A local heating 3D printing head usable for high melting point materials

Abstract

A kind of local heating type 3D printing head for high melting point material, including extrusion head mechanism;The middle part below the extrusion head mechanism is connected with printing nozzle, the heating mechanism gradually decreasing from the middle part to the edge temperature is connected below the extrusion head mechanism, and the edge and the middle part below the heating mechanism are connected with temperature sensor.The utility model adopts the heating mechanism gradually decreasing from the middle part to the edge temperature below the extrusion head mechanism, specifically sets local heating cover near printing nozzle, forms the temperature gradient of center high, periphery low by the mode of helical heating tube or spherical cap heating cover heat reflection, different from traditional whole cavity hot air circulation heating mode, can effectively reduce energy consumption.

Description

Technical Field

[0001] This utility model relates to the field of 3D printing technology, specifically to a local heating 3D printing head that can be used for high melting point materials. Background Technology

[0002] In the field of 3D printing technology, many high-performance engineering plastic materials have high melting points, such as PEEK and PPS. Taking PEEK as an example, it is a high-performance engineering thermoplastic with high strength, high heat resistance, and excellent corrosion resistance, and is widely used in aerospace, biomedicine, and high-end manufacturing. However, PEEK material has a high melting point (about 343°C), a narrow molding window, and weak interlayer bonding. Conventional 3D printing equipment has difficulty in stably controlling its thermal environment, which can easily lead to problems such as warping, delamination, poor molding, and dimensional deviations. Current high-temperature 3D printing equipment uses a whole-chamber hot air circulation heating method to achieve a high-temperature environment, which has problems such as slow system start-up, high energy consumption, complex structure, large equipment size, small printing size range, high manufacturing cost, and stringent temperature resistance requirements for electronic components.

[0003] Currently, 3D printing equipment for high-performance engineering plastics such as PEEK mostly adopts a heating method of hot air circulation throughout a closed chamber, maintaining the entire chamber at a high temperature through hot air convection. However, this technology has the following drawbacks:

[0004] 1.1 The whole cavity heating method needs to maintain the entire printing space above 200°C to ensure the molding quality of the top layer, but this leads to overheating of the bottom and non-critical areas, resulting in heat waste and high system energy consumption;

[0005] 1.2 The need for multi-layer insulation materials, hot air circulation system, high-temperature resistant electronic components and motors or heat insulation design, etc., significantly increases the overall cost of the machine;

[0006] 1.3 A larger printing chamber has a greater impact on heat preservation and energy consumption, which limits the printing size range of 3D printing equipment and makes it impossible to meet the 3D printing needs of some large-sized parts. Utility Model Content

[0007] The present invention aims to solve the above-mentioned technical problems by providing a local heating 3D printing head that can be used for high melting point materials. The 3D printing head adopts a heating mechanism in which the temperature gradually decreases from the center to the edge, that is, a local high temperature chamber is constructed near the nozzle below the extrusion head mechanism.

[0008] To solve the above-mentioned technical problems, the present invention provides a technical solution for a locally heated 3D printing head that can be used for high melting point materials:

[0009] It includes an extrusion head mechanism; a printing nozzle is connected to the lower center of the extrusion head mechanism, and a heating mechanism with a gradually decreasing temperature from the center to the edge is connected to the lower center of the extrusion head mechanism, and temperature sensors are connected to the lower edge and the center of the heating mechanism.

[0010] The heating mechanism is a heating cover; a heating tube is connected to the bottom of the heating cover.

[0011] The heating element is spiral-shaped, and the spacing between the heating elements increases continuously from the center outwards along the spiral; the heating cover is circular.

[0012] The heating cover is spherical, and the heating tube is connected to the center below the heating cover.

[0013] The two temperature sensors are respectively installed on the edge and the middle of the heating cover.

[0014] The extrusion head mechanism is also equipped with a cooling fan.

[0015] The technical effects that this utility model can achieve are:

[0016] 1. The extrusion head mechanism of this utility model adopts a heating mechanism with the temperature gradually decreasing from the center to the edge. Specifically, a local heating cover is set near the printing nozzle. A temperature gradient with a high center and a low periphery is formed by heat reflection through a spiral heating tube or a spherical heating cover. This is different from the traditional hot air circulation heating method of the entire cavity, which can effectively reduce energy consumption.

[0017] 2. Temperature sensors are installed at the center and edge of the heating cover. Through the temperature feedback control system, the temperature of different areas of the heating cover can be monitored and adjusted in real time to ensure that the temperature gradient between the center and the edge is kept stable within the set range, thereby achieving precise control of the temperature of local hot areas. Attached Figure Description

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0019] Figure 1 This is a schematic diagram of the structure of a local heating 3D printing head that can be used for high melting point materials (using a circular heating cover);

[0020] Figure 2 This is a schematic diagram showing the heating element in a spiral shape;

[0021] Figure 3 This is a schematic diagram of the structure of a local heating 3D printing head that can be used for high melting point materials (using a spherical heating cover);

[0022] Figure 4This is a schematic diagram showing the specific relationship between the temperature of the heating cover and the radial distance of this utility model. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings.

[0024] See Figures 1 to 4 .

[0025] A local heating 3D printing head for high melting point materials includes an extrusion head mechanism 2, a printing nozzle connected to the lower center of the extrusion head mechanism 2, a heating mechanism whose temperature gradually decreases from the center to the edge connected to the lower part of the extrusion head mechanism 2, and temperature sensors 4 connected to the lower edge and the center of the heating mechanism; specifically, the heating mechanism is a heating cover 3, and a heating tube 6 is connected to the lower part of the heating cover 3; preferably, a cooling fan 7 is also installed on the extrusion head mechanism 2.

[0026] Specifically regarding the heating mechanism, this utility model has the following two specific embodiments:

[0027] Example 1

[0028] The heating element 6 is spiral-shaped, and the spacing between the heating elements 6 increases continuously from the center outwards along the spiral. The heating cover 3 is circular, and two temperature sensors 4 are respectively installed on the edge and the center of the heating cover 3.

[0029] Example 2

[0030] The heating cover 3 is spherical, and the heating tube 6 is connected to the center below the heating cover 3; two temperature sensors 4 are respectively installed on the edge and the middle of the heating cover 3.

[0031] The two embodiments described above employ a localized heating design for the printing nozzle. Specifically, a localized heating shroud 3 is placed near the printing nozzle. A temperature gradient with a high center and a low periphery is formed through heat reflection using spiral heating tubes 6 or spherical heating shroud 3. This differs from the traditional method of circulating hot air throughout the entire cavity, effectively reducing energy consumption. Furthermore, temperature sensors 4 are placed at the center and edge of the heating shroud 3, respectively. Through a temperature feedback control system, the temperature of different areas of the heating shroud 3 can be monitored and adjusted in real time, ensuring that the temperature gradient between the center and the edge remains stably within the set range, thereby achieving precise control of the temperature of the localized hot zone.

[0032] For the specific relationship between the temperature of heating cover 3 and the radial distance, please refer to [reference needed]. Figure 4 The temperature distribution of the heating cover 3 is closely related to the radial distance: the temperature is highest near the center and gradually decreases as the distance from the center increases.

[0033] The operating principle of this utility model is as follows: This invention adopts a wire feeding structure. The printing wire 1 enters the extrusion head mechanism 2 through the feed port. During the printing process, the wire 1 is melted when it passes through the heating block inside the extrusion head mechanism 2, and then extruded onto the printing platform 5. The printing platform 5 moves along the Z-axis direction to realize the layering and forming during the printing process.

[0034] To achieve thermal environment stability and improve interlayer bonding strength during the material melting process, this invention sets a heating cover 3 near the extruder (i.e., the printing nozzle). The heating cover 3 is circular or spherical. By setting up reasonable heating tubes 6, the heating cover 3 is arranged from the center to the outer edge in a manner with heating density from high to low, thereby creating a heating environment with radial thermal radiation gradient. This allows the printing area to obtain a continuous and uniformly varying thermal radiation intensity, thereby optimizing the molding quality. The circular disk structure can provide a symmetrical and consistent thermal radiation distribution in any direction of movement, which is beneficial to ensuring the uniformity of the heating effect in all directions and obtaining a uniform variation in thermal radiation intensity.

[0035] To further improve the real-time response and precision control of the heating system, two temperature sensors 4 are installed on the heating cover 3, respectively located in the central and outer edge areas of the heating cover 3, for real-time detection of temperature data at different radial positions; combined with the information collected by the temperature sensors, the power output of the heating pipe is dynamically adjusted through the feedback control system, thereby achieving stable control of the temperature field in the local heating zone to meet the precise temperature environment requirements of the high-performance thermoplastic material molding process.

[0036] Compared with existing PEEK printing devices that use full-cavity constant temperature (e.g., 200℃), the local heating 3D printing head of this invention, which can be used for high melting point materials, has significant advantages in the following aspects:

[0037] 1. High energy utilization efficiency

[0038] Traditional whole-cavity heating requires heating the entire printing cavity (typically several to tens of liters) to maintain ambient temperature, resulting in high heat loss and slow start-up. In contrast, the localized chamber heating structure proposed in this application only heats the critical area around the printing nozzle, concentrating heat and responding quickly, significantly reducing heating energy consumption.

[0039] 2. The temperature gradient is controllable and symmetrically distributed.

[0040] Whole-cavity heating often creates a uniform field, making it difficult to achieve a gradient directional temperature field. However, this invention constructs a radially symmetrical temperature distribution of "high temperature at the center and low temperature at the periphery" through the curved surface thermal radiation of the spiral heating tube 6 and the spherical heating cover 3. This better meets the requirements of crystalline polymers such as PEEK for controlling the crystallization rate during the cooling stage, effectively optimizing the crystallization behavior and improving the density and mechanical properties of the molded parts.

[0041] 3. Independent of cavity structure, highly adaptable

[0042] Traditional whole-cavity heating solutions heavily rely on a closed cavity structure, whose operation is limited by cavity volume, airtightness, and thermal circulation system configuration, placing high demands on the equipment's insulation and sealing performance. In small-scale equipment or multi-axis linkage systems with limited space, whole-cavity heating structures are difficult to integrate effectively. Furthermore, for additive manufacturing of large-size PEEK parts, constructing large heating cavities is not only costly and complex in design, but also presents significant challenges in achieving thermal equilibrium control. In contrast, the local heating module proposed in this invention is an independent functional unit that can operate independently of the cavity structure. It is suitable for various open platforms and heterogeneous printing equipment, significantly expanding the molding boundaries of high-performance materials such as PEEK in diverse application scenarios.

Claims

1. A local heating 3D printing head for high melting point materials, comprising an extrusion head mechanism (2); a printing nozzle is connected to the lower center of the extrusion head mechanism (2), characterized in that: The extrusion head mechanism (2) is connected to a heating mechanism whose temperature gradually decreases from the center to the edge, and temperature sensors (4) are connected to the lower edge and the center of the heating mechanism.

2. The local heating 3D printing head for high melting point materials according to claim 1, characterized in that: The heating mechanism is a heating cover (3); a heating tube (6) is connected below the heating cover (3).

3. A locally heated 3D printing head for high-melting-point materials according to claim 2, characterized in that: The heating tube (6) is spiral-shaped, and the spacing between the heating tubes (6) increases continuously from the middle to the outside along the spiral; the heating cover (3) is circular.

4. A locally heated 3D printing head for high-melting-point materials according to claim 2, characterized in that: The heating cover (3) is spherical, and the heating tube (6) is connected to the center below the heating cover (3).

5. A local heating 3D printing head for high melting point materials according to claim 3 or 4, characterized in that: The two temperature sensors (4) are respectively installed on the edge and the middle of the heating cover (3).

6. A local heating 3D printing head for high melting point materials according to claim 1, characterized in that: A cooling fan (7) is also installed on the extrusion head mechanism (2).

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