processing data related to user identity or characteristics, such as user information, user behavior data, user historical data, and user location information, user permission or consent is obtained first. Furthermore, the collection, use, and processing of this data comply with relevant laws, regulations, and standards. In addition, when embodiments of this application require access to sensitive personal information of users, separate permission or consent from the user is obtained through pop-ups or redirection to confirmation pages. Only after obtaining the user's separate permission or consent is the necessary user-related data required for the proper functioning of these embodiments acquired.

[0029] An example of an ink cartridge temperature control method is applied to an ink cartridge device. For instance... Figure 1 and Figure 2As shown, the ink cartridge device of this embodiment includes an ink chamber 100, at least one heating chamber 200, a first temperature sensor 140 disposed in the ink chamber, a second temperature sensor 230 disposed in the heating chamber, a heating rod 210 disposed in the heating chamber, and a controller electrically connected to the aforementioned sensors and the heating rod 210. The heating chamber is filled with a heat-conducting liquid, and the heating rod is immersed in the heat-conducting liquid. The heating chamber 200 and the ink chamber 100 are connected by a heat-conducting partition, allowing heat exchange between the heating chamber and the ink chamber.

[0030] For example, the interior of the ink cartridge housing is divided into an ink chamber 199 and two heating chambers 200 located on opposite sides of it by a thermally conductive partition. The two heating chambers are symmetrically arranged on both sides of the ink chamber. The thermally conductive partition can be made of a high thermal conductivity metal material (such as aluminum alloy) to ensure the transfer of heat from the heating chamber to the ink chamber. Each heating chamber can be equipped with one or more heating rods, which are directly immersed in a thermally conductive liquid. The heat is evenly transferred to the thermally conductive partition through the thermally conductive liquid, and then conducted to the ink in the ink chamber by the thermally conductive partition. The thermally conductive liquid can be a liquid with good thermal conductivity and chemical stability, such as deionized water, antifreeze thermally conductive fluid, or silicone oil.

[0031] like Figure 1 As shown, the ink cartridge temperature control method in this embodiment includes, but is not limited to, steps S100 to S400: S100: Real-time acquisition of ink temperature value detected by the first temperature sensor, heat transfer fluid temperature value detected by the second temperature sensor, and printing press operating status signal; S200: Perform a safety interlock judgment on the temperature values ​​of the heat transfer fluid and the ink. If the safety interlock fails, turn off the heating rod. Specifically, if the temperature value of the heat transfer fluid exceeds the preset temperature threshold of the heat transfer fluid or the temperature value of the ink exceeds the preset temperature threshold of the ink, the safety interlock fails. S300: When the safety interlock is activated, select the corresponding preset target temperature range based on the working status signal; S400: Controls the heating rod to start and stop based on the ink temperature value and the target temperature range.

[0032] In step S100, the controller cyclically reads the detection data from each sensor at a preset sampling period (e.g., once every 0.5 to 2 seconds). The first temperature sensor is located inside the ink chamber, with its temperature probe immersed in the ink, used to detect the current temperature of the ink in real time. The second temperature sensor is located inside the heating chamber, used to detect the current temperature of the heat-conducting liquid in the heating chamber in real time. In this embodiment, both the first and second temperature sensors can be common temperature sensing elements such as PT100 resistance temperature detectors (RTDs), NTC thermistors, or thermocouples. When the ink cartridge device includes two heating chambers, each heating chamber is equipped with a second temperature sensor, and the controller can obtain the temperature value of the heat-conducting liquid in each heating chamber.

[0033] The printing press's operating status signals are obtained by the controller from the printing press's main control system via a communication interface. This communication interface can be a wired interface (such as RS485, CAN bus, Ethernet interface, etc.) or a wireless communication module (such as Wi-Fi, Bluetooth, etc.). The printing press's operating status signals must include at least a status indicator that characterizes the printing press's current operating condition, such as standby, printing, cleaning, or sleep mode. The controller identifies the printing press's current operating condition based on this status signal to select a matching temperature control strategy in subsequent steps.

[0034] Understandably, the controller can also connect to a host computer via a communication interface to upload real-time data (including ink temperature, heat transfer fluid temperature, heating rod operating status, etc.) and alarm information, and receive control parameters (such as target temperature ranges and safety thresholds for each operating condition) from the host computer. This allows operators to remotely monitor and configure parameters for one or more ink cartridge devices via a host computer, which is particularly suitable for centralized management scenarios of multi-color ink cartridges such as CMYK.

[0035] In step S200, the safety interlock determination is the highest priority step in the entire control method. Its purpose is to ensure that the ink cartridge device will not cause safety risks due to abnormal temperature under any circumstances. The determination criteria for the safety interlock can be set according to the received device parameters to adapt to different specifications of ink cartridge devices and different types of thermally conductive liquids. In some embodiments, the determination logic for the safety interlock includes: if the temperature value of the thermally conductive liquid exceeds a preset thermally conductive liquid temperature threshold, or the ink temperature value exceeds a preset ink temperature threshold, then the safety interlock is determined to fail. When the safety interlock fails, the controller immediately outputs a stop signal to shut down all heating rods to prevent the thermally conductive liquid from overheating and vaporizing or the ink from denaturing due to overheating.

[0036] Understandably, the temperature threshold of a heat transfer fluid should be set below its boiling point, with sufficient safety margin. For example, when the heat transfer fluid is deionized water, the temperature threshold can be set to a value between 60°C and 80°C; when the heat transfer fluid is silicone oil, the threshold can be appropriately increased based on the temperature resistance characteristics of the silicone oil. The temperature threshold of an ink should be determined based on the ink's heat resistance characteristics to avoid chemical denaturation or changes in physical properties due to overheating; for example, it can be set to a value between 45°C and 60°C.

[0037] As the highest priority criterion, the safety interlock means that regardless of the printing press's operating state or whether the ink temperature is within the target range, the controller should immediately shut down the heating element if either the heat transfer fluid temperature or the ink temperature exceeds its corresponding safety threshold. Only if the safety interlock is successful (i.e., both the heat transfer fluid temperature and the ink temperature do not exceed their respective safety thresholds) will the controller continue with subsequent temperature control steps.

[0038] Understandably, when the safety interlock is triggered, the controller can also perform the following operations simultaneously: issue an audible and visual alarm to alert on-site operators; and upload alarm information to the host computer via the communication interface, including the alarm type (heat transfer fluid overheating or ink overheating), the temperature value at the time of triggering, and the timestamp, for recording and traceability.

[0039] It should be noted that the judgment criteria for safety interlocks are not limited to the aforementioned heat transfer fluid temperature threshold and ink temperature threshold. In other embodiments, liquid level detection, temperature change rate monitoring, etc., can also be incorporated into the judgment system of safety interlocks to construct a more comprehensive multi-level safety protection mechanism, which will be further explained in subsequent embodiments.

[0040] In step S300, after the safety interlock is verified, the controller selects a set of preset target temperature ranges that matches the current operating condition based on the printer operating status signal obtained in step S100. Different operating states correspond to different temperature control requirements. By dynamically adjusting the target temperature range, energy consumption optimization can be achieved while ensuring print quality.

[0041] The target temperature range is typically defined as a lower temperature limit T_min and an upper temperature limit T_max, i.e., [T_min, T_max]. The controller internally stores target temperature ranges corresponding to each operating state. For example, in a typical application scenario: when the printer is in normal printing mode, the ink needs to be maintained within the optimal printing temperature range to ensure moderate ink viscosity and good inkjet consistency. In this case, the target temperature range is set to the normal printing mode temperature range, such as [30℃, 35℃]. When the printer is in standby mode (such as a short pause during paper changes), it is not necessary to maintain the ink at the optimal printing temperature, but it is necessary to prevent the ink from increasing in viscosity or even solidifying due to excessively low temperature. In this case, the target temperature range can be appropriately lowered to maintain the temperature with lower power, thereby reducing unnecessary energy consumption. When the printer is in cleaning mode, a higher ink temperature helps reduce ink viscosity and improve cleaning effectiveness. In this case, the target temperature range can be appropriately increased to enhance cleaning efficiency. When the printer is in sleep mode (such as when it is not working for a long time at night), the heating element can be turned off to achieve deep energy savings.

[0042] The specific values ​​of the target temperature ranges for each of the above operating conditions can be adjusted according to the actual ink type, ambient temperature, and equipment specifications. Different ink compositions have different optimal printing temperatures; for example, the optimal printing temperature for water-based inks is typically 25°C to 30°C, while the optimal printing temperature for UV inks is typically 35°C to 45°C. Operators can set or modify the target temperature range for each operating condition via a host computer or the controller's local interface to flexibly adapt to various ink types.

[0043] In step S400, after determining the target temperature range [T_min, T_max] corresponding to the current operating condition, the controller compares the ink temperature value obtained in step S100 with the target temperature range, and controls the heating rod to start or stop accordingly, so that the ink temperature is maintained within the target range.

[0044] For example, in a basic implementation, the controller uses a threshold comparison method: when the ink temperature is below the lower limit T_min of the target temperature range, the heating element is activated; when the ink temperature is above the upper limit T_max of the target temperature range, the heating element is deactivated; and when the ink temperature is between T_min and T_max, the current state of the heating element remains unchanged. This control method is simple in structure, highly reliable, and suitable for applications where high temperature accuracy is not required.

[0045] For example, in another implementation, the controller can determine the control basis based on a more refined temperature estimation model. For instance, the controller can estimate the temperature at the ink outlet at the bottom of the ink chamber using a heat accumulation model based on the ink temperature and the temperature of the heat transfer fluid in the heating chamber, and then compare this estimated temperature with the target temperature range. This approach can more accurately reflect the actual ink supply temperature, improve the consistency of inkjet quality, and is suitable for applications requiring high temperature accuracy.

[0046] Regarding the control method of the heating rod, the controller can adopt on / off control (i.e., full power start-up or complete shutdown) or pulse width modulation (PWM) control. When using PWM control, the controller adjusts the heating power by adjusting the duty cycle of the heating rod, which can achieve a smoother temperature adjustment effect and reduce the temperature fluctuation amplitude.

[0047] Steps S100 to S400 in the above embodiment constitute a complete control cycle. The controller repeatedly executes the above steps at a preset control frequency (e.g., once per second) to achieve continuous closed-loop control of the ink temperature. In each control cycle, the safety interlock judgment is always executed with the highest priority to ensure equipment safety; the temperature range selection for operating condition linkage allows the control strategy to dynamically adapt to the actual operating needs of the printing press; and the start / stop control of the heating rod ensures that the ink temperature is always maintained within the target range required by the current operating condition.

[0048] The ink cartridge temperature control method described in this embodiment sets the safety interlock judgment to the highest priority, ensuring that heating can be immediately cut off when the temperature of the heat transfer fluid or ink is abnormal, effectively preventing safety risks such as overheating and vaporization of the heat transfer fluid or denaturation of the ink; by dynamically selecting the target temperature range based on the printer's operating status signal, it realizes the linkage control between ink cartridge heating and printer operating conditions, reducing energy consumption while ensuring print quality; by comparing the ink temperature value with the target temperature range to control the start and stop of the heating rod, it achieves closed-loop constant temperature control of the ink temperature.

[0049] In some embodiments, a safety interlock mechanism based on liquid level detection is also provided.

[0050] Understandably, in practical applications, when the ink level in the ink chamber is too low, the coverage area of ​​the ink on the heat-conducting baffle decreases, and the upper part of the baffle is exposed to the air. Heat cannot be effectively transferred to the ink, which may lead to an abnormal increase in the temperature of the heat-conducting fluid, or even cause the heating rod to burn out. Therefore, liquid level monitoring is an indispensable part of the safety interlock system.

[0051] In this embodiment, the ink cartridge device also includes a liquid level sensor disposed within the ink chamber. The liquid level sensor is electrically connected to the controller and is used to detect the ink level value L within the ink chamber in real time. The liquid level sensor can be any one of a float switch, an ultrasonic liquid level sensor, a capacitive liquid level sensor, or a photoelectric liquid level sensor.

[0052] For example, a float switch has a simple structure and low cost, making it suitable for scenarios where only a determination of whether the liquid level is below a certain fixed threshold is needed. Its output is a switching signal (high or low level). Ultrasonic and capacitive liquid level sensors can output continuous liquid level values, making them suitable for scenarios requiring precise monitoring of liquid level changes. In this embodiment, a float switch can be used, installed on the inner wall of the ink chamber, with its actuation position corresponding to a preset liquid level threshold L_min.

[0053] The liquid level threshold L_min can be set in the following principle: ensure that when the liquid level is at L_min, the ink can still completely cover the heat exchange surface where the heat-conducting partition contacts the ink chamber, guaranteeing effective heat transfer to the ink. Specifically, L_min should not be lower than the height of the upper edge of the effective heat exchange surface of the heat-conducting partition on the ink chamber side. For example, for an ink cartridge with an effective heat exchange surface height of 80mm, L_min can be set to the position corresponding to a liquid level height of 85mm, leaving a safety margin of 5mm.

[0054] In the safety interlock judgment of step S200, the liquid level interlock and the temperature interlock together constitute a multi-level safety protection system, and its judgment logic is as follows: The system checks whether the heat transfer fluid temperature value T_oil exceeds the preset heat transfer fluid temperature threshold T_safe_oil. If it does, the safety interlock fails, the heating rod is immediately shut off, and a heat transfer fluid overheating alarm signal is issued. Heat transfer fluid overheating is a highest priority safety event and should be addressed immediately regardless of the fluid level or ink temperature.

[0055] Determine the ink temperature value T ink Check if the preset ink temperature threshold T_safe_ink is exceeded. If it is exceeded, the safety interlock fails, the heating rod is turned off, and an ink over-temperature alarm signal is issued.

[0056] Determine whether the liquid level L is lower than the preset liquid level threshold L_min. If it is lower than L_min, the safety interlock fails, the heating rod is turned off (or the heating rod is prevented from starting), and a low liquid level alarm signal is issued.

[0057] Understandably, there is no restriction on the priority order of the above three interlocking conditions; if any one of them is met, the safety interlock will not be passed.

[0058] The controller connects to the printing press's main control system via a communication interface to receive real-time operating status signals from the printing press. These signals can be status codes actively pushed by the main control system or status flags that the controller periodically queries and retrieves.

[0059] In some embodiments, the working status signal includes at least the following four states: hibernation state, standby state, cleaning state, and high-speed printing state.

[0060] When the printing press is in sleep mode, it indicates that the press has not been used for an extended period, such as during a nighttime shutdown or when there are no printing tasks for a long time. In this state, the controller shuts off the heating element, stopping heating and only maintaining low-power operation for sensor data acquisition and communication. This strategy aims to minimize energy consumption and avoid unnecessary heating. When the printing press switches from sleep mode to another operating state, the controller reselects the corresponding target temperature range based on the new operating state and activates the heating element for preheating.

[0061] When the printer is in standby mode, it indicates a short-term pause in printing, such as during paper changes, while waiting for a print job, or when the operator temporarily leaves. In this state, the controller sets the target temperature range to the preset standby mode temperature range [T_min_standby, T_max_standby]. The standby mode temperature range is set lower than the normal printing mode temperature range. This is to maintain the basic fluidity of the ink at a lower temperature, preventing the ink from visibly increasing in viscosity or even solidifying due to excessively low temperatures, while simultaneously reducing heating power to save energy. Since the printhead does not perform ink ejection in standby mode, the ink does not need to reach the optimal printing temperature; therefore, appropriately lowering the temperature setting is reasonable and beneficial.

[0062] When the printing press is in cleaning mode, it indicates that the press is performing a printhead cleaning program. The purpose of printhead cleaning is to unclog clogged nozzles and remove deposited ink residue. During the cleaning process, higher ink temperatures result in lower viscosity, better flowability, and better cleaning effectiveness. Therefore, the controller sets the target temperature range to the preset cleaning mode temperature range [T_min_clean, T_max_clean]. The set values ​​for the cleaning mode temperature range are higher than those for the normal printing mode. By temporarily increasing the ink temperature and reducing ink viscosity, the ink flows more easily through the fine channels of the nozzles, thereby improving cleaning efficiency and reducing the amount of ink and time required for cleaning.

[0063] When the printing press is in high-speed printing mode, it indicates that the press is performing a continuous printing task. At this time, the printhead ejects ink droplets at a high frequency, placing the highest demands on ink temperature stability and ink supply smoothness. The controller sets the target temperature range to the preset normal printing mode temperature range [T_min_normal, T_max_normal]. The set value of the normal printing mode temperature range is determined based on the optimal printing temperature of the ink used. Different types of ink have different optimal printing temperatures; for example, water-based inks are typically 25-30℃, and UV inks are typically 35-45℃. Operators can set the corresponding temperature parameters according to the actual ink type used via the host computer or the controller's local interface.

[0064] In some embodiments, the target temperature ranges corresponding to the four operating conditions satisfy the following relationship: temperature range of heat preservation mode < temperature range of normal printing mode < temperature range of cleaning mode. This temperature gradient design ensures that the ink temperature meets functional requirements while optimizing energy consumption under different operating conditions.

[0065] It should be noted that the above four operating states are not exhaustive. In other implementations, more state types and corresponding temperature modes can be added according to the actual operating conditions of the printing press. For example, a "low-speed printing state" can be added, with its temperature setting between standby mode and normal printing mode; or a "preheating state" can be added, which heats the ink to the target temperature quickly with higher power after the printing press wakes up from hibernation and before the actual printing.

[0066] In some embodiments, a threshold comparison control strategy is employed, that is, the ink temperature value... T ink The heating rod is directly compared with the lower limit T_min and upper limit T_max of the target temperature range, and the start and stop of the heating rod are determined based on the comparison result.

[0067] For example, the specific control logic is as follows: When the ink temperature value T ink When the temperature is below the lower limit T_min of the target temperature range, it indicates that the ink temperature is too low and heating is required. The controller outputs a heating start signal to drive the heating rod to start working, inputting heat into the heat-conducting liquid. The heat is transferred to the ink chamber through the heat-conducting liquid and the heat-conducting partition, causing the ink temperature to gradually rise.

[0068] When the ink temperature value T ink When the ink temperature exceeds the upper limit T_max of the target temperature range, it indicates that the ink temperature has reached or exceeded the target upper limit, and further heating is unnecessary. The controller outputs a heating stop signal to turn off the heating element. Afterward, the ink temperature gradually decreases due to natural heat dissipation or the addition of new ink.

[0069] When the ink temperature value T ink It lies between T_min and T_max (i.e., T_min ≤ T ink When T ≤ T_max), the heating rod maintains its current state. That is, if the heating rod is currently on, it continues to heat; if the heating rod is currently off, it remains off.

[0070] Understandably, the control logic described above is essentially a switching control strategy with hysteresis. The lower limit of the target temperature range, T_min, serves as the heating start threshold, and the upper limit, T_max, serves as the heating stop threshold. The difference between the two, ΔT_band = T_max - T_min, constitutes the hysteresis band of the temperature control.

[0071] The setting of a hysteresis band is of significant engineering importance: without a hysteresis band (i.e., T_min = T_max), the heating element will frequently start and stop near the temperature critical point, which not only increases the mechanical wear of relays or switching devices and shortens their service life, but may also lead to electromagnetic interference and power fluctuations. Properly setting the hysteresis band can effectively avoid frequent switching of the heating element, allowing the temperature to fluctuate smoothly within an acceptable range, balancing temperature control accuracy and equipment reliability.

[0072] Understandably, during the long-term operation of the ink cartridge unit, the heat-conducting fluid in the heating chamber will gradually undergo physical or chemical changes due to continuous heating, such as oxidation, impurity precipitation, and mineral salt scaling. These changes will lead to a decrease in the heat transfer performance of the heat-conducting fluid. In addition, the surface of the heat-conducting baffle facing the heating chamber may also accumulate deposits or oxide films due to long-term immersion, further increasing the thermal resistance in the heat transfer path. These changes are usually gradual and will not cause obvious abnormalities in ink or heat-conducting fluid temperature in the early stages. However, as the thermal resistance continues to increase, the heating rod needs to use higher power or take longer to heat the ink to the target temperature, resulting in increased energy consumption. In more serious cases, the surface temperature of the heating rod may rise abnormally, and the heat-conducting fluid temperature sensor may fail to reflect this in time due to its location or response lag, which may eventually lead to safety hazards such as local overheating, boiling, or even damage to the seals of the heat-conducting fluid.

[0073] Therefore, in some embodiments, in addition to the temperature control main process in steps S100 to S400, step S500 is also included: monitoring the thermal resistance of the ink cartridge device, and issuing a heat transfer fluid maintenance warning if the ink cartridge device does not meet the preset thermal resistance conditions.

[0074] In step S500, while executing the main temperature control process, the controller periodically performs thermal resistance monitoring tasks at preset time intervals. This time interval can be set according to actual needs, for example, every 30 seconds to 5 minutes. In some embodiments, the execution frequency of thermal resistance monitoring can also be dynamically adjusted according to the working state of the heating rod. For example, the monitoring frequency can be appropriately increased during continuous operation of the heating rod, and decreased or paused during operation when the heating rod is off, to save computing resources.

[0075] During each thermal resistance monitoring cycle, the controller acquires the surface temperature of the heating rod, the ink temperature, and the real-time power of the heating rod, and calculates the thermal resistance value, which characterizes the heat transfer efficiency, based on these parameters. The controller then compares the calculated thermal resistance value with preset thermal resistance conditions to determine whether the current heat transfer performance of the heat transfer fluid is still within an acceptable range. If the thermal resistance value does not meet the preset thermal resistance conditions (e.g., exceeds a preset thermal resistance threshold), the controller determines that the heat transfer efficiency of the heat transfer fluid has significantly decreased and issues a heat transfer fluid maintenance warning signal.

[0076] Thermal resistance conditions may include, but are not limited to, one or more of the following criteria: The single thermal resistance value exceeds the preset thermal resistance threshold R_max; The thermal resistance value exceeds the preset thermal resistance threshold R_max multiple times in a row to avoid false alarms caused by transient fluctuations; If the rate of increase of thermal resistance exceeds the preset rate threshold, that is, if the thermal resistance increases rapidly in a short period of time, it indicates that the heat transfer fluid is deteriorating at an accelerated rate.

[0077] The thermal resistance threshold R_max can be set as follows: After the ink cartridge device is first used or the heat transfer fluid is replaced, the controller continuously collects thermal resistance data during the initial stage of normal device operation (e.g., the first 24 hours), calculates its average value as the initial thermal resistance value R_initial, and stores R_initial in the controller's non-volatile memory; R_max is set to a preset multiple of R_initial, for example, 1.3 to 2.0 times, preferably 1.5 times. Using a multiple setting method relative to the initial value can automatically adapt to differences in thermal resistance references under conditions such as different ink cartridge specifications, different heat transfer fluid types, and different heating rod power, eliminating the need for manual calibration.

[0078] The output methods for heat transfer fluid maintenance early warning signals may include: driving a local alarm (such as a buzzer or indicator light) to issue an audible and visual alarm via the controller; uploading the early warning information to the host computer via the communication interface, where the host computer will pop up a maintenance prompt window on the monitoring interface and record the event log; or forwarding the information to the operation and maintenance management system via the host computer to generate a maintenance work order.

[0079] After the operator completes the heat transfer fluid replacement or heating chamber cleaning maintenance according to the warning prompts, the warning status can be cleared by issuing a reset command from the host computer or by using the local reset button on the cartridge device. After resetting, the controller re-enters the initial thermal resistance measurement stage, collects the new R_initial and updates R_max to adapt to the post-maintenance equipment state.

[0080] It should be noted that the thermal resistance monitoring process in step S500 and the main temperature control process in steps S100 to S400 run independently and in parallel. The main temperature control process runs at a higher execution frequency (e.g., every second or every few hundred milliseconds) to ensure real-time responsiveness of temperature control and safety interlocks; the thermal resistance monitoring process runs at a lower frequency to avoid consuming excessive controller computing resources. The two processes exchange information through shared sensor data, but their control logic does not interfere with each other. When the thermal resistance monitoring issues a maintenance warning, the main temperature control process continues to operate normally to ensure that ink temperature control is not affected; however, operators should schedule maintenance within a reasonable time to prevent further deterioration of thermal resistance, which could lead to frequent triggering of safety interlocks.

[0081] Understandable, such as Figure 4 As shown, in some embodiments, step S500 may further include, but is not limited to, steps S510 to S530: S510: Obtain the surface temperature of the heating rod, the ink temperature value, and the real-time power of the heating rod according to a preset time interval; S520. Calculate the thermal resistance value based on the heating rod surface temperature, ink temperature, and real-time power. The thermal resistance value is... Where R is the thermal resistance value. T heat The surface temperature of the heating rod. T ink Here, P represents the ink temperature value, and P represents the real-time power. S530: Determine whether the thermal resistance value exceeds the preset thermal resistance threshold. If it does, issue a maintenance warning for the heat transfer fluid.

[0082] In step S510, the ink temperature value T ink The temperature data is obtained in real time by a first temperature sensor located inside the ink chamber, and is the same as the temperature data used in the main temperature control process, eliminating the need for additional sensors. The real-time power of the heating rod... P The controller collects the voltage U across the heating rod and the current I flowing through it in real time, according to... P = U × I The calculation is as follows. In some implementations, if the heating rod is driven using pulse width modulation (PWM), the real-time power is... P The average power of the heating rod at the current duty cycle is, i.e.P = U × I ×D, where D is the current PWM duty cycle.

[0083] It should be noted that thermal resistance calculations should be performed when the heating rod is in a stable operating state to ensure the accuracy of the results. Specifically, before performing the thermal resistance calculation, the controller determines whether the heating rod has been operating continuously for more than a preset stabilization time (e.g., 30 to 120 seconds). If the heating rod has just started or is in a turned-off state, the thermal resistance calculation is skipped, and the system waits for the next monitoring cycle. This is because in the initial stage of heating rod startup, the surface temperature of the heating rod, the temperature of the heat transfer fluid, and the ink temperature are all in a rapidly changing transient process. At this time, the calculated thermal resistance value fluctuates greatly and cannot accurately reflect the steady-state heat transfer performance of the heat transfer fluid.

[0084] In step S520, the thermal resistance value is calculated based on the surface temperature of the heating rod, the ink temperature, and the real-time power. The thermal resistance value is... ,in, R This is the thermal resistance value. T heat The surface temperature of the heating rod. T ink This is the ink temperature value. P This represents real-time power. The physical meaning of this formula is: thermal resistance. R This characterizes the total thermal resistance along the entire heat transfer path from the heating rod surface to the ink, including the convective heat transfer resistance between the heating rod surface and the heat transfer fluid, the internal thermal conductivity resistance of the heat transfer fluid, the contact thermal resistance between the heat transfer fluid and the heat transfer partition, the thermal conductivity resistance of the heat transfer partition itself, and the convective heat transfer resistance between the heat transfer partition and the ink. When the heat transfer fluid is fresh and the surface of the heat transfer partition is clean, the thermal resistance of each of the above segments is at a low level, and the total thermal resistance R is small. As the heat transfer fluid ages and deteriorates or scale forms on the surface of the heat transfer partition, the thermal resistance of the relevant segments increases, and the total thermal resistance R increases accordingly.

[0085] To improve the reliability of thermal resistance calculation, in some implementations, the controller can perform a moving average filtering process on the thermal resistance values ​​obtained from multiple consecutive calculations. For example, the arithmetic mean of the most recent 5 to 10 thermal resistance calculations can be taken as the current thermal resistance value to eliminate random errors caused by factors such as sensor noise and power fluctuations in a single measurement.

[0086] In step S530, the thermal resistance value calculated in step S520 is... R (Or the filtered thermal resistance value) is compared with the preset thermal resistance threshold R_max. If R If R_max is exceeded, it is determined that the heat transfer efficiency of the heat transfer fluid has dropped to an unacceptable level, and the controller issues a heat transfer fluid maintenance warning.

[0087] In some embodiments, the heating element is a PTC (Positive Temperature Coefficient) heater. A PTC heater is a heating device with a core heating element made of positive temperature coefficient ceramic materials such as barium titanate. Its resistance increases significantly with increasing temperature, exhibiting self-limiting temperature characteristics. When the temperature of the PTC heater approaches its Curie point, the resistance increases sharply, the current flowing through it decreases significantly, and the heating power automatically decreases, thus physically preventing the heater surface temperature from rising indefinitely. This characteristic provides an inherent safety guarantee for the cartridge device.

[0088] The resistance-temperature relationship of PTC heaters follows a clear correspondence: given PTC material and structural parameters, each resistance value uniquely corresponds to a temperature value. PTC heater manufacturers typically provide resistance-temperature characteristic curves (RT curves) or resistance-temperature comparison tables (RT comparison tables) for their heater models. These curves or tables record the resistance values ​​of the PTC element at different temperatures.

[0089] Based on the above characteristics, in some embodiments the surface temperature of the heating rod is estimated in the following way. T heat : (1) The controller acquires the voltage U across the PTC heating rod and the current I flowing through the PTC heating rod in real time through the built-in voltage acquisition circuit and current acquisition circuit. Voltage acquisition can be performed by using a resistor divider network to proportionally reduce the high voltage across the heating rod to the input range of the controller's analog-to-digital converter (ADC); current acquisition can be performed by connecting a small-value precision sampling resistor (e.g., 0.1Ω, accuracy 0.1%) in series in the heating rod power supply circuit, measuring the voltage across the sampling resistor and converting it into a current value, or by using a Hall current sensor for non-contact current measurement.

[0090] (2) Based on the collected voltage U and current I, calculate the real-time resistance value R_ptc = U / I of the PTC heating rod according to Ohm's law.

[0091] (3) The calculated R_ptc is compared with the PTC heater resistance-temperature lookup table pre-stored in the controller. This lookup table is provided by the PTC heater manufacturer and written into the controller's non-volatile memory before the cartridge device leaves the factory. If R_ptc is exactly equal to the resistance value corresponding to a certain temperature point in the lookup table, then that temperature value is directly read as the resistance value. T heat If R_ptc falls between two adjacent temperature points in the lookup table, then linear interpolation is used for calculation. T heat .

[0092] It should be noted that the value was estimated using the PTC resistance-temperature characteristic curve. T heat The temperature of the PTC heating element itself may deviate from the actual temperature of the heating rod's outer surface. This deviation mainly depends on the internal thermal resistance between the PTC element and the heating rod's outer shell, as well as the current heat dissipation conditions. In engineering practice, this deviation is typically within the range of 2°C to 5°C, which is acceptable for trend analysis of thermal resistance monitoring, as thermal resistance monitoring focuses on the relative change trend of the thermal resistance value over time, rather than absolute accuracy.

[0093] In other implementations, if for T heat For applications requiring higher measurement accuracy, a third temperature sensor (such as a patch thermocouple or thin-film platinum resistance thermometer) can be added to the outer surface of the heating rod to directly measure the outer surface temperature of the heating rod. T heat This method offers higher measurement accuracy but increases the number of sensors and wiring complexity. In practical applications, one of the two methods can be chosen based on cost and accuracy requirements.

[0094] Understandably, the first temperature sensor is typically installed in the middle region of the ink chamber, and it detects the temperature value. T ink This reflects the temperature state in the middle of the ink chamber. The ink outlet at the bottom of the ink chamber is where the ink actually flows out and supplies the printhead. Due to spatial differences in heat distribution during the transfer of heat from the heating chambers on both sides through the heat-conducting partition to the ink chamber, coupled with the convection and thermal conductivity characteristics of the ink itself, the actual temperature at the ink outlet often deviates from the temperature in the middle of the ink chamber. When the heating rod is first activated, heat is first transferred to the upper part of the ink chamber, at which point the temperature at the ink outlet may still be below the target range; however, when the heating rod is turned off, due to the inertial accumulation effect of heat, the temperature at the ink outlet may continue to rise for a period of time. This uneven temperature distribution and thermal inertia effect mean that relying solely on... T ink When controlling the ink output, the actual temperature at the ink outlet may deviate from the target range, thus affecting the consistency and stability of inkjet printing.

[0095] In some embodiments, the controller does not directly use the ink temperature value detected by the first temperature sensor. T ink Instead of serving as a control criterion, it is based on a preset two-way thermal accumulation model, comprehensively utilizing ink temperature values. T ink In addition to the temperature information of the heating chamber, the temperature value at the ink outlet at the bottom of the ink chamber is estimated. T out and with T outAs a criterion for control.

[0096] The core idea of ​​the two-way heat accumulation model is that the temperature at the ink outlet depends not only on the current ink temperature but also on the cumulative effect of heat exchange between the heating chamber and the ink chamber over a previous period. When the heating chamber temperature is higher than the ink chamber temperature, heat flows from the heating chamber into the ink chamber, and the ink outlet temperature tends to rise; when the ink chamber temperature is higher than the heating chamber temperature (e.g., during the cooling phase after the heating rod is turned off), heat dissipates from the ink chamber, and the ink outlet temperature tends to decrease. This model distinguishes between heat inflow and heat outflow and considers the time decay characteristics of heat transfer, thus reflecting the actual temperature state at the ink outlet more accurately than simply relying on instantaneous temperature values.

[0097] The controller estimates the ink outlet temperature based on a two-way thermal accumulation model. T out Then, the following control logic is executed: like T out If the ink temperature is below the lower limit T_min of the current target temperature range, the heating element will be activated to raise the ink temperature until... T out It has rebounded to the target range; like T out If the temperature exceeds the upper limit T_max of the current target temperature range, the heating rod will be turned off, and heating will stop until... T out It has fallen back to the target range; like T out If the temperature is within the range of [T_min, T_max], the current working state of the heating rod will remain unchanged.

[0098] Direct comparison with the above embodiments T ink Compared with the previous method, the control method of this embodiment has the following advantages: First, the control criteria are closer to actual operating conditions. The ink outlet is a critical location for ink supply to the printhead, and the estimated ink outlet temperature... T out As a control criterion, it can more directly ensure that the ink temperature supplied to the printhead is within the optimal range, thereby improving the consistency of inkjet quality.

[0099] Second, it can compensate for thermal inertia effects. The two-way thermal accumulation model takes into account the cumulative effect of historical heat exchange and the time decay characteristics, and can predict the temperature change trend of the ink nozzle in advance when the heating rod is switched on and off, thereby reducing temperature overshoot or undershoot caused by thermal inertia.

[0100] In some embodiments, the mathematical expression of the two-way thermal accumulation model is: out ink in out

[0101] Wherein, the integration interval is history, t out This refers to the ink outlet temperature value. ink This is the ink temperature value. in This refers to the driving term for the net heat inflow from the heating chamber to the ink chamber. out For the net heat outflow drive from the ink chamber to the heating chamber, γ The heat inflow coefficient, η This is the heat outflow coefficient.

[0102] out for t The estimated ink outlet temperature at any given time; ink The ink temperature value detected by the first temperature sensor at time t is used as the estimated reference temperature.

[0103] in Let τ be the driving term for the net heat inflow from the heating chamber to the ink chamber at time τ. The explanation will be based on an example with two heating chambers (located on the left and right sides of the ink chamber). in ) max right , This refers to the temperature of the heat transfer fluid on the left side of the two heating chambers. This represents the temperature of the heat-conducting fluid on the right side of the two heating chambers. When the average temperature of the heating chamber is higher than the ink temperature... in A positive value indicates that heat is flowing from the heating chamber into the ink chamber; when the average temperature of the heating chamber is lower than or equal to the ink temperature, in The value is zero; out Let τ be the driving term for the net heat outflow from the ink chamber to the heating chamber. This will be explained using an example of two heating chambers (located on the left and right sides of the ink chamber). out left right When the ink temperature is higher than the average temperature of the heating chamber, out A positive value indicates that heat is being dissipated from the ink chamber; when the ink temperature is lower than or equal to the average temperature of the heating chamber, out It is zero.

[0104] The weighting function is exponentially decaying, reflecting the physical law that the influence of historical heat exchange on the current ink outlet temperature gradually weakens as the time interval increases. The closer the heat exchange is to the current moment, the greater its impact on the current ink outlet temperature; the farther the heat exchange is from the current moment, the smaller its impact.

[0105] γ is the heat inflow coefficient, characterizing the efficiency with which heat increases the ink outlet temperature after flowing from the heating chamber into the ink chamber. For example, the value of γ ranges from 0.15 to 0.35. The specific value of γ depends on factors such as the structural dimensions of the ink cartridge, the material and thickness of the thermally conductive partition, and the type of heat-conducting liquid. Generally speaking, the higher the thermal conductivity of the thermally conductive partition, the thinner its thickness, and the larger its heat exchange area, the larger the value of γ.

[0106] η is the heat dissipation coefficient, which characterizes the efficiency of heat loss from the ink chamber to the outside in reducing the ink outlet temperature. The value of η ranges from 0.10 to 0.25. Usually, η is less than γ because the heat loss path includes not only conduction to the heating chamber through the thermally conductive partition, but also heat dissipation to the external environment through the ink cartridge housing, and the latter's heat dissipation efficiency is usually lower than the former's heating efficiency.

[0107] δ is the thermal decay time constant, characterizing the decay rate of the heat accumulation effect, measured in seconds. A larger δ value indicates a longer duration of the historical heat exchange effect. The range of δ is 80 to 180 seconds. The specific value of δ is related to factors such as cartridge volume, ink specific heat capacity, and density. Generally, the larger the cartridge volume and the higher the ink specific heat capacity, the larger the δ value. For small-capacity cartridges (volume less than 500ml), the preferred value for δ is 80 to 100 seconds; for standard-capacity cartridges (volume 500ml to 2L), the preferred value for δ is 100 to 150 seconds, with 120 seconds being a typical preferred value; for large-capacity cartridges (volume greater than 2L), the preferred value for δ is 150 to 180 seconds.

[0108] The integration interval is history, t Δt_history is a preset historical time window, representing the length of time the model traces backward. The selection of Δt_history should be sufficient to cover the main influence range of the heat accumulation effect. Based on the characteristics of the exponential decay function, when Δt_history equals 3 times δ, the decay weight drops to approximately 5%, covering more than 95% of the heat accumulation effect. Therefore, the preferred value for Δt_history is 3δ. When δ is preferably 120 seconds, the preferred value for Δt_history is 360 seconds. In some implementations with limited computational resources, Δt_history can also be 180 seconds (approximately 1.5 times δ), which covers approximately 78% of the heat accumulation effect. The estimation accuracy is slightly reduced, but it still meets the needs of most applications.

[0109] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. A method for controlling ink cartridge temperature, characterized in that, An ink cartridge device is applied to an ink cartridge assembly, the ink cartridge assembly including an ink chamber, at least one heating chamber, a first temperature sensor disposed in the ink chamber, a second temperature sensor disposed in the heating chamber, a heating rod disposed in the heating chamber, and a controller electrically connected to the first temperature sensor, the second temperature sensor, and the heating rod; the heating chamber is filled with a heat-conducting liquid, the heating rod is immersed in the heat-conducting liquid, the heating chamber is connected to the ink chamber, and heat exchange can occur between the heating chamber and the ink chamber; The ink cartridge temperature control method includes: The ink temperature value detected by the first temperature sensor, the heat transfer fluid temperature value detected by the second temperature sensor, and the printing press operating status signal are acquired in real time. The temperature values ​​of the heat transfer fluid and the ink are used to determine the safety interlock. If the safety interlock fails, the heating rod is turned off. If the temperature value of the heat transfer fluid exceeds a preset heat transfer fluid temperature threshold or the temperature value of the ink exceeds a preset ink temperature threshold, the safety interlock fails. If the safety interlock is triggered, the corresponding preset target temperature range is selected based on the working status signal; The heating rod is controlled to start and stop based on the ink temperature value and the target temperature range.

2. The ink cartridge temperature control method according to claim 1, characterized in that, The ink cartridge device also includes a liquid level sensor disposed in the ink chamber, which detects the liquid level value of the ink chamber in real time; If the liquid level is lower than a preset liquid level threshold, the safety interlock will also fail.

3. The ink cartridge temperature control method according to claim 1, characterized in that, The step of selecting the corresponding target temperature range based on the operating status signal includes: If the operating status signal indicates a sleep state, then the heating rod is turned off; If the working status signal indicates standby mode, then the target temperature range is set to the preset heat preservation mode temperature range. If the working status signal indicates a cleaning state, then the target temperature range is set to the preset cleaning mode temperature range. If the working status signal indicates high-speed printing, then the target temperature range is set to the preset normal printing mode temperature range. The set value of the temperature range for the heat preservation mode is lower than the set value of the temperature range for the normal printing mode, and the set value of the temperature range for the cleaning mode is higher than the set value of the temperature range for the normal printing mode.

4. The ink cartridge temperature control method according to claim 1, characterized in that, The step of controlling the heating rod to start and stop based on the ink temperature value and the target temperature range includes: If the ink temperature is lower than the lower limit of the target temperature range, then the heating rod is activated; If the ink temperature value is higher than the upper limit of the target temperature range, then the heating rod is turned off.

5. The ink cartridge temperature control method according to claim 1, characterized in that, Also includes: Thermal resistance monitoring is performed on the ink cartridge device. If the ink cartridge device does not meet the preset thermal resistance conditions, a thermal fluid maintenance warning is issued.

6. The ink cartridge temperature control method according to claim 5, characterized in that, The process of monitoring the thermal resistance of the ink cartridge device, and issuing a heat transfer fluid maintenance warning if the ink cartridge device does not meet the preset thermal resistance condition, includes: The surface temperature of the heating rod, the temperature value of the ink, and the real-time power of the heating rod are obtained according to a preset time interval. The thermal resistance value is calculated based on the surface temperature of the heating rod, the ink temperature, and the real-time power. ,in, R The thermal resistance value is... T heat The surface temperature of the heating rod. T ink The ink temperature value. P The real-time power; Determine whether the thermal resistance value exceeds a preset thermal resistance threshold. If it does, issue a maintenance warning for the heat transfer fluid.

7. The ink cartridge temperature control method according to claim 5, characterized in that, The heating rod is a PTC heater; the surface temperature of the heating rod is obtained by calculating the real-time resistance by real-time acquisition of the voltage and current at both ends of the PTC heater, and based on the preset resistance-temperature characteristic curve of the PTC heater.

8. The ink cartridge temperature control method according to claim 1, characterized in that, The step of controlling the heating rod to start and stop based on the ink temperature value and the target temperature range includes: Based on a preset bidirectional thermal accumulation model, the ink outlet temperature at the bottom of the ink chamber is estimated according to the ink temperature value. If the ink outlet temperature is lower than the lower limit of the target temperature range, then the heating rod is activated; If the ink outlet temperature is higher than the upper limit of the target temperature range, then the heating rod is turned off.

9. The ink cartridge temperature control method according to claim 8, characterized in that, The bidirectional heat accumulation model is as follows: out ink in out Wherein, the integration interval is history, t out The ink outlet temperature value. ink The ink temperature value. in This is a drive term for the net heat inflow from the heating chamber to the ink chamber. out This is a drive term for the net heat outflow from the ink chamber to the heating chamber. γ The heat inflow coefficient, η This is the heat outflow coefficient.

10. The ink cartridge temperature control method according to claim 9, characterized in that, The number of heating chambers is two, and the two heating chambers are respectively arranged on opposite sides of the ink chamber; The net heat outflow driving term from the ink chamber to the heating chamber is: in ) max right The net heat outflow driving term from the ink chamber to the heating chamber is: out left right Among them, the The temperature of the heat-conducting fluid in one of the two heating chambers. The temperature of the heat transfer fluid in the other of the two heating chambers.

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