Composite material additive manufacturing printing nozzle self-cleaning device

Abstract

The invention provides a self-cleaning device for a composite material additive manufacturing printing spray head. The outer side of a spray nozzle is connected with an annular rotary driving part through a flange connecting structure; wherein a two-degree-of-freedom mechanical arm executing mechanism is suspended below the annular rotary driving piece; wherein one end of the two-degree-of-freedom mechanical arm executing mechanism is connected with the telescopic through needle self-cleaning system, and the other end of the two-degree-of-freedom mechanical arm executing mechanism is connected with the automatic rotary nozzle wiping device; the telescopic cleaning needle self-cleaning system comprises a cleaning needle base, a telescopic probe rod and a scraping rod; and the automatic rotary nozzle wiping device comprises a cleaning sponge or a scraping blade. By means of the built-in telescopic cleaning needle, when blockage is detected, the nozzle hole is automatically pierced to remove residues, and the complexity of manual disassembly and cleaning is avoided.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing of composite materials, and specifically to a self-cleaning device for a printing nozzle in additive manufacturing of composite materials. Background Art

[0002] In the field of additive manufacturing, additive manufacturing printing realizes the conversion from a digital model to a physical component by layer-by-layer stacking of media. As the core execution component of this technology, the melt extrusion printing nozzle occupies an important position in rapid prototyping manufacturing, personalized product processing, and multi-disciplinary cross-application scenarios due to its open structure and high cost performance characteristics. This type of nozzle works based on the phase change principle of thermoplastic materials, and the specific implementation process includes process steps such as continuous feeding of the filament, gradient heating and melting, and micro-hole precision extrusion.

[0003] In conventional melt extrusion operations, there are several technical bottlenecks affecting the continuity of forming: firstly, under the action of the axial temperature gradient in the barrel-type heat conduction system, it is easy to cause non-uniform melting of the core layer and surface layer of the filament, and solid particles that have not completely undergone a phase change form a plug-like body in the flow channel; secondly, the thermally stable inclusions endogenous to the raw material generate phase interface migration during the high-pressure extrusion process, forming a dynamic deposition effect in the flow channel constriction area. The intermittent blockage problem of the flow channel caused by the above two factors will directly cause process defects such as deterioration of the interlayer bonding force of the print and a decrease in the forming surface quality.

[0004] Current maintenance solutions mostly adopt physical intervention cleaning methods. After completely disassembling the nozzle assembly, a rigid probe is used to mechanically dredge the conical flow channel. This operation mode has multiple technical limitations: firstly, frequent disassembly and assembly easily cause thermal fatigue damage to the sealing interface between the nozzle and the heating module; secondly, the geometric characteristics of the special-shaped flow channel make it difficult for traditional cleaning tools to reach some areas, and it is difficult to completely remove impurities in the entire path; furthermore, offline cleaning operations will interrupt the continuous production process and significantly reduce the overall utilization rate of the equipment. Therefore, there is an urgent need to develop an integrated in-situ cleaning system to achieve non-destructive flow channel maintenance and real-time process performance recovery. Summary of the Invention

[0005] To solve the above problems, the present invention discloses a self-cleaning device for a printing nozzle in additive manufacturing of composite materials. When a blockage is detected, the built-in retractable needle self-cleaning system automatically pierces into the nozzle hole to remove residues, avoiding the cumbersome operation of manual disassembly and cleaning. At the same time, an automatic rotating nozzle wiping device is used to remove the overflow material on the outer wall of the nozzle, avoiding the risk of blockage caused by long-term accumulation of impurities.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: A self-cleaning device for a printing nozzle in additive manufacturing of composite materials, comprising: a nozzle built-in retractable needle self-cleaning system and an automatic rotating nozzle wiping device; The nozzle built-in retractable needle self-cleaning system comprises an extrusion component, a nozzle component and a heat dissipation component connected to the nozzle component; The nozzle assembly includes a throat connected to the extrusion assembly, a heat transfer block arranged at the lower end of the throat, a nozzle connected to the heat transfer block, a telescopic probe arranged inside the nozzle, and a rotatable scraper on the telescopic probe; The retractable needle self-cleaning system is driven to retract by a stepping motor, and automatically penetrates into the nozzle hole to remove residue and triggers the rotation of the rotary scraper rod when a blockage is detected; The automatic rotating nozzle wiping device comprises a base and a cleaning sponge. An annular rotating driving member is designed on the periphery of the nozzle to cooperate with the cleaning sponge to scrape off the overflow from the outer wall of the nozzle.

[0007] On the basis of the above technical solution, the present invention also provides the following optional technical solution: In an optional solution: the cleaning sponge is replaced with a scraper blade, and the periphery of the nozzle is cleaned by controlling the rotation of the scraper blade, and a hole is opened on the surface of the scraper blade, and a negative pressure suction nozzle is connected to achieve waste recovery.

[0008] In an optional solution: the single nozzle structure is designed as a double nozzle structure, and a circular rotary drive member and a double-channel cleaning system are arranged on the periphery of the double nozzle.

[0009] In an optional solution: an elastic supporting base is added under the cleaning sponge, and wiping pressure control is achieved through a pressure sensor.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention uses a built-in retractable needle self-cleaning system to automatically penetrate the nozzle hole to remove residues when blockage is detected, without relying on manual judgment and operation, avoiding the tedious operation of manual disassembly and cleaning, with a high degree of intelligence, and can solve the problem of internal blockage of the nozzle more timely and effectively.

[0011] 2. The present invention adopts a servo motor to drive the annular rotary drive part, and links the cleaning sponge assembly to move synchronously. It can not only remove the overflow on the outer wall of the nozzle through the automatic rotating nozzle wiping device, but also use the retractable needle self-cleaning system to clean deeply inside the nozzle. The cleaning range covers inside and outside the nozzle, which can more comprehensively avoid the risk of blockage caused by long-term accumulation of impurities.

[0012] 3. The self-cleaning device for the composite material additive manufacturing printing nozzle of the present invention can complete cleaning during the printing process or in short intervals, significantly reducing equipment downtime, better ensuring the continuous and stable operation of the additive manufacturing printing nozzle, and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0014] Figure 2 It is a schematic structural diagram of a nozzle self-cleaning device containing a cleaning sponge.

[0015] Figure 3 It is Figure 2 The partial enlarged view at location A in

[0016] Figure 4 It is a schematic structural diagram of the overall structure of a retractable needle self-cleaning system.

[0017] Figure 5 It is a sectional view of the nozzle structure.

[0018] Figure 6 It is a schematic structural diagram of a nozzle self-cleaning device containing a scraping blade and a negative pressure suction nozzle.

[0019] Figure 7 It is Figure 6 The schematic structural diagram of the scraping blade and the negative pressure suction nozzle in

[0020] Figure 8 It is a schematic structural diagram of a double-nozzle and double-channel cleaning device.

[0021] Figure 9 It is a schematic structural diagram of a cleaning sponge device containing an elastic supporting base.

[0022] List of reference numerals: 1 Throat tube; 2 Heat sink; 3 Heat transfer block; 4 Heating block; 5 Temperature sensor; 6 Nozzle; 7 Ring rotary drive; 8 First robotic arm; 9 First rotary pair; 10 Second rotary pair; 11 Second robotic arm; 12 Third rotary pair; 13 Fourth rotary pair; 14 Cleaning sponge; 15 Anti-blocking rotating head; 16 Telescopic probe; 17 Scraping rod; 18 Needle base; 19 Scraping blade; 20 Negative pressure adsorption device; 21 Flexible conduit; 22 Double-ring drive module; 23 Elastic supporting base; 24 Preloaded spiral spring. Detailed implementation manners

[0023] The present invention will be further clarified below in conjunction with the drawings and the detailed implementation manners. It should be understood that the following detailed implementation manners are only used to illustrate the present invention and not to limit the scope of the present invention. It should be noted that the terms "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings, and the terms "inner" and "outer" refer to the directions towards or away from the geometric center of a specific component respectively. Embodiment

[0024] As Figures 1 - 5As shown in the figure, a self-cleaning device for an additive manufacturing printing nozzle of a composite material disclosed in this embodiment includes the following cooperating units: The base structure includes a throat assembly 1 extending axially. A heat sink assembly 2 is coaxially sleeved on the outer peripheral surface of the throat assembly 1. The output end of the throat assembly 1 is thermally coupled to a heat transfer block 3, and a resistive heating block 4 and an embedded temperature sensor 5 are integrated in the heat transfer block 3. The axial output end of the heat transfer block 3 is connected to a nozzle 6, and an annular rotary drive member 7 is assembled through a flange connection structure. A two-degree-of-freedom robotic arm actuator is suspended below the annular rotary drive member 7. Among them, the first robotic arm 8 and the second rotary pair 10 form a planar positioning mechanism through the first rotary pair 9 to adjust and control the spatial pose of the needle clearing base 18. The second robotic arm 11 drives the cleaning sponge 14 through the third rotary pair 12 and the fourth rotary pair 13 in a linkage manner. The rotary pair is driven by a servo motor to achieve contact cleaning of the outer surface of the nozzle 6.

[0025] A telescopic probe 16 driven by a linear actuator is assembled on the upper part of the needle clearing base 18. An anti-clogging rotating head 15 is integrated at the top of the probe. A plurality of elastic scraping rods 17 are radially distributed on the anti-clogging rotating head 15. The scraping rods 17 generate a circumferential scraping effect under the rotation drive of the anti-clogging rotating head 15 to effectively remove the adhered residues in the inner cavity of the nozzle. Embodiment

[0026] This embodiment is a configuration improvement embodiment of Embodiment 1, and the same functional components use the reference numerals of Embodiment 1. The following focuses on the differential technical features: As Figures 6 - 7 shown, a scraping blade 19 is provided at the end of the fourth rotary pair 13. A diversion channel is axially opened through the scraping blade 19 and is fluidly connected to a negative pressure adsorption device 20. The negative pressure adsorption device 20 is coupled to an external vacuum generating system through a flexible conduit 21 to form an integrated working mode of material peeling and recovery. Embodiment

[0027] As Figure 2 and Figure 8 shown, this embodiment optimizes the architecture on the basis of Embodiment 1. Specifically, the configuration of the annular rotary drive member 7 evolves from a single-piece annular structure to a double-ring drive module 22. A split cleaning nozzle 6 is provided at the center of each annular drive unit to form a dual-channel parallel cleaning system with the ability to avoid spatial interference. Embodiment

[0028] As Figure 2 and Figure 9As shown in the figure, the automatic rotating mouth wiping device includes the following innovative structural configurations: The elastic supporting base 23 is fixedly connected to the end of the second robotic arm 11 through a force feedback coupling connector, and a pre-compressed helical spring 24 is integrated inside the base; the cleaning sponge 14 is floatingly assembled with the elastic supporting base 23 to construct a contact pressure adaptive adjustment mechanism, and the wiping pressure is controlled by a pressure sensor.

[0029] The technical means disclosed in the solution of the present invention are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features.

Claims

1. An automatic cleaning device for a printing nozzle in additive manufacturing of composite materials, characterized in that: An annular rotary drive member (7) is connected to the outside of the nozzle (6) via a flange connection structure; a dual-degree-of-freedom robotic arm actuator is suspended below the annular rotary drive member (7); one end of the dual-degree-of-freedom robotic arm actuator is connected to a retractable needle self-cleaning system and the other end is connected to an automatic rotating nozzle wiping device; the retractable needle self-cleaning system comprises a needle base (18), a retractable probe rod (16) and a scraper rod (17); and the automatic rotating nozzle wiping device comprises a cleaning sponge (14) or a scraping blade (19).

2. The self-cleaning device for an additive manufacturing print head of a composite material according to claim 1, characterized in that: The dual-degree-of-freedom mechanical arm actuator comprises a first mechanical arm (8) and a second mechanical arm (11), wherein the first mechanical arm (8) forms a planar positioning mechanism through a first rotating pair (9) and a second rotating pair (10), and the second mechanical arm (11) controls the cleaning sponge (14) in linkage with a third rotating pair (12) and a fourth rotating pair (13), and the rotating pair is driven by a servo motor to achieve contact cleaning of the outer surface of the nozzle (6).

3. The self-cleaning device for an additive manufacturing printing nozzle of a composite material according to claim 1, characterized in that: The upper part of the needle base (18) is equipped with a telescopic probe rod (16) driven by a linear actuator, and the top end of the telescopic probe rod (16) is integrated with an anti-blocking head (15); the anti-blocking head (15) is radially distributed with a plurality of elastic scraping rods (17), and the elastic scraping rods (17) produce a circumferential scraping effect under the rotation drive of the anti-blocking head (15) to remove adherent residues in the inner cavity of the nozzle (6).

4. The self-cleaning device for an additive manufacturing printing nozzle of a composite material according to claim 1, wherein: A scraper blade (19) is provided at the end of the fourth rotating pair (13); the scraper blade (19) axially penetrates to open a flow guide channel and is fluidically connected to a negative pressure adsorption device (20); the negative pressure adsorption device (20) is coupled to an external vacuum generation system via a flexible conduit (21) to form a material stripping-recovery integrated working mode.

5. The self-cleaning device for an additive manufacturing printing nozzle of a composite material according to claim 1, wherein: The configuration of the annular rotary drive member (7) evolves from a single annular structure to a bilaterally symmetrical double-annular drive module (22), wherein each annular drive unit corresponds to the left and right sides of the split nozzle (6), and through rotational drive, the cleaning sponge (14) performs 360° cleaning along the outer wall of the nozzle (6), thereby achieving full coverage and cleaning of the outer surface of the nozzle (6).

6. The self-cleaning device for an additive manufacturing printing nozzle of a composite material according to claim 1, characterized in that: The automatic rotating mouth-wiping device also includes an elastic supporting base (23); wherein the elastic supporting base (23) is fixedly connected to the second mechanical arm (11) through a force feedback coupling connector, and a pre-stressed coil spring (24) is integrated inside the elastic supporting base (23); the cleaning sponge (14) and the elastic supporting base (23) form a floating assembly.

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