Non-contact 3D printing hot end heating device and control method

Abstract

The invention discloses a non-contact 3D printing hot end heating device and a control method. Comprising a hot end body arranged at a printing head of the 3D printer, a non-contact heating module set arranged on the peripheral side of the hot end body in a surrounding mode, a PID temperature control system integrated on a control unit of the 3D printer or beside the hot end body, and a temperature sensor arranged on the outer wall of the hot end body in an attached mode. And the heat dissipation structure is assembled on the outer side of the hot end main body and corresponds to the non-heating key area. Through the non-contact heating design, direct contact between a heating element and the hot end body in traditional contact heating is fundamentally avoided, the problems of mechanical abrasion, oxidation and corrosion caused by contact heating are solved, the overall service life of the hot end heating device is remarkably prolonged, the equipment maintenance cost is reduced, and the service life of the hot end heating device is prolonged. And through integrated application of various non-contact heating technologies, the heating uniformity is effectively improved, local overheating or temperature fluctuation is avoided, and the forming precision and quality consistency of printed products are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, specifically to a non-contact 3D printing hot end heating device and control method. Background Technology

[0002] In the current 3D printing technology field, the hot-end heating device is the core component that ensures the melting and forming of the printing material. Existing technologies generally adopt contact heating methods such as resistance wire heating or thermocouple heating. A typical contact hot-end heating device mainly consists of a throat, an electric heating block, a heating element, a nozzle, and a fixing bracket. The throat runs vertically through the middle of the electric heating block to transport solid printing material. The electric heating block is mounted at the print head of the 3D printer via the fixing bracket. The heating element is usually a resistance wire or a thermocouple, which is directly embedded inside the electric heating block or closely attached to the outer wall of the electric heating block. The nozzle is fixedly connected to the lower end of the throat and attached to the bottom of the electric heating block. The printing material is transported to the nozzle through the throat, heats the electric heating block through the heating element, and then the electric heating block transfers heat to the throat and nozzle, achieving the melting of the printing material. This type of heating method transfers heat through direct contact between the heating element and the electric heating block, thereby enabling the printing material to reach the melting temperature, and has been widely used in conventional 3D printing scenarios.

[0003] However, existing contact heating methods have many inherent drawbacks. The contact conduction between the heating element and the electric heating block, and between the electric heating block and the throat and nozzle, results in significant heat loss during transfer, leading to low heating efficiency. The heat distribution of the electric heating block is easily affected by the tightness of the contact, causing uneven temperatures at the throat and nozzle, and localized overheating or temperature fluctuations on the hot-end surface, directly impacting the printing quality. Contact heating elements are prone to wear, oxidation, and corrosion under long-term high-temperature operating conditions, and the electric heating block may also loosen due to long-term thermal expansion and contraction, significantly shortening the equipment's lifespan. Furthermore, traditional heating methods rely on multi-stage heat conduction, resulting in a slow heating response speed, which cannot meet the demands of rapid heating and precise temperature control, limiting the application of high-temperature printing materials and high-precision printing scenarios.

[0004] As 3D printing technology advances towards higher temperatures and greater precision, higher demands are placed on the heating efficiency, temperature stability, and lifespan of hot-end heating devices. Therefore, a non-contact heating solution is urgently needed to address the problems of uneven heating, low energy efficiency, mechanical wear, and slow response inherent in existing contact heating methods, achieving rapid, uniform, and precise hot-end temperature control to adapt to the needs of different printing materials and printing scenarios. Summary of the Invention

[0005] The purpose of this invention is to provide a non-contact 3D printing hot-end heating device and control method to solve the problems existing in the current 3D printing hot-end heating technology mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a non-contact 3D printing hot end heating device, comprising a hot end body disposed at the print head of a 3D printer, a non-contact heating module group disposed around the outer periphery of the hot end body, a PID temperature control system integrated into the 3D printer control unit or the side of the hot end body, a temperature sensor attached to the outer wall of the hot end body, and a heat dissipation structure assembled on the outside of the hot end body and corresponding to the non-critical heating area.

[0007] The hot end body includes a hot end substrate and a nozzle. The non-contact heating module group integrates at least an induction heating module. The PID temperature control system is electrically connected to the non-contact heating module group and the temperature sensor. The PID temperature control system has built-in proportional control, integral control and derivative control logic. The PID temperature control system adjusts the output power of the non-contact heating module group in coordination with the proportional control, integral control and derivative control logic based on the difference between the real-time temperature fed back by the temperature sensor and the target temperature. The heat dissipation structure is used to dissipate the excess heat generated by the hot end body during the heating process.

[0008] Preferably, the hot end substrate is made of aluminum alloy or copper alloy, wherein the aluminum alloy is 6061 aluminum alloy and the copper alloy is C11000 copper; and the outer surface of the hot end substrate is anodized.

[0009] Preferably, the induction heating module includes an induction heating coil wound with high-frequency copper wire. The induction heating coil is evenly spirally arranged along the outer surface of the hot end substrate. The number of turns, coil diameter, and operating frequency range of the induction heating coil are adapted to the axial length, radial dimension, and material properties of the hot end substrate of the hot end body.

[0010] Preferably, the non-contact heating module group may also selectively integrate at least one of an infrared heating module, a laser heating module, and a microwave heating module;

[0011] The infrared heating module is used to emit infrared radiation to the surface of the hot end substrate of the hot end body.

[0012] The laser heating module is used to focus the laser beam onto a specific area of ​​the hot end body;

[0013] The microwave heating module is used to act on the polar molecules inside the printing material through electromagnetic waves.

[0014] Preferably, the PID temperature control system includes a proportional control unit, an integral control unit, and a derivative control unit, wherein:

[0015] The proportional control unit adjusts the heating power based on the error between the target temperature and the actual temperature;

[0016] The integral control unit eliminates long-term temperature errors in the system.

[0017] The differential control unit predicts the temperature trend based on the rate of temperature change and adjusts the power accordingly.

[0018] The response time of the PID temperature control system is ≤1 second.

[0019] Preferably, the temperature sensor is a thermocouple sensor or an RTD (resistance temperature detector) sensor, the detection end of the temperature sensor is in close contact with the hot end substrate of the hot end body, and the signal output end of the temperature sensor is electrically connected to the signal input end of the PID temperature control system.

[0020] Preferably, the heat dissipation structure is a heat sink or an air-cooling system; the heat sink is made of a high thermal conductivity metal material and is attached to the outer side of the hot end substrate of the hot end body; the air-cooling system includes a fan and an air guide shroud, the air outlet of the air guide shroud facing the non-heating critical area of ​​the hot end body; the outer surface of the hot end substrate of the hot end body is made of a high thermal conductivity material.

[0021] Preferably, the nozzle of the hot end body is made of stainless steel or tungsten alloy, wherein the stainless steel is 316 stainless steel and the tungsten alloy can withstand temperatures >3000℃; the inner wall and outlet end of the nozzle are precision machined.

[0022] A non-contact 3D printing hot-end heating control method, applied to any of the aforementioned non-contact 3D printing hot-end heating devices, the method comprising the following steps:

[0023] S1) Set the target temperature of the hot end body according to the characteristics of the 3D printing material, and input the target temperature parameter into the PID temperature control system;

[0024] S2) Start the non-contact heating module group, and at the same time, collect the actual temperature of the hot end substrate of the hot end body in real time through the temperature sensor, and transmit the actual temperature data to the PID temperature control system.

[0025] S3) The PID temperature control system calculates the error between the actual temperature and the target temperature, adjusts the heating power through the proportional control unit, eliminates the cumulative error through the integral control unit, and suppresses temperature fluctuations through the derivative control unit. It also outputs a power adjustment signal to the non-contact heating module group to dynamically adjust its output power.

[0026] S4) During the heating process, the excess heat of the hot end body is continuously dissipated through the heat dissipation structure, so that the temperature of the hot end body is stabilized within the target temperature ±ΔT until the printing process ends.

[0027] Where ΔT is the allowable range of temperature fluctuation.

[0028] Preferably, in step S2, the temperature sensor's temperature acquisition frequency is 10-50Hz, and the acquired actual temperature data is transmitted to the PID temperature control system after filtering.

[0029] Preferably, in step S3, when the non-contact heating module group integrates two or more heating modules, the PID temperature control system selectively activates the corresponding heating module or adjusts the power distribution ratio of each heating module based on the error amplitude between the actual temperature and the target temperature, wherein:

[0030] When the error amplitude is greater than 50℃, the induction heating module and the laser heating module are activated simultaneously.

[0031] When the error amplitude is ≤50℃ and >10℃, the induction heating module is activated separately.

[0032] When the error amplitude is ≤10℃, start the infrared heating module or microwave heating module for fine adjustment.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1) This application, through a non-contact heating design, fundamentally avoids the direct contact between the heating element and the hot end body in traditional contact heating, solving the problems of mechanical wear, oxidation and corrosion caused by contact heating, significantly extending the overall service life of the hot end heating device, reducing equipment maintenance costs, and integrating multiple non-contact heating technologies. Combined with induction heating coils evenly arranged along the hot end substrate, it can quickly and efficiently transfer heat, effectively improve heating uniformity, avoid local overheating or temperature fluctuations, provide a stable melting environment for printing materials, and ensure the molding accuracy and quality consistency of printed products.

[0035] 2) The PID temperature control system of this application has built-in proportional control, integral control and derivative control logic. With the help of a temperature sensor that collects high-frequency temperature data, it can achieve precise control of the hot end temperature. The temperature control system can quickly capture temperature changes and dynamically adjust the heating power. At the same time, by selectively starting and distributing power to different heating modules, it can further improve the temperature control accuracy and meet the needs of different scenarios such as conventional printing and high-temperature and high-precision printing.

[0036] 3) The hot end substrate of this application is made of aluminum alloy or copper alloy with high thermal conductivity and the surface is anodized. The nozzle is made of high temperature resistant stainless steel or tungsten alloy and is precision machined. Combined with the heat dissipation structure on the outside of the hot end, heat loss is reduced while avoiding overheating of the hot end. The energy-saving advantage of the non-contact heating method itself, combined with material selection and structural optimization, makes the heating energy efficiency of the device effectively improved compared with the traditional contact heating device, reducing power consumption and conforming to the development trend of energy conservation and environmental protection.

[0037] 4) The heating device and control method of this invention are highly adaptable and can flexibly adjust the target temperature, heating module combination and power distribution ratio according to the characteristics of the printing material. It can not only meet the heating requirements of conventional printing materials, but also adapt to high-temperature printing materials such as PEEK and ULTEM through the combination of laser heating module and high-temperature resistant nozzle, thus expanding the application scope of 3D printing technology and providing strong support for the technological upgrading of the 3D printing industry. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the heating device of this application;

[0039] Figure 2 This is a schematic diagram of the printhead structure of the heating device of this application;

[0040] Figure 3 This is a partial structural schematic diagram of the heating device of this application;

[0041] Figure 4 This is a flowchart of the heating control method of this application.

[0042] In the picture:

[0043] 1. 3D printer; 2. Hot end body; 21. Hot end substrate; 22. Nozzle; 3. Non-contact heating module group; 4. Temperature sensor; 5. Heat dissipation structure. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of the invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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 the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In the description of the invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] In the description of the invention, it should be noted that the execution order of the steps is not limited by the sequence number. The possible changes in the order of some steps, the synchronous execution of steps, and the split execution of steps are all within the scope of protection of this application.

[0048] Please see Figure 1-4 The present invention provides a technical solution: a non-contact 3D printing hot end heating device, including a hot end body disposed at the print head of the 3D printer, a non-contact heating module group disposed around the outer periphery of the hot end body, a PID temperature control system integrated into the 3D printer control unit or the side of the hot end body, a temperature sensor attached to the outer wall of the hot end body, and a heat dissipation structure assembled on the outside of the hot end body and corresponding to the non-critical heating area.

[0049] The hot end body includes a hot end substrate and a nozzle. The non-contact heating module group integrates at least an induction heating module. The PID temperature control system is electrically connected to the non-contact heating module group and the temperature sensor respectively. The PID temperature control system has built-in proportional control, integral control and derivative control logic. The PID temperature control system adjusts the output power of the non-contact heating module group in coordination with the proportional control, integral control and derivative control logic based on the difference between the real-time temperature fed back by the temperature sensor and the target temperature. The heat dissipation structure is used to dissipate the excess heat generated by the hot end body during the heating process.

[0050] Specifically, the non-contact heating module group is arranged around the hot end body. This layout ensures that the heating energy can be concentrated on the hot end substrate, avoiding the problems of long heat conduction paths and large heat loss in traditional contact heating. The temperature sensor is attached to the outer wall of the hot end body, which can capture the temperature changes of the hot end in real time and provide accurate data support for temperature control. The PID temperature control system is electrically connected to the heating module group and the temperature sensor, realizing closed-loop control of temperature feedback and power regulation, solving the shortcomings of slow response in traditional heating. The heat dissipation structure is assembled in the non-critical heating areas of the hot end, effectively dissipating excess heat and preventing the hot end from overheating and deforming.

[0051] Specifically, the hot-end substrate is fixedly connected to the nozzle to form a material conduction channel, ensuring the smooth transport of molten material. The non-contact heating module group integrates at least an induction heating module, fundamentally avoiding direct contact between the heating element and the hot end, thus solving problems such as mechanical wear and oxidation corrosion, and extending the overall service life of the device. This overall design organically combines non-contact heating, precise temperature control, and efficient heat dissipation, comprehensively solving problems such as uneven heating, low energy efficiency, and slow response in traditional heating methods, providing a stable and reliable hot-end heating foundation for 3D printing.

[0052] Specifically, please refer to the attached instruction manual. Figure 1-3 The 3D printer, hot end body, hot end substrate, nozzle, non-contact heating module group, temperature sensor, and heat dissipation structure of this application are shown in the figure. Components such as the PID temperature control system are not shown in the figure. In addition, the 3D printer is existing technology and will not be described in detail here.

[0053] Reference manual attached Figure 1-3 The heat dissipation structure is a heat sink or an air-cooling system; the heat sink is made of a high thermal conductivity metal material and is attached to the outside of the hot end substrate of the hot end body; the air-cooling system includes a fan and an air guide shroud, with the air outlet of the air guide shroud facing the non-heating critical area of ​​the hot end body; the outer surface of the hot end substrate of the hot end body is made of a high thermal conductivity material.

[0054] The hot-end substrate is made of either aluminum alloy or copper alloy, specifically 6061 aluminum alloy and C11000 copper alloy; both are anodized. Specifically, 6061 aluminum alloy possesses excellent thermal conductivity and light weight, along with outstanding corrosion resistance, making it suitable for most conventional 3D printing applications. It ensures rapid heat transfer while reducing the overall weight of the hot end and minimizing the load on the print head. C11000 copper alloy offers superior thermal conductivity, enabling rapid transfer of heat generated by the non-contact heating module, perfectly suited for high-temperature printing scenarios requiring efficient heat transfer and meeting the melting requirements of high-temperature printing materials. Anodizing significantly improves the hot-end substrate's high-temperature resistance, corrosion resistance, and surface hardness, effectively preventing deformation and oxidation during long-term high-temperature operation and further extending its lifespan. The choice of two materials provides a suitable solution for different printing needs, while anodizing enhances material durability, ensuring heating uniformity and device stability at the material level.

[0055] Reference manual attached Figure 3The induction heating module includes an induction heating coil wound with high-frequency copper wire. The induction heating coil is uniformly spirally arranged along the outer surface of the hot-end substrate. The number of turns, coil diameter, and operating frequency range of the induction heating coil are adapted to the axial length, radial dimension, and material properties of the hot-end substrate. Specifically, the high-frequency copper wire has excellent conductivity, and the coil wound with it can efficiently generate an alternating magnetic field, inducing uniform eddy currents within the hot-end substrate, thereby achieving rapid and uniform heating and solving the problem of localized overheating in traditional contact heating. The uniform spiral arrangement of the induction heating coil along the outer surface of the hot-end substrate ensures comprehensive and uniform magnetic field coverage, enabling synchronous heating of all parts of the hot-end substrate and avoiding uneven melting of the printing material due to temperature gradient differences. The adaptation of the number of turns, coil diameter, and operating frequency range of the coil to the axial length, radial dimension, and material properties of the hot-end substrate further optimizes the efficiency and uniformity of induction heating, ensuring that hot-end substrates of different sizes and materials can achieve suitable heating effects.

[0056] The non-contact heating module group also selectively integrates at least one of the following: infrared heating module, laser heating module, and microwave heating module;

[0057] The infrared heating module is used to emit infrared radiation onto the surface of the hot end substrate of the hot end body;

[0058] The laser heating module is used to focus the laser beam onto a specific area of ​​the hot-end body;

[0059] The microwave heating module is used to act on the polar molecules inside the printing material using electromagnetic waves.

[0060] Specifically, by selectively integrating multiple non-contact heating modules, the limitations of a single heating method are overcome, greatly expanding the device's adaptability and application scenarios. The infrared heating module, positioned towards the hot-end substrate surface, achieves large-area uniform heating through infrared radiation, suitable for heated beds and conventional printing materials. Its gentle and uniform heating avoids sudden local temperature changes. The laser heating module, with its laser output aligned with a specific area of ​​the hot-end substrate, focuses energy for high-precision local heating, meeting the melting requirements of high-temperature printing materials such as PEEK and ULTEM. Its precise temperature control ensures the stability of high-temperature printing. The microwave heating module, positioned along the material feed path, uses electromagnetic waves to act on the polar molecules within polymers and resins, achieving rapid material heating and adapting to the heating requirements of special materials. This selective integration of multiple heating modules allows the device to flexibly switch or combine heating methods according to the characteristics of the printing material and printing precision requirements. This ensures both high efficiency and stability for conventional printing and meets the personalized needs of high-temperature, high-precision, and special material printing, significantly improving the device's versatility and practicality.

[0061] Specifically, infrared heating modules, laser heating modules, and microwave heating modules can all be installed on the hot end body.

[0062] A PID temperature control system includes a proportional control unit, an integral control unit, and a derivative control unit, wherein:

[0063] The proportional control unit adjusts the heating power based on the error between the target temperature and the actual temperature;

[0064] The integral control unit eliminates long-term temperature errors in the system.

[0065] The differential control unit predicts the temperature trend based on the rate of temperature change and adjusts the power accordingly.

[0066] The response time of the PID temperature control system is ≤1 second.

[0067] Specifically, the proportional control unit adjusts the heating power based on the error between the target temperature and the actual temperature, enabling rapid response to temperature deviations and initial power adjustment. The integral control unit focuses on eliminating long-term temperature errors in the system, avoiding temperature drift caused by accumulated errors and ensuring long-term stable operation. The derivative control unit predicts temperature trends by monitoring the rate of temperature change and adjusts the heating power in advance, effectively suppressing temperature fluctuations and avoiding overshoot or hysteresis. These three components work together to form a complete closed-loop temperature control logic, completely solving the problems of low accuracy and large fluctuations in traditional temperature control methods. Simultaneously, the PID temperature control system has a response time of less than one second, rapidly capturing subtle changes in the hot-end temperature and adjusting the heating power accordingly, meeting the needs of rapid heating and precise temperature control. It provides reliable assurance for both rapid heating in conventional printing and stable temperature control in high-temperature printing.

[0068] The temperature sensor is either a thermocouple sensor or an RTD (Resistance Temperature Detector) sensor. The sensing end of the temperature sensor is tightly fitted to the hot end substrate, and the signal output end of the temperature sensor is electrically connected to the signal input end of the PID temperature control system. Specifically, both thermocouple sensors and RTD resistance temperature detectors possess high precision and high temperature resistance, enabling stable operation in the working environment of the 3D printed hot end and accurately capturing the actual temperature of the hot end substrate, avoiding temperature control deviations caused by insufficient sensor accuracy. The design of the temperature sensor's sensing end being tightly fitted to the hot end substrate shortens the temperature conduction path, reduces temperature acquisition lag, and ensures that the acquired temperature data accurately reflects the real-time temperature state of the hot end. The signal output end is electrically connected to the signal input end of the PID temperature control system, realizing real-time transmission of temperature data, allowing the PID temperature control system to promptly acquire temperature information and quickly adjust power accordingly. Accurate and real-time temperature data is a prerequisite for precise temperature control. This application ensures the reliability of the temperature control system from the data acquisition source, avoiding heating power adjustment errors caused by inaccurate temperature detection, and further improving the stability of the hot end temperature and the consistency of printing quality.

[0069] The nozzle of the hot-end body is made of stainless steel or tungsten alloy. The stainless steel is 316 stainless steel, and the tungsten alloy can withstand temperatures above 3000℃. The inner wall and outlet end of the nozzle are precision machined. Specifically, 316 stainless steel has high temperature resistance and good oxidation resistance, enabling it to work stably in normal high-temperature printing environments without easily deforming or corroding. Tungsten alloy can withstand extreme temperatures exceeding 3000 degrees Celsius, fully meeting the needs of high-temperature printing materials such as PEEK and ULTEM, breaking through the temperature limitations of traditional nozzles. The precision machining design of the inner wall and outlet end of the nozzle ensures a tight fit between the nozzle and the hot-end substrate, improving heat conduction performance and enabling the nozzle to respond quickly to temperature changes in the hot-end substrate, avoiding problems such as uneven material melting or clogging caused by poor heat conduction.

[0070] According to another aspect of this application, a non-contact 3D printing hot-end heating control method is also provided, the method comprising the following steps:

[0071] S1) Set the target temperature of the hot end body according to the characteristics of the 3D printing material, and input the target temperature parameter into the PID temperature control system;

[0072] S2) Start the non-contact heating module group, and at the same time, collect the actual temperature of the hot end substrate of the hot end body in real time through the temperature sensor, and transmit the actual temperature data to the PID temperature control system.

[0073] S3) The PID temperature control system calculates the error between the actual temperature and the target temperature, adjusts the heating power through the proportional control unit, eliminates the cumulative error through the integral control unit, and suppresses temperature fluctuations through the derivative control unit. It also outputs a power adjustment signal to the non-contact heating module group to dynamically adjust its output power.

[0074] S4) During the heating process, the excess heat of the hot end body is continuously dissipated through the heat dissipation structure, so that the temperature of the hot end body is stabilized within the target temperature ±ΔT until the printing process ends.

[0075] Where ΔT is the allowable range of temperature fluctuation.

[0076] Specifically, in the non-contact 3D printing hot-end heating control method of this application, temperature acquisition is performed simultaneously with the start of the heating module group in step S2, realizing synchronous heating and monitoring and ensuring real-time temperature data feedback. In step S3, the PID temperature control system outputs adjustment signals through the coordinated calculation of three control units to dynamically adjust the heating power, which not only quickly responds to temperature errors but also eliminates accumulated errors and suppresses temperature fluctuations, ensuring the accuracy of temperature regulation. In step S4, excess heat is continuously dissipated through the heat dissipation structure, keeping the hot-end temperature stable within the allowable fluctuation range and avoiding device damage or print quality degradation caused by overheating. The entire control method of this application has a clear logic and is interconnected, giving full play to the hardware advantages of the device. It realizes full-process control from temperature setting, heating start, real-time monitoring, dynamic adjustment to stable heat dissipation, effectively solving the problems of slow response, low accuracy, and poor stability of traditional heating control, and ensuring stable and efficient printing processes under different materials and scenarios.

[0077] In step S2, the temperature sensor's temperature acquisition frequency is 10-50Hz. The acquired actual temperature data is filtered and then transmitted to the PID temperature control system. Specifically, the 10-50Hz temperature acquisition frequency can capture temperature changes of the hot-end substrate at high frequency, and even minute temperature fluctuations can be detected in time, avoiding the loss of temperature information due to excessively low acquisition frequency, and providing more comprehensive temperature data support for the PID temperature control system. The filtered temperature data before transmission can effectively remove invalid signals caused by external interference or sensor errors, ensuring the accuracy of the data transmitted to the PID temperature control system. The combination of high-frequency acquisition and filtering enables the PID temperature control system to make adjustment decisions based on real and comprehensive temperature information, avoiding power adjustment errors caused by inaccurate data or information lag, further improving the accuracy and stability of temperature control, reducing the impact of temperature fluctuations on print quality, and is especially suitable for high-precision printing scenarios with high temperature sensitivity.

[0078] In step S3, when the non-contact heating module group integrates two or more heating modules, the PID temperature control system selectively activates the corresponding heating module or adjusts the power distribution ratio of each heating module based on the error amplitude between the actual temperature and the target temperature.

[0079] When the error amplitude is greater than 50℃, the induction heating module and the laser heating module are activated simultaneously.

[0080] When the error amplitude is ≤50℃ and >10℃, the induction heating module is activated separately.

[0081] When the error amplitude is ≤10℃, start the infrared heating module or microwave heating module for fine adjustment.

[0082] Specifically, the ID temperature control system selects the heating module based on the error amplitude between the actual temperature and the target temperature. When the error amplitude is large, both the induction heating module and the laser heating module are activated simultaneously, fully utilizing their rapid heating advantages to shorten the heating time and meet rapid heating requirements. When the error amplitude is moderate, only the induction heating module is activated, ensuring heating efficiency while avoiding energy waste. When the error amplitude is small, the infrared heating module or microwave heating module is activated for fine-tuning, utilizing their gentle and precise heating characteristics to stably maintain the target temperature. This dynamic adjustment method based on error amplitude fully leverages the performance advantages of different heating modules and achieves reasonable energy distribution. While quickly reaching the target temperature, it ensures stable and accurate temperature control, avoiding the energy inefficiency or temperature fluctuations caused by continuous operation of a single module. Furthermore, this adjustment logic allows the device to flexibly adjust according to different stages of the heating process, adapting to different temperature control requirements, further improving the device's energy efficiency and adaptability.

[0083] Example 1: Hot-end application of standard 3D printers

[0084] This embodiment is applied to a conventional FDM 3D printer, and adopts the non-contact 3D printing hot end heating device and control method of this application.

[0085] The hot end body is installed at the core of the 3D printer's print head. The hot end substrate is made of 6061 aluminum alloy with an anodized outer surface. The nozzle is made of 316 stainless steel and precision-machined. The hot end substrate and nozzle are fixedly connected to form a smooth material flow channel. A non-contact heating module group is arranged around the outer periphery of the hot end substrate, integrating an induction heating module and an infrared heating module. The induction heating coil is made of high-frequency copper wire, evenly spirally arranged along the outer surface of the hot end substrate. The coil has 15 turns, a diameter of 0.8mm, and an operating frequency of 20kHz, precisely matching the axial length of 80mm and radial dimension of 15mm of the 6061 aluminum alloy hot end substrate. A thermocouple sensor is used for temperature sensing, with the probe end tightly attached to the outer wall of the hot end substrate. The acquisition frequency is set to 20Hz, and the acquired data is filtered before being transmitted to the PID temperature control system. The PID temperature control system is integrated into the 3D printer control unit, with a response time of 0.8 seconds, and incorporates proportional control, integral control, and derivative control logic. The heat dissipation structure uses aluminum alloy heat sinks, which are fitted to the non-critical heating areas on the outer side of the hot-end body. When printing standard PLA material, the target temperature is set to 210℃. After activating the non-contact heating module, the temperature sensor collects and feeds back the temperature of the hot-end substrate in real time, and the PID temperature control system dynamically adjusts the power based on the error value. In the initial stage, the error range between the actual temperature and the target temperature is 35℃, so the induction heating module is activated separately for rapid heating; when the error range drops to 8℃, the infrared heating module is switched on for fine-tuning, and the hot-end temperature eventually stabilizes within the range of 210℃±2℃.

[0086] This embodiment improves heating efficiency by 55% compared to traditional contact heating devices through the coordinated work of various components, completely avoids mechanical wear problems, and produces printed products with high forming accuracy, smooth surface, and no local melting unevenness.

[0087] Example 2: High-Temperature Printing Application

[0088] This embodiment is adapted to high-temperature printing materials such as PEEK ULTEM and adopts the non-contact 3D printing hot end heating device and control method of this application.

[0089] The hot-end substrate is made of C11000 copper alloy, utilizing its excellent thermal conductivity to rapidly transfer heat. The nozzle is made of tungsten alloy, capable of withstanding temperatures above 3000℃, meeting the requirements for melting high-temperature materials. The non-contact heating module integrates an induction heating module, a laser heating module, and an infrared heating module. The induction heating coil has 20 turns, a coil diameter of 1.0mm, and an operating frequency of 30kHz, adapting to the C11000 copper alloy hot-end substrate with an axial length of 100mm and a radial dimension of 20mm. The laser heating module's laser output end is aligned with the critical heating area of ​​the hot-end substrate near the nozzle, while the infrared heating module is positioned towards the central area of ​​the hot-end substrate. The temperature sensor uses an RTD resistance temperature detector, sampling at a frequency of 30Hz. The data is filtered before being transmitted to the PID temperature control system. The heat dissipation structure employs an air-cooling system, with the fan fixed to the 3D printer's hot-end mounting base, and the air outlet of the air guide shroud facing the upper non-heated area of ​​the hot-end body. When printing PEEK material, the target temperature is set to 380℃. After starting the heating module group, if the initial actual temperature differs from the target temperature by 90℃, the PID temperature control system simultaneously activates the induction heating module and the laser heating module to rapidly increase the temperature. When the error drops to 45℃, the laser heating module is turned off, while the induction heating module continues to raise the temperature. When the error is ≤10℃, the infrared heating module is switched on for fine-tuning. Throughout the heating process, the PID temperature control system responds quickly to errors through the proportional control unit, eliminates accumulated deviations through the integral control unit, and suppresses temperature fluctuations through the derivative control unit. Ultimately, the hot end temperature stabilizes within the range of 380℃±1℃, meeting the high-temperature melting requirements of PEEK material.

[0090] This embodiment utilizes heat

[0091] The selection of high-temperature compatible materials for the substrate and nozzle, along with the collaborative startup logic of multiple heating modules, successfully broke through the temperature limitations of traditional heating devices, enabling stable printing of high-temperature materials. The mechanical properties and forming quality of the printed products both reached high industry standards, and the device showed no oxidation or deformation after long-term high-temperature operation, significantly extending its service life.

[0092] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A non-contact 3D printing hot-end heating device, characterized in that, It includes a hot end body set at the print head of the 3D printer, a non-contact heating module group surrounding the outer periphery of the hot end body, a PID temperature control system integrated into the 3D printer control unit or the side of the hot end body, a temperature sensor attached to the outer wall of the hot end body, and a heat dissipation structure assembled on the outside of the hot end body and corresponding to the non-critical heating area. The hot end body includes a hot end substrate and a nozzle. The non-contact heating module group integrates at least an induction heating module. The PID temperature control system is electrically connected to the non-contact heating module group and the temperature sensor. The PID temperature control system has built-in proportional control, integral control and derivative control logic. The PID temperature control system adjusts the output power of the non-contact heating module group in coordination with the proportional control, integral control and derivative control logic based on the difference between the real-time temperature fed back by the temperature sensor and the target temperature. The heat dissipation structure is used to dissipate the excess heat generated by the hot end body during the heating process.

2. The non-contact 3D printing hot-end heating device according to claim 1, characterized in that, The hot end substrate is made of aluminum alloy or copper alloy, and the outer surface of the hot end substrate is anodized.

3. The non-contact 3D printing hot-end heating device according to claim 1, characterized in that, The induction heating module includes an induction heating coil wound with high-frequency copper wire. The induction heating coil is evenly spirally arranged along the outer surface of the hot end substrate. The number of turns, coil diameter, and operating frequency range of the induction heating coil are adapted to the axial length, radial dimension, and material properties of the hot end substrate of the hot end body.

4. The non-contact 3D printing hot-end heating device according to claim 1, characterized in that, The non-contact heating module group also selectively integrates at least one of an infrared heating module, a laser heating module, and a microwave heating module; The infrared heating module is used to emit infrared radiation to the surface of the hot end substrate of the hot end body. The laser heating module is used to focus the laser beam onto a specific area of ​​the hot end body; The microwave heating module is used to act on the polar molecules inside the printing material through electromagnetic waves.

5. The non-contact 3D printing hot-end heating device according to claim 1, characterized in that, The PID temperature control system includes a proportional control unit, an integral control unit, and a derivative control unit, wherein: The proportional control unit adjusts the heating power based on the error between the target temperature and the actual temperature; The integral control unit eliminates long-term temperature errors in the system. The differential control unit predicts the temperature trend based on the rate of temperature change and adjusts the power accordingly. The response time of the PID temperature control system is ≤1 second.

6. The non-contact 3D printing hot-end heating device according to claim 1, characterized in that, The sensing end of the temperature sensor is in close contact with the hot end substrate of the hot end body, and the signal output end of the temperature sensor is electrically connected to the signal input end of the PID temperature control system.

7. The non-contact 3D printing hot-end heating device according to claim 1, characterized in that, The nozzle of the hot end body is made of stainless steel or tungsten alloy.

8. A non-contact 3D printing hot-end heating control method, characterized in that, The method, applied to any of the non-contact 3D printing hot-end heating devices according to claims 1-7, comprises the following steps: S1) Set the target temperature of the hot end body according to the characteristics of the 3D printing material, and input the target temperature parameter into the PID temperature control system; S2) Start the non-contact heating module group, and at the same time, collect the actual temperature of the hot end substrate of the hot end body in real time through the temperature sensor, and transmit the actual temperature data to the PID temperature control system. S3) The PID temperature control system calculates the error between the actual temperature and the target temperature, adjusts the heating power through the proportional control unit, eliminates the cumulative error through the integral control unit, and suppresses temperature fluctuations through the derivative control unit. It also outputs a power adjustment signal to the non-contact heating module group to dynamically adjust its output power. S4) During the heating process, the excess heat of the hot end body is continuously dissipated through the heat dissipation structure, so that the temperature of the hot end body is stabilized within the target temperature ±ΔT until the printing process ends. Where ΔT represents the allowable range of temperature fluctuations.

9. The non-contact 3D printing hot-end heating control method according to claim 8, characterized in that, In step S2, the temperature sensor acquires temperature data at a frequency of 10-50Hz. The acquired actual temperature data is then filtered and transmitted to the PID temperature control system.

10. The non-contact 3D printing hot-end heating control method according to claim 8, characterized in that, In step S3, when the non-contact heating module group integrates two or more heating modules, the PID temperature control system selectively activates the corresponding heating module or adjusts the power distribution ratio of each heating module based on the error amplitude between the actual temperature and the target temperature. When the error amplitude is greater than 50℃, the induction heating module and the laser heating module are activated simultaneously. When the error amplitude is ≤50℃ and >10℃, the induction heating module is activated separately. When the error amplitude is ≤10℃, start the infrared heating module or microwave heating module for fine adjustment.

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