CN114147953B

CN114147953B - Additive manufacturing equipment and method based on material extrusion and photocuring composite molding

Info

Publication number: CN114147953B
Application number: CN202111448308.9A
Authority: CN
Inventors: 徐杰; 何鑫
Original assignee: Jiangnan University
Current assignee: Jiangnan University
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2022-08-23
Anticipated expiration: 2041-11-30
Also published as: CN114147953A

Abstract

The invention discloses additive manufacturing equipment and a method based on material extrusion and photocuring composite molding, wherein the equipment comprises a plurality of molding modules, an extrusion pressure is provided by an air source, and a discharge port of a charging barrel is connected with an extrusion nozzle by a rotary two-way valve; on one hand, the slurry can be smoothly extruded without applying too large pressure in the charging barrel, on the other hand, the high-viscosity slurry can be extruded out through the small-diameter extrusion nozzle, and the control precision of the extrusion amount is high, so that the spatial high-precision distribution of multiple materials can be realized by accurately controlling the discrete distribution of the multiple materials, and the correct materials are realized at the correct positions. By adopting the annular ultraviolet projector provided by the invention, extruded slurry can be cured in time, and the deformation of a workpiece is small; also, the extrusion process and the photo-curing process may be performed simultaneously.

Description

Additive manufacturing equipment and method based on material extrusion and photocuring composite molding

Technical Field

The invention relates to additive manufacturing equipment and method based on material extrusion and photocuring composite molding, and belongs to the technical field of additive manufacturing.

Background

The additive manufacturing has become widely applied in the manufacturing industry, and the application of the additive manufacturing technology to preparing structural and functional materials has extremely important significance in the industries of aerospace, medical use, integrated circuits and the like. The structural and functional materials prepared by the additive manufacturing technology have higher requirements on the material spatial resolution and compactness of the blank in the manufacturing process. The photo-polymerization PPM forming additive manufacturing process can meet the preparation requirement of a high-resolution blank, but the components of a precursor slurry pool cannot be changed in real time, so that a composite structure of multiple materials is difficult to prepare. Material Extrusion, MEX molding additive manufacturing process can prepare multi-Material composite structures, but the process is difficult to overcome the contradiction between the fluidity and the shape retention of the Extrusion slurry, i.e. if the solid phase component content of the Extrusion slurry is high, the viscosity of the slurry is high, the Extrusion is difficult, and if the solid phase component content of the Extrusion slurry is low, the Extrusion is easy, but the molded blank is easy to collapse and deform.

In order to be able to prepare multi-material composites efficiently and at low cost and to achieve high-precision spatial distribution of the materials, researchers have proposed some process improvements and device innovations. Most of the innovative schemes proposed at present combine two process methods of photocuring and material extrusion, but all have the problems of poor forming precision, easy mixed pollution among multiple materials, insufficient material proportion control precision, high requirement on forming materials, low forming efficiency, high equipment cost and the like, and the specific analysis is as follows.

Patent CN113059792A provides an online variable-component photocuring 3D printing device and method, including laser generation module, compounding feeding mechanism can extrude many material mixes, and laser generation module can carry out the selective solidification to the material of printing. But the shortcoming that this design exists lies in, and material mixing feeding mechanism takes place different materials easily and pollutes each other and produce the material and mix proportion control error, and the module takes place to the laser moreover and need remove material mixing feeding mechanism when the solidification, and the real-time and the efficiency of solidification are not high, and the cost of the module is also higher to the laser in addition.

Patent CN113320142A proposes a multi-material photocuring 3D printing apparatus, which includes a plurality of extrusion nozzles and a photocuring mechanism corresponding to a plurality of materials, wherein the plurality of extrusion nozzles can extrude different materials, and then the multi-material structural member can be obtained by projection curing photocuring through the photocuring mechanism. On the one hand, the apparatus still has the similar disadvantages as the apparatus of patent CN113059792A, namely, the light curing mechanism needs to remove the extrusion nozzle during curing, the real-time performance and efficiency of curing are not high, and the cost of the light curing mechanism is also high; on the other hand, the material extrusion of the scheme is driven by the rotary screw, and the material cylinder is connected with the spray head through the material conveying pipe, so that the scheme is difficult to extrude the slurry with higher viscosity, the start-stop control response of the extrusion is slow, and the accurate and rapid control of the extrusion amount is difficult to realize.

The patent CN112895441A proposes a 3D printing method for integrally manufacturing a continuous functionally graded material and a structure, which introduces a constrained sacrificial layer based on fused deposition modeling FDM to form a constrained support structure, and additionally adopts a passive hybrid printing nozzle to form a continuous functionally graded material structure. However, the scheme of the constrained sacrificial layer based on Fused Deposition Modeling (FDM) introduced by the design limits the material of the sacrificial layer, and the material can meet the requirements of the FDM process; the passive mixing printing nozzle still has the problems that mutual pollution of different materials is easy to occur and the control error of the material mixing ratio is large; in addition, the extrusion nozzle is connected with the feeding module through a pipeline, so that the problems that slurry with high viscosity is difficult to extrude, the start-stop control response of extrusion is slow, and the accurate and rapid control of the extrusion amount is difficult to realize exist.

Disclosure of Invention

In order to solve the existing problems, the invention provides additive manufacturing equipment and a method based on material extrusion and photocuring composite molding, and the technical scheme is as follows:

the invention firstly provides additive manufacturing equipment based on material extrusion and photocuring composite molding, which comprises: the device comprises a base, a three-axis motion platform, a main support, an extrusion control device, a forming device and a curing light source device; the three-axis motion platform and the main support are respectively arranged on the base and are respectively positioned at two sides of the base, the forming device and the extrusion control device are both arranged on the main support, the forming device is connected with the extrusion control device through a pipeline, and the forming device is positioned at one side close to the three-axis motion platform on the main support; the curing light source device is arranged on the support and is positioned on one side of the main bracket.

The three-axis motion platform is used for providing necessary relative motion between the extrusion nozzle and the workpiece platform in the additive manufacturing process; the main bracket is used for supporting the extrusion control device and the forming device; the forming device is used for extruding materials and solidifying materials; the extrusion control device is used for controlling the starting and stopping of the material extruded by the forming device; the curing light source device is used for providing curing light for a light curing process.

According to an aspect of the present invention, in one embodiment, the extrusion control apparatus includes: the device comprises a device bottom plate, a pressurization control module, an on-off control module and an air source; the device bottom plate is fixedly connected with the main bracket, and the pressurization control module and the on-off control module are respectively arranged on the device bottom plate; the pressurization control module is used for controlling an extrusion pressurization unit of the molding device; the on-off control module is used for controlling an extrusion on-off unit of the forming device; the air source is respectively connected with the pressurization control module and the on-off control module through a pipeline and a connecting piece.

According to an aspect of the present invention, the pressurization control module includes: a pressurizing confluence plate and a plurality of pressurizing control valves; the pressurizing bus bar is arranged on a device bottom plate of the extrusion control device, an air inlet and an air outlet are arranged on one side of the pressurizing bus bar, and the air inlet is connected with an air source through an air inlet connecting piece; the exhaust port is provided with an exhaust silencer; the plurality of pressure control valves are arranged on the pressure collecting plate, the number of the pressure control valves is the same as that of the forming modules in the forming device, the pressure control valves are respectively connected with the corresponding forming modules, and the pressure control valves are two-position three-way electromagnetic control valves.

According to the technical scheme of the invention, in one embodiment, an air outlet of the pressure control valve is connected with an air inlet of a cylinder of an extrusion pressurizing unit on a corresponding forming module through a pipeline and a pipeline connecting piece; and the air inlet of the pressurizing control valve is connected with the air inlet on the pressurizing bus plate, and the air outlet of the pressurizing control valve is connected with the air outlet on the pressurizing bus plate.

According to the technical solution of the present invention, in one embodiment, the on-off control module includes: the on-off confluence plate and the on-off control valves are arranged on the upper surface of the cylinder; the on-off bus bar is arranged on a device bottom plate of the extrusion control device, an air inlet and an air outlet are arranged on one side of the on-off bus bar, and the air inlet is connected with an air source through an air inlet connecting piece; the exhaust port is provided with an exhaust silencer; the on-off control valves are installed on the on-off confluence plate, the number of the on-off control valves is the same as that of the forming modules in the forming device, the on-off control valves are respectively connected with the corresponding forming modules, and the on-off control valves are electromagnetic control middle position closed type three-position five-way valves.

According to the technical scheme of the invention, in one implementation mode, an air outlet A of the on-off control valve is connected with an air inlet A of a rotary cylinder on a corresponding forming module through a pipeline and a connecting piece, and an air outlet B of the on-off control valve is connected with an air inlet B of the rotary cylinder on the corresponding forming module through a pipeline and a connecting piece; and the air inlet of the on-off control valve is connected with the air inlet on the on-off bus bar, and the air outlet of the on-off control valve is connected with the air outlet on the on-off bus bar.

According to the technical scheme of the invention, in one embodiment, the forming device comprises a module mounting bracket and a plurality of forming modules; the plurality of forming modules are fixedly connected with the module mounting bracket, and the module mounting bracket is fixedly connected to the main bracket; the molding module comprises a module bracket and an extrusion pressurizing unit, a charging barrel unit, an extrusion on-off unit and a photocuring unit which are sequentially arranged on the module bracket; a plurality of the forming modules can be used to form a plurality of the same or different materials.

According to the technical scheme of the invention, in one embodiment, the forming module is arranged in the die set; the extrusion pressurizing unit is a cylinder-piston unit and is fixedly connected to the module bracket through a fastener; the charging barrel unit comprises a charging barrel, a piston and a charging barrel pressing cover plate; the barrel pressing cover plate is positioned at the upper part of the barrel, and the barrel is fixedly connected to the module bracket through the barrel pressing cover plate and a fastening piece; the piston is arranged in the material cylinder and is connected with the piston of the extrusion pressurizing unit, and a discharge hole is formed in the lower part of the material cylinder; the extrusion on-off unit comprises a module support plate, a rotary cylinder, a rotary valve coupler, a rotary two-way valve and an extrusion nozzle; the module support plate is fixed on the module support, and the rotary cylinder is fixed on the module support plate; one end of the rotary two-way valve is connected with the discharge hole of the charging barrel, and the other end of the rotary two-way valve is connected with the extrusion nozzle; one end of the rotary valve coupler is connected with an output shaft of the rotary cylinder, the other end of the rotary valve coupler is connected with a knob of the rotary two-way valve, and the rotary cylinder can control the on-off of the rotary two-way valve through the rotary valve coupler.

According to the technical scheme of the invention, in one embodiment, the light curing unit comprises an annular ultraviolet light projector and a light emitting optical fiber, the annular ultraviolet light projector is fixedly connected to the module bracket, the annular ultraviolet light projector is provided with an annular groove structure, and the light emitting optical fiber is fixed in the annular groove structure of the annular ultraviolet light projector.

According to the technical scheme of the invention, in one embodiment, the curing light source device comprises a plurality of ultraviolet light generators, and the ultraviolet light generators are connected with the light emitting optical fibers in the annular ultraviolet light projectors of the corresponding molding modules through light guide optical fibers.

According to the technical scheme of the invention, based on the additive manufacturing equipment based on material extrusion and photocuring composite molding, the additive manufacturing technology meeting the requirement of high-precision distribution of multiple materials can be realized according to the following manufacturing method.

The invention further provides an additive manufacturing method based on material extrusion and photocuring composite molding, which adopts the equipment provided by the invention and comprises the following steps:

the method comprises the following steps: preparing slurry, namely preparing different materials to be molded into slurry, and adding a photoinitiator into one or more of the slurry to enable the slurry to be cured by ultraviolet light;

step two: selecting the number of molding modules according to the type of the material, and configuring a pressurization control module and an on-off control module in the corresponding extrusion control device according to the number of the molding modules;

step three: determining the number of ultraviolet light generators of a curing light source device according to the number of the slurry to be cured, enabling the light wave wavelength of the ultraviolet light generators to be consistent with the sensitive wavelength of a photoinitiator in the slurry, and connecting the ultraviolet light generators with corresponding light emitting optical fibers in the molding module by using light guide optical fibers;

step four: filling slurry and installing molding modules, respectively filling the slurry of different materials into the material cylinders of the corresponding molding modules, installing the material cylinders to the molding module bracket, and installing a plurality of molding modules to the module mounting bracket after the installation of other units of the molding modules is finished;

step five: initializing equipment, testing the functions of the corresponding forming modules by controlling a plurality of pressure control valves and a plurality of on-off control valves of the pressure control module and the on-off control module, and returning the triaxial movement platform to a zero position;

step six: carrying out slicing and layering processing on a digital model of a part to be molded to obtain printing paths of different sizing agents, optimizing control instructions of all the printing paths, and preferentially using light-curable sizing agents to print peripheral parts of the part to obtain better shape retentivity;

step seven: the equipment starts to form according to a control instruction, and when each layer is formed, 1-2 layers of the periphery of the part are extruded and cured preferentially to form a frame structure which is not easy to deform;

step eight: and finishing forming, and taking down the workpiece from the three-axis motion platform.

According to the technical scheme of the invention, the principle of the slurry extrusion process of the forming device of the equipment is as follows:

when a certain forming module needs to extrude slurry, the pressure control valve corresponding to the forming module is switched into: compressed air is led into a cylinder of an extrusion pressurizing unit of the forming module, after a certain time delay, slurry in the charging barrel meets the requirement of extrusion pressure, an air outlet A of a corresponding on-off control valve is immediately controlled to be conducted, so that a rotary cylinder of the forming module rotates and drives a rotary two-way valve to be conducted, and the slurry is extruded; when a certain forming module needs to stop extruding the slurry, the pressure control valve corresponding to the forming module is switched to: and the air cylinder of the extrusion pressurizing unit of the forming module enters an exhaust state, high-pressure gas in the air cylinder of the extrusion pressurizing unit of the forming module is exhausted, so that the pressure of the slurry in the charging barrel is relieved, and the air outlet B of the corresponding on-off control valve is controlled to be communicated, so that the rotating air cylinder of the forming device rotates in the reverse direction and drives the rotating two-way valve to be closed, and the extrusion of the slurry is stopped.

According to the technical scheme of the invention, the principle of the photocuring process of the forming device of the equipment is as follows:

after the slurry is extruded from the forming module, if a certain slurry is prepared into the curable slurry containing the photoinitiator and the structure of the slurry forming position in the part to be formed needs to be reinforced, the power supply of the corresponding ultraviolet light generator is turned on when the slurry is extruded, and the ultraviolet light generator in the forming module is arranged in an annular shape, so that the ultraviolet light corresponding to the slurry is in annular projection by taking an extruding point as the center of a circle, and the extruded slurry can be cured no matter which direction the platform moves.

According to the technical scheme of the invention, when the digital model of the part to be molded is sliced and layered, the extrusion control, the photocuring process and the movement set of the three-axis platform are compiled into a control instruction sequence for the independent work of equipment.

The invention has the beneficial effects that:

by adopting the additive manufacturing equipment and method based on material extrusion and photocuring composite molding, the efficient manufacturing of the multi-material structure blank can be realized, and the following beneficial effects are realized.

Firstly, realizing the spatial high-precision distribution of multiple materials; according to the design of the plurality of forming modules, the air source provides extrusion pressure, the discharge port of the charging barrel is connected with the extrusion nozzle through the rotary two-way valve, and the near-end extrusion mode can reduce pressure loss and extrusion start-stop time delay caused by long-distance transmission of slurry in a pipeline due to viscoelasticity of the slurry; on one hand, the slurry can be smoothly extruded without applying too large pressure in the charging barrel, on the other hand, the situation that if the charging barrel is pressurized, but the slurry is not extruded from the spray head at a later time or the spray head is still extruding the slurry after the charging barrel is decompressed is avoided, so that the high-viscosity slurry can be extruded out through the small-diameter extrusion spray head, the start and stop of the extrusion are controlled by the rotary two-way valve, the control precision of the extrusion amount is high, the discrete distribution of multiple materials can be accurately controlled, the spatial high-precision distribution of the multiple materials is realized, and the correct materials are in correct positions.

Secondly, the real-time performance and controllability of photocuring are higher, and the forming effect is better; the annular ultraviolet light projector provided by the invention can finish curing of extruded slurry in time, the deformation of a workpiece is small, the light intensity is more uniformly distributed in all directions, and the process consistency is better; in addition, the light intensity and the extrusion speed of the light curing process are controlled, the curing process can be adjusted in a wider range, and the process adaptability is better.

Thirdly, the requirement on materials is low, and the universality is better; the method has better adaptability to the slurry with different rheological properties and different viscosities, and can realize smooth extrusion by increasing the pressure of an air source, replacing a large-diameter extrusion cylinder and other methods for the slurry with high viscosity; for low viscosity and easy deformation slurry, a photoinitiator can be added to carry out real-time curing, or the photoinitiator can be added to other slurry to form peripheral support and then the low viscosity slurry is extruded.

Fourthly, the process efficiency is high, and the equipment economy is high; by adopting the equipment and the method provided by the invention, the extrusion process and the photocuring process can be simultaneously carried out, and the forming efficiency is greatly improved. In addition, the equipment provided by the invention adopts universal standardized components, so that the components are easy to obtain, and the overall economy is high.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of the general structure of the apparatus of the present invention;

FIG. 2 is a schematic view of the general structure of an extrusion control apparatus in the apparatus of the present invention;

FIG. 3 is a schematic overall view of a forming device in the apparatus of the present invention;

FIG. 4 is a schematic diagram of a first forming module of the forming apparatus of the present invention;

FIG. 5 is a schematic diagram of the structure of a light-curing unit in a molding device in the apparatus of the present invention;

FIG. 6 shows the solidification of the material in the forming device in different extrusion movement directions in the apparatus of the present invention;

wherein, 1-a base; 2-a three-axis motion platform; 3-main support, 4-extrusion control device; 5-a forming device; 6-curing unit light source device.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The first embodiment is as follows:

the embodiment provides an additive manufacturing device based on material extrusion and photocuring composite molding, and the overall structure of the device of the embodiment is shown in fig. 1. The apparatus provided by this embodiment may enable additive manufacturing of a minimum of three different materials.

Referring to fig. 1, the apparatus comprises: the device comprises a base 1, a three-axis motion platform 2, a main support 3, an extrusion control device 4, a forming device 5 and a curing light source device 6. Wherein, the three-axis motion platform 2 and the main support 3 are respectively arranged on the base 1 and are respectively positioned at two sides of the base 1. The forming device 5 and the extrusion control device 4 are both arranged on the main support 3, the forming device 5 is connected with the extrusion control device 4 through a pipeline, and the forming device 5 is positioned on one side of the main support 3 close to the three-axis motion platform 2; the curing light source device 6 is arranged on the support 1 and is positioned at one side of the main bracket 3. The three-axis motion platform is used for providing necessary relative motion between the extrusion nozzle and the workpiece platform in the additive manufacturing process; the main support 3 is used for supporting the extrusion control device 4 and the molding device 5; the forming device 5 is used for extruding materials and solidifying materials; the extrusion control device 4 is used for controlling the start and stop of the material extruded by the forming device 5; the curing light source device 6 is used for providing curing light for the light curing process.

As an example, in the apparatus of the present embodiment, the molding modules in the molding device 5 are three sets, and the corresponding extrusion control device 4 is provided with three sets of pressure control valves and three sets of on-off control valves in the pressure control module 42 and the on-off control module 43, respectively. It should be understood that embodiments of the present invention are not limited to three materials, and multiple sets of modules may be designed to perform molding of multiple identical or different materials.

In one embodiment, the extrusion control device 4 is schematically shown in fig. 2, and the extrusion control device 4 includes a device bottom plate 41, a pressurization control module 42, an on-off control module 43, an air source 44, an air inlet pipe 45 and a connecting pipeline. The pressurizing control module 42 and the on-off control module 43 are mounted on the apparatus base plate 41.

In one embodiment, the device base plate 41 of the extrusion control device 4 is fixedly connected with the main support 3; the pressurization control module 42 is used for controlling an extrusion pressurization unit in a molding module of the molding device 5; the on-off control module 43 is used for controlling an extrusion on-off unit in a forming module of the forming device 5; the air source 44 is connected with the pressurization control module 42 and the on-off control module 43 through pipelines and connecting pieces respectively.

As shown in fig. 2, the pressurization control module 42 includes a pressurization manifold plate 420, a pressurization manifold plate intake connection 42P, a pressurization manifold plate exhaust muffler 42R, and a plurality of pressurization control valves provided on the pressurization manifold plate 420, including: the first pressure control valve 421, the second pressure control valve 422, the third pressure control valve 423, the

pressure control valves

421, 422, 423 are respectively provided with corresponding

pipeline connecting pieces

421A, 422A, 423A. The pressurizing manifold plate 420 is installed on the device base plate 41, and the pressurizing manifold plate air inlet connecting piece 42P and the pressurizing manifold plate exhaust silencer 42R are respectively arranged on the air inlet and the air outlet on one side of the pressurizing manifold plate 420, and are respectively connected to a pipeline to connect an air source and exhaust.

In one embodiment, three pressure control valves are configured to correspond to three different materials, respectively, and the air outlets of the first pressure control valve 421, the second pressure control valve 422 and the third pressure control valve 423 are connected to the air inlets of the cylinders of the extrusion and pressurization units on the corresponding first to third molding modules through pipeline connectors, respectively; for example, the pipe connection 421A of the first pressure control valve 421 is connected to the extrusion cylinder intake port connection 512P (shown in fig. 4) in the first molding group 51; also, the inlet port of each pressure control valve is connected to the inlet port on the pressurization manifold plate 420, and the outlet port of each pressure control valve is connected to the outlet port on the pressurization manifold plate 420. The three pressure control valves are two-position three-way electromagnetic control valves.

In one embodiment, as shown in fig. 2, the on-off control module 43 includes an on-off manifold 430, an on-off manifold inlet connector 43P, an on-off manifold exhaust muffler 43R, a first on-off control valve 431, a second on-off control valve 432, and a third on-off control valve 433, wherein the gas outlets a of the first to third on-off

control valves

431, 432, and 433 are respectively provided with

corresponding pipeline connectors

431A, 432A, and 433A, and the gas outlets B of the first to third on-off

control valves

431, 432, and 433 are respectively provided with

corresponding pipeline connectors

431B, 432B, and 433B.

The on-off control module includes an on-off manifold 430 and a plurality of on-off control valves, and the on-off manifold 430 is mounted on the device base plate 41. The on-off manifold intake connector 43P and the on-off manifold exhaust silencer 43R are respectively disposed on the intake port and the exhaust port on one side of the on-off manifold 430, and are respectively connectable to a pipeline to connect an air source and exhaust.

In one embodiment, the first to third on-off

control valves

431, 432 and 433 are configured to be respectively disposed corresponding to three different materials and three molding modules, and the air outlet a of each on-off control valve is respectively connected to the pipeline connector of the air inlet a of the rotary cylinder corresponding to the first to third molding modules through the

respective pipeline connectors

431A, 432A and 433A and the pipeline; and the air outlet B of each on-off control valve is respectively connected with the air inlet B of the rotary cylinder on the corresponding first forming module to the third forming module through

pipeline connecting pieces

431B, 432B and 433B and pipelines. For example, the pipe connection 431A of the first on-off control valve 431 is connected to the rotary cylinder intake port a pipe connection 5145A of the first molding group 51, and the pipe connection 431B is connected to the rotary cylinder intake port B pipe connection 5145B of the first molding group 51, as shown in fig. 4. The first to third on-off control valves are all electromagnetic control middle position closed type three-position five-way valves.

In one embodiment, the air source 44 is a pressure-stabilized air source with dehumidification and dust filtration functions, and may be an industrial air compressor, and the air source 44 is connected to the pressurization manifold intake connector 42P and the on-off manifold intake connector 43P through the intake pipes 45.

In one embodiment, the forming device 5 is configured as shown in FIG. 3; forming device 5 includes module installing support 50 and three shaping module: a first molding group 51, a second molding group 52, and a third molding group 53; each of the molding modules is fixedly connected to the module mounting bracket 50. The first molding group 51, the second molding group 52, and the third molding group 53 have the same main structure. The module mounting bracket 50 is fixedly connected to the main bracket 3; each molding module comprises a module bracket and an extrusion pressurizing unit, a charging barrel unit, an extrusion on-off unit and a photocuring unit which are sequentially arranged on the module bracket; a plurality of the forming modules can be used to form a plurality of the same or different materials.

In one embodiment, the first molding die set 51 is constructed as shown in fig. 4. Referring to fig. 4, the first molding die set 51 includes a die set holder 511, and an extrusion pressing unit 512, a cartridge unit 513, an extrusion on-off unit 514, and a photo-curing unit 515, which are sequentially mounted thereon.

Referring to fig. 4, the first forming die set 51; the extrusion pressurizing unit 512 is a cylinder-piston unit, and is fixedly connected to the module bracket 511 by a fastener, and specifically includes: an extrusion cylinder barrel 5121, an extrusion cylinder piston 5122, an extrusion cylinder lock nut 5123, an extrusion cylinder air inlet connector 512P and an extrusion cylinder air outlet connector 512R. The extrusion cylinder barrel 5121 is fixed on the module bracket 511 by an extrusion cylinder lock nut 5123, and the extrusion cylinder air inlet connecting piece 512P and the extrusion cylinder air outlet connecting piece 512R are installed on the extrusion cylinder barrel 5121.

The cartridge unit 513 includes a cartridge, a piston, and a cartridge pressing cover plate. As shown in fig. 4, the cartridge unit 513 specifically includes: a charging barrel 5131, a piston 5132, a connecting nut 5133, a charging barrel pressing cover plate 5134, a charging barrel pressing cover plate locking bolt 5135 and a charging barrel discharging port locking nut 5136. The cartridge 5131 is fixed to the module bracket 511 by a cartridge compression cover plate 5134 and a cartridge compression cover plate locking bolt 5135. The piston 5132 is installed in the cartridge 5131 and is coupled with the extrusion cylinder piston 5122 by a coupling nut 5133.

In one embodiment, the cartridge compression cover 5134 is located at the upper portion of the cartridge 5131, and the cartridge 5131 is fixedly connected to the module bracket 511 by the cartridge compression cover 5134 and the above-mentioned fasteners; the piston 5132 is arranged in the cylinder and connected with the extrusion cylinder piston 5122 of the extrusion pressurizing unit 512, and the lower part of the cylinder is provided with a discharge hole.

In one embodiment, the extrusion on-off unit includes a module plate 5141, a module plate fixing bolt 5142, a rotary cylinder 5143, a rotary cylinder fixing bolt 5144, a rotary cylinder air inlet a pipeline connector 5145A, a rotary cylinder air inlet B pipeline connector 5145B, a rotary valve coupler 5146, a rotary two-way valve 5147, and an extrusion nozzle 5148. The module support plate 5141 is fixed on the module support 511 through a module support plate fixing bolt 5142, the rotary cylinder 5143 is fixed on the module support plate 5141 through a rotary cylinder fixing bolt 5144, one end of the rotary two-way valve 5147 is connected with the feed cylinder discharge port locking nut 5136, the other end of the rotary two-way valve 5147 is connected with the extrusion spray head 5148, one end of the rotary valve coupling 5146 is connected with the output shaft of the rotary cylinder 5143, the other end of the rotary valve coupling 5147 is connected with a knob of the rotary two-way valve 5147, and the rotary cylinder 5143 controls the on-off of the rotary two-way valve 5147 through the rotary valve coupling 5146.

In one embodiment, the light curing unit 515 is constructed as shown in fig. 4-5, and the light curing unit 515 includes a ring-shaped uv projector 5151, a light emitting optical fiber 5152, and a ring-shaped uv projector fixing bolt 5153. The annular ultraviolet light projector 5151 is fixed on the module bracket 511 by an annular ultraviolet light projector fixing bolt 5153, and the light emitting optical fiber 5152 is installed in the annular ultraviolet light projector 5151. Referring to fig. 5, the annular ultraviolet light projector 5151 has an annular groove structure, and the light emitting optical fiber 5152 is fixed in the annular groove structure of the annular ultraviolet light projector.

In one embodiment, FIG. 6 shows the solidification of a material in a forming apparatus 5 according to the present invention in different directions of extrusion movement; in which the extrusion head 5148 moves in different moving directions, such as the moving direction a and the moving direction B shown in fig. 6, and the extruded material intersects with the annular curing light projection area formed by the curing light projected from the light curing unit 515, thereby generating a curing effect.

In one embodiment, the curing light source device 6 includes a plurality of uv light generators connected to the light emitting fibers 5152 of the ring-shaped uv light projector 5151 of the corresponding molding module via light guiding fibers.

Based on the additive manufacturing equipment based on material extrusion and photocuring composite molding, additive manufacturing technology meeting high-precision distribution of multiple materials can be realized according to the following manufacturing method.

Example two

The embodiment provides an additive manufacturing method based on material extrusion and photocuring composite molding, which adopts the equipment according to the first embodiment, and comprises the following steps:

step six: carrying out slicing and layering processing on a digital model of a part to be molded to obtain printing paths of different sizing agents, optimizing control instructions of all the printing paths, and preferentially printing peripheral parts of the part by using the light-curable sizing agent to obtain better shape retentivity;

According to the technical scheme of the embodiment, the principle of the slurry extrusion process of the forming device of the equipment is as follows:

when a certain forming module needs to extrude slurry, the pressure control valve corresponding to the forming module is switched into: compressed air is led into an air cylinder of an extrusion pressurizing unit of the forming module, after a certain time delay, slurry in the charging barrel meets the extrusion pressure requirement, an air outlet A of a corresponding on-off control valve is immediately controlled to be conducted, a rotary air cylinder of the forming module rotates and drives a rotary two-way valve to be conducted, and the slurry is extruded; when a certain forming module needs to stop extruding the slurry, the pressure control valve corresponding to the forming module is switched to: and the air cylinder of the extrusion pressurizing unit of the forming module enters an exhaust state, high-pressure gas in the air cylinder of the extrusion pressurizing unit of the forming module is exhausted, so that the pressure of the slurry in the charging barrel is relieved, and the air outlet B of the corresponding on-off control valve is controlled to be communicated, so that the rotating air cylinder of the forming device rotates in the reverse direction and drives the rotating two-way valve to be closed, and the extrusion of the slurry is stopped.

According to the technical scheme of the embodiment, the principle of the photocuring process of the forming device of the equipment is as follows:

after the slurry is extruded from the forming module, if a certain slurry is prepared into the curable slurry containing the photoinitiator and the structure of the slurry forming position in the part to be formed needs to be reinforced, the power supply of the corresponding ultraviolet light generator is turned on when the slurry is extruded.

Some steps in the embodiments of the present invention may be implemented by software, and the corresponding software program may be stored in a readable storage medium, such as an optical disc or a hard disk.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. Additive manufacturing device based on material extrusion and photocuring composite forming, characterized in that the device comprises: the device comprises a base, a three-axis motion platform, a main support, an extrusion control device, a forming device and a curing light source device;

the three-axis motion platform and the main support are respectively arranged on the base and are respectively positioned at two sides of the base, the forming device and the extrusion control device are both arranged on the main support, the forming device is connected with the extrusion control device through a pipeline, and the forming device is positioned at one side close to the three-axis motion platform on the main support; the curing light source device is arranged on the base and is positioned on one side of the main bracket;

the three-axis motion platform is used for providing necessary relative motion between the extrusion nozzle and the workpiece platform in the additive manufacturing process; the main bracket is used for supporting the extrusion control device and the forming device; the forming device is used for extruding materials and solidifying materials; the extrusion control device is used for controlling the start and stop of the material extruded by the forming device; the curing light source device is used for providing curing light for the light curing process;

the extrusion control device includes: the device comprises a device bottom plate, a pressurization control module, an on-off control module and an air source;

the device bottom plate is fixedly connected with the main bracket, and the pressurization control module and the on-off control module are respectively arranged on the device bottom plate; the pressurization control module is used for controlling an extrusion pressurization unit of the molding device; the on-off control module is used for controlling an extrusion on-off unit of the forming device;

the air source is respectively connected with the pressurization control module and the on-off control module through a pipeline and a connecting piece;

the pressurization control module includes: a pressurizing confluence plate and a plurality of pressurizing control valves;

the pressurizing bus bar is arranged on a device bottom plate of the extrusion control device, an air inlet and an air outlet are arranged on one side of the pressurizing bus bar, and the air inlet is connected with an air source through an air inlet connecting piece; the exhaust port is provided with an exhaust silencer;

the plurality of pressure control valves are arranged on the pressure collecting plate, the number of the pressure control valves is the same as that of the forming modules in the forming device, the pressure control valves are respectively connected with the corresponding forming modules, and the pressure control valves are two-position three-way electromagnetic control valves.

2. The apparatus according to claim 1, wherein the air outlet of the pressure control valve is connected with the air inlet of the air cylinder of the extrusion pressurizing unit on the corresponding forming die set through a pipeline and a pipeline connecting piece;

and the air inlet of the pressurizing control valve is connected with the air inlet on the pressurizing bus plate, and the air outlet of the pressurizing control valve is connected with the air outlet on the pressurizing bus plate.

3. The apparatus of claim 2, wherein the on-off control module comprises: the on-off confluence plate and a plurality of on-off control valves;

the on-off bus bar is arranged on a device bottom plate of the extrusion control device, an air inlet and an air outlet are arranged on one side of the on-off bus bar, and the air inlet is connected with an air source through an air inlet connecting piece; the exhaust port is provided with an exhaust silencer;

the on-off control valves are installed on the on-off confluence plate, the number of the on-off control valves is the same as that of the forming modules in the forming device, the on-off control valves are respectively connected with the corresponding forming modules, and the on-off control valves are electromagnetic control middle position closed type three-position five-way valves.

4. The equipment according to claim 3, wherein the air outlet A of the on-off control valve is connected with the air inlet A of the rotary air cylinder on the corresponding forming module through a pipeline and a connecting piece, and the air outlet B of the on-off control valve is connected with the air inlet B of the rotary air cylinder on the corresponding forming module through a pipeline and a connecting piece;

and the air inlet of the on-off control valve is connected with the air inlet on the on-off bus bar, and the air outlet of the on-off control valve is connected with the air outlet on the on-off bus bar.

5. The apparatus of claim 1, wherein the molding device comprises a plurality of molding modules and a module mounting bracket;

the plurality of forming modules are fixedly connected with the module mounting bracket, and the module mounting bracket is fixedly connected to the main bracket;

each molding module comprises a module bracket and an extrusion pressurizing unit, a charging barrel unit, an extrusion on-off unit and a photocuring unit which are sequentially arranged on the module bracket; a plurality of the forming modules can be used to form a plurality of the same or different materials.

6. The apparatus according to claim 5, characterized in that in each forming die set;

the extrusion pressurizing unit is a cylinder-piston unit and is fixedly connected to the module bracket by a fastener;

the charging barrel unit comprises a charging barrel, a piston and a charging barrel pressing cover plate; the barrel pressing cover plate is positioned at the upper part of the barrel, and the barrel is fixedly connected to the module bracket through the barrel pressing cover plate and a fastener; the piston is arranged in the material cylinder and is connected with the piston of the extrusion pressurizing unit, and a discharge hole is formed in the lower part of the material cylinder;

the extrusion on-off unit comprises a module support plate, a rotary cylinder, a rotary valve coupler, a rotary two-way valve and an extrusion nozzle; the module support plate is fixed on the module support, and the rotary cylinder is fixed on the module support plate; one end of the rotary two-way valve is connected with the discharge hole of the charging barrel, the other end of the rotary two-way valve is connected with the extrusion nozzle, one end of the rotary valve coupler is connected with an output shaft of the rotary cylinder, the other end of the rotary valve coupler is connected with a knob of the rotary two-way valve, and the rotary cylinder can control the on-off of the rotary two-way valve through the rotary valve coupler;

the light curing unit comprises an annular ultraviolet light projector and a light emitting optical fiber, the annular ultraviolet light projector is fixedly connected to the module support, the annular ultraviolet light projector is provided with an annular groove structure, and the light emitting optical fiber is fixed in the annular groove structure of the annular ultraviolet light projector.

7. The apparatus of claim 1, wherein the curing light source device comprises a plurality of uv light generators connected to the light emitting fibers in the ring-shaped uv light projectors of the corresponding molding modules by light guiding fibers.

8. Additive manufacturing method based on material extrusion and light curing composite moulding, characterized in that the method is applied to the apparatus according to any of claims 1-7, the method comprising the steps of:

step three: determining the number of ultraviolet light generators in a curing light source device according to the number of the sizing agent to be cured, enabling the light wave wavelength of the ultraviolet light generators to be consistent with the sensitive wavelength of a photoinitiator in the sizing agent, and connecting the ultraviolet light generators with corresponding light emitting optical fibers in the molding module by using light guide optical fibers;

step four: filling slurry and installing forming modules, respectively filling the slurry of different materials into the material cylinders of the corresponding forming modules, installing the material cylinders to a forming module bracket, and installing a plurality of forming modules to a module installing bracket after the installation of other units of the forming modules is finished;

step five: initializing equipment, testing the function of a corresponding forming module by controlling a plurality of pressure control valves and a plurality of on-off control valves in the pressure control module and the on-off control module, and returning the triaxial movement platform to a zero position;

step six: carrying out slicing and layering processing on a digital model of a part to be molded to obtain printing paths of different sizing agents, optimizing control instructions of the printing paths, and printing peripheral parts of the part by using light-curable sizing agents to obtain better shape retentivity;

step seven: the equipment starts to form according to the control instruction, and when each layer is formed, 1-2 layers of the periphery of the part are extruded and solidified to form a frame structure which is not easy to deform;