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

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 light curing composite molding

technical field

The invention relates to an additive manufacturing device and method based on material extrusion and light-curing composite molding, and belongs to the technical field of additive manufacturing.

Background technique

The application of additive manufacturing in the manufacturing industry has become more and more extensive. The application of additive manufacturing technology to prepare structural and functional materials is of great significance to the aerospace, medical, integrated circuit and other industries. The application of additive manufacturing technology to prepare structural and functional materials has high requirements on the material spatial resolution and compactness of the green body during the manufacturing process. The photo-curing photo-polymerization, PPM molding additive manufacturing process can meet the preparation requirements of high-resolution blanks, but the composition of the precursor slurry pool cannot be changed in real time, and it is difficult to make a composite structure of multiple materials. Material Extrusion Material Extrusion, MEX molding additive manufacturing process can prepare multi-material composite structures, but this process is difficult to overcome the contradiction between the fluidity and shape retention of the extrusion slurry, that is, if the solid phase of the extrusion slurry is used If the content of the slurry is high, the viscosity of the slurry will be high, and extrusion will be difficult. If the content of the solid phase component of the extruded slurry is low, it is easy to extrude, but the formed blank is prone to collapse and deformation.

In order to efficiently and cost-effectively fabricate multi-material composites and achieve high-precision spatial distribution of materials, researchers have proposed some process improvements and device innovations. Most of the innovative solutions proposed at present are the combination of light curing and material extrusion, but they all have problems such as poor molding accuracy, easy mixing and contamination between multiple materials, insufficient material ratio control accuracy, high requirements for molding materials, and molding efficiency. The problems of low cost and high equipment cost are analyzed as follows.

Patent CN113059792A proposes an online variable-component light-curing 3D printing device and method, including a laser generating module, a material mixing and feeding mechanism, the material mixing and feeding mechanism can mix and extrude multiple materials, and the laser generation module can selectively solidify the printed materials . However, the disadvantage of this design is that the mixing and feeding mechanism is prone to mutual contamination of different materials and the control error of material mixing ratio, and the laser generation module needs to move the mixing and feeding mechanism away during curing, so the real-time and efficiency of curing is not high. , and the cost of the laser generating module is also high.

Patent CN113320142A proposes a multi-material photo-curing 3D printing equipment, including multiple extrusion nozzles and photo-curing mechanisms corresponding to various materials. Multi-material structural parts are available. However, on the one hand, this equipment still has the similar shortcomings as the device of patent CN113059792A, that is, the light curing mechanism needs to move the extrusion nozzle away 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 this scheme is driven by a rotating screw, and the barrel and the nozzle are connected by a feeding pipe. This scheme is difficult to extrude the slurry with high viscosity, and the start and stop control response of the extrusion is slow. , it is difficult to achieve precise and rapid control of the extrusion volume.

The patent CN112895441A proposes a 3D printing method for continuous functionally graded material and structural integration. The scheme is to introduce a constrained sacrificial layer based on fused deposition modeling FDM to form a constrained support structure, and use passive hybrid printing nozzles to form a continuous functionally graded material structure. However, the constrained sacrificial layer scheme based on fused deposition modeling (FDM) introduced in this design has restrictions on the material of the sacrificial layer, and the material must meet the requirements of the FDM process; and the passive hybrid printing nozzle is still prone to mutual contamination of different materials and material mixing ratio. The problem of large control error; in addition, the extrusion nozzle and the feeding module are connected by pipelines, it is also difficult to extrude the slurry with high viscosity, and the start and stop control response of the extrusion is slow, and it is difficult to realize the extrusion volume. A matter of precise and rapid control.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problems existing at present, the present invention provides an additive manufacturing equipment and method based on material extrusion and photocuring composite molding, and the technical solution is as follows:

The present invention first proposes an additive manufacturing equipment based on material extrusion and photocuring composite molding. The equipment includes: a base, a three-axis motion platform, a main support, an extrusion control device, a molding device, and a curing light source device; the three The axis motion platform and the main support are respectively arranged on the base and on both sides of the base, the forming device and the extrusion control device are both installed on the main support, and the forming device is connected to the main support. The extrusion control device is connected through a pipeline, and the forming device is located on the main support on the side close to the three-axis motion platform; the curing light source device is arranged on the support and located at the the side of the main bracket.

The three-axis motion platform is used to provide necessary relative motion between the extrusion nozzle and the workpiece platform during the additive manufacturing process; the main bracket is used to support the extrusion control device and the forming device; the forming device The role of the extrusion material is to extrude the material and the curing material; the extrusion control device is used to control the start and stop of the extrusion material of the molding device; the curing light source device is used to provide curing light for the light curing process.

According to the technical solution of the present invention, in one embodiment, the extrusion control device includes: a device bottom plate, a pressurization control module, an on-off control module and an air source; the device bottom plate is fixedly connected to the main support, The pressurization control module and the on-off control module are respectively arranged on the bottom plate of the device; the pressurization control module is used for controlling the extrusion pressurizing unit of the molding device; the on-off control module is used for The extrusion on-off unit of the molding device is controlled; the gas source is respectively connected with the pressurization control module and the on-off control module through pipelines and connecting pieces.

According to the technical solution of the present invention, the pressurization control module includes: a pressurization manifold and a plurality of pressurization control valves; the pressurization manifold is arranged on the device bottom plate of the extrusion control device, and the pressurization manifold One side of the pressure manifold is provided with an air inlet and an air outlet, and the air inlet is connected to an air source through an air inlet connector; the air outlet is provided with an exhaust muffler; a plurality of the pressurization control valves Set on the pressurization manifold, the number of the pressurization control valves is the same as the number of the molding modules in the molding device, and a plurality of the pressurization control valves are respectively connected with the corresponding molding modules, and the The pressure control valve is a two-position three-way electromagnetic control valve.

According to the technical solution of the present invention, in one embodiment, the air outlet of the pressurizing control valve is connected to the air cylinder air inlet of the extrusion pressurizing unit on the corresponding molding module through pipelines and pipeline connectors; The air inlet of the pressurization control valve is connected to the air inlet on the pressurization manifold, and the exhaust port of the pressurization control valve is connected to the air outlet on the pressurization manifold.

According to the technical solution of the present invention, in one embodiment, the on-off control module includes: on-off manifold and a plurality of on-off control valves; the on-off manifold is arranged on a device of the extrusion control device the bottom plate, and one side of the on-off manifold is provided with an air inlet and an air outlet, the air inlet is connected to the air source through an air inlet connector; the air outlet is provided with an exhaust muffler; Each of the on-off control valves is installed on the on-off manifold, the number of the on-off control valves is the same as the number of the molding modules in the molding device, and the plurality of on-off control valves are respectively associated with the corresponding The forming module is connected, and the on-off control valve is an electromagnetically controlled mid-position closed three-position five-way valve.

According to the technical solution of the present invention, in one embodiment, the air outlet A of the on-off control valve is connected to the air inlet A of the rotary cylinder on the corresponding molding module through pipelines and connectors, and the on-off control valve The air outlet B of the control valve is connected with the air inlet B of the rotary cylinder on the corresponding molding module through pipelines and connectors; the air inlet of the on-off control valve is connected to the air inlet on the on-off manifold plate. connected, and the exhaust port of the on-off control valve is connected to the exhaust port on the on-off manifold.

According to the technical solution of the present invention, in one embodiment, the molding device includes a module mounting bracket and a plurality of molding modules; a plurality of the molding modules are fixedly connected to the module mounting bracket, and the mold The group mounting bracket is fixedly connected to the main bracket; the forming module includes a module bracket and an extrusion pressurizing unit, a barrel unit, an extrusion on-off unit and a light curing unit 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 solution of the present invention, in one embodiment, in the forming module; the extrusion pressing unit is a cylinder-piston unit, and is fixedly connected to the module bracket by a fastener; The barrel unit includes a barrel, a piston and a barrel pressing cover; the barrel pressing cover is located on the upper part of the barrel, and the barrel is pressed and fastened by the barrel The part is fixedly connected to the module bracket; the piston is arranged in the barrel and is connected with the piston of the extrusion pressurizing unit, and the lower part of the barrel is provided with a discharge port; the extrusion through The breaking unit includes a module support plate, a rotating cylinder, a rotary valve coupling, a rotating two-way valve and an extrusion nozzle; the module support plate is fixed on the module bracket, and the rotating cylinder is fixed on the mold One end of the rotary two-way valve is connected to the discharge port of the barrel, and the other end is connected to the extrusion nozzle; one end of the rotary valve coupling is connected to the output shaft of the rotary cylinder, and the other end is connected to the output shaft of the rotary cylinder. One end is connected with the 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 coupling.

According to the technical solution of the present invention, in one embodiment, the light curing unit includes an annular ultraviolet light projector and a light-emitting optical fiber, the annular ultraviolet light projector is fixedly connected to the module bracket, and the annular ultraviolet light The projector has 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 solution of the present invention, in one embodiment, the curing light source device includes a plurality of ultraviolet light generators, and the ultraviolet light generators pass through the light guide fiber and the corresponding annular ultraviolet light projector of the molding module. the light-emitting fiber connection.

According to the technical solution of the present invention, based on the above-mentioned additive manufacturing equipment based on material extrusion and photocuring composite molding, according to the following manufacturing method, an additive manufacturing technology that satisfies the high-precision distribution of multiple materials can be realized.

The present invention further proposes an additive manufacturing method based on material extrusion and photocuring composite molding. The method adopts the equipment of the present invention, and the method includes the following steps:

Step 1: Slurry configuration, configure different materials to be molded into slurries, and add a photoinitiator to one or more of the slurries so that they can be cured by ultraviolet light;

Step 2: select the number of molding modules according to the type of material, and configure the corresponding pressurization control module and on-off control module in the extrusion control device according to the number of molding modules;

Step 3: Determine the number of ultraviolet light generators of the curing light source device according to the quantity of the paste to be cured, so that the light wave wavelength of the ultraviolet light generator is consistent with the sensitive wavelength of the photoinitiator in the paste, and connect it with a light guide fiber The ultraviolet light generator and the light-emitting fiber in the corresponding molding module;

Step 4: Fill the slurry and install the molding module, put the slurry of different materials into the barrel of the corresponding molding module, install the barrel to the molding module bracket, and install it in other units of the molding module. After the installation is completed, install multiple molding modules to the module mounting bracket;

Step 5: Equipment initialization, by controlling the pressurization control module and multiple pressurization control valves and multiple on-off control valves of the on-off control module, test the function of the corresponding molding module, and move the three-axis return the platform to zero;

Step 6: The digital model of the part to be formed is sliced and layered to obtain the printing paths of different pastes, and the control instructions of each printing path are optimized. Obtain better shape retention;

Step 7: The equipment starts to form according to the control instructions, and when forming each layer, it preferentially extrudes and solidifies 1-2 layers on the periphery of the part to form a frame structure that is not easily deformed;

Step 8: Complete the molding and remove the part from the three-axis motion platform.

According to the technical solution of the present invention, the principle of the slurry extrusion process of the molding device of the equipment is as follows:

When a molding module needs to extrude slurry, the pressurization control valve corresponding to the molding module is switched to: the cylinder of the extrusion pressurization unit of the molding module is fed with compressed air, and after a certain time delay, the cylinder is filled with compressed air. If the slurry reaches the extrusion pressure requirement, immediately control the outlet A of the corresponding on-off control valve to conduct, so that the rotary cylinder of the molding module rotates and drives the rotary two-way valve to conduct, and the slurry is extruded; When the molding module needs to stop extruding the slurry, the corresponding pressure control valve of the molding module is switched to: the cylinder of the extrusion pressurizing unit of the molding module enters the exhaust state, and the extrusion pressure of the molding module is pressed. The high-pressure gas in the cylinder of the unit is discharged to release the pressure of the slurry in the barrel, and the corresponding on-off control valve outlet B is controlled to conduct, so that the rotary cylinder of the molding device rotates in the opposite direction and drives the rotary two-way valve to close. Then the extrusion of the slurry was stopped.

According to the technical solution of the present invention, the principle of the light curing process of the molding device of the equipment is as follows:

After the slurry is extruded from the molding module, if a slurry has been configured as a curable slurry containing a photoinitiator, and the structure of the slurry in the part to be molded needs to be strengthened, When the material is extruded, turn on the power of the corresponding ultraviolet light generator. Since the ultraviolet light generator in the molding module is set in a ring, the ultraviolet light corresponding to the slurry is projected in a circle with the extrusion point as the center. In either direction, the extruded paste can be solidified.

According to the technical scheme of the present invention, when the digital model of the part to be formed is sliced and layered, the extrusion control, the light curing process and the motion set of the three-axis platform are compiled into a control command sequence for the equipment to work independently.

Beneficial effects of the present invention:

By adopting the additive manufacturing equipment and method based on material extrusion and photocuring composite molding proposed by the present invention, efficient manufacturing of multi-material structural blanks can be realized, and the following beneficial effects can be achieved.

1. Realize high-precision spatial distribution of multiple materials; the design of multiple molding modules proposed by the present invention provides extrusion pressure from the air source, and the outlet of the barrel and the extrusion nozzle are connected by a rotary two-way valve , this near-end extrusion method can reduce the pressure loss and extrusion start-stop delay caused by the viscoelasticity of the slurry caused by the long-distance transmission of the slurry in the pipeline; on the one hand, it is not necessary to apply too much pressure in the barrel The slurry can be extruded smoothly. On the other hand, it avoids the situation that the barrel is pressurized but the slurry is not extruded from the nozzle for a long time, or the barrel is released but the nozzle is still extruding the slurry. The viscosity slurry is extruded through a small diameter extrusion nozzle, and the start and stop of the extrusion is controlled by a rotary two-way valve. High precision distribution and achieve the right material in the right place.

Second, the real-time and controllability of light curing is higher, and the molding effect is better; and the annular ultraviolet light projector proposed by the present invention can complete the curing of the extruded slurry in time, the deformation of the workpiece is small, and the light The distribution of intensity in all directions is more uniform, and the process consistency is better; in addition, by controlling the light intensity and extrusion speed of the light curing process, the curing process can be adjusted in a wider range, and the process adaptability is better.

3. Low requirements for materials and better universality; better adaptability to slurries with different rheological properties and different viscosities. For high-viscosity slurries, it is possible to increase the air source pressure and replace the large-diameter extrusion. Smooth extrusion can be achieved by methods such as cylinders; for low-viscosity and easily deformable slurries, photoinitiators can be added to them for real-time curing, or photoinitiators can be added to other slurries to form peripheral support and then extrude the low-viscosity slurries. slurry.

Fourth, the efficiency of the process is high and the economy of the equipment is high; using the equipment and method proposed by the present invention, the extrusion process and the light curing process can be performed simultaneously, which greatly improves the molding efficiency. In addition, the equipment proposed by the present invention adopts general standardized components, the components are easy to obtain, and the overall economy is high.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

Fig. 1 is the overall structure schematic diagram of the equipment of the present invention;

2 is a schematic diagram of the overall structure of the extrusion control device in the equipment of the present invention;

Fig. 3 is the overall schematic diagram of the molding device in the equipment of the present invention;

4 is a schematic structural diagram of the first molding module in the molding device in the equipment of the present invention;

5 is a schematic structural diagram of a light curing unit in the molding device in the equipment of the present invention;

Figure 6 shows the solidification of the material in the molding device under different extrusion motion directions in the equipment of the present invention;

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

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

Example 1:

This embodiment provides an additive manufacturing device based on material extrusion and photocuring composite molding. The overall structure of the device in this embodiment is shown in FIG. 1 . The equipment provided in this embodiment can realize additive manufacturing of at least three different materials.

Referring to FIG. 1 , the equipment includes: a base 1 , a three-axis motion platform 2 , a main support 3 , an extrusion control device 4 , a molding device 5 and a curing light source device 6 . Wherein, the three-axis motion platform 2 and the main support 3 are respectively disposed on the base 1 and located on both sides of the base 1 respectively. Both the molding device 5 and the extrusion control device 4 are installed on the main support 3, the molding device 5 and the extrusion control device 4 are connected by pipelines, and the molding device 5 is located on the main support 3 close to the three-axis. One side of the moving platform 2 ; the curing light source device 6 is arranged on the support 1 and is located on one side of the main support 3 . The three-axis motion platform is used to provide necessary relative motion between the extrusion nozzle and the workpiece platform during the additive manufacturing process; the main bracket 3 is used to support the extrusion control device 4 and the forming device 5; The function of the molding device 5 is to extrude the material and the cured material; the extrusion control device 4 is used to control the start and stop of the extrusion material of the molding device 5; the curing light source device 6 is used to provide the light curing process. curing light.

As an example, in the apparatus of this embodiment, there are three groups of molding modules in the molding device 5 , and in the corresponding extrusion control device 4 , the pressure control module 42 and the on-off control module 43 are respectively Set up three groups of pressurized control valves and three groups of on-off control valves. It should be understood that the embodiments of the present invention are not limited to three materials, and a multi-component molding module can be designed to perform molding of multiple same or different materials.

In one embodiment, the schematic structure of the extrusion control device 4 is shown in FIG. 2 . The extrusion control device 4 includes a device bottom plate 41 , a pressurization control module 42 , an on-off control module 43 , and a gas source 44 . Intake pipe 45 and connecting pipeline. The pressurization control module 42 and the on-off control module 43 are mounted on the device base plate 41 .

In one embodiment, the device bottom plate 41 in the extrusion control device 4 is fixedly connected to the main bracket 3 ; the pressure control module 42 is used to control the molding module of the molding device 5 . The on-off control module 43 is used to control the extrusion on-off unit in the forming module of the forming device 5; the air source 44 is connected to the press The pressure control module 42 is connected to the on-off control module 43 .

As shown in FIG. 2 , the pressurization control module 42 includes a pressurization manifold 420 , a pressurized manifold intake connector 42P, a pressurized manifold exhaust muffler 42R, and a plurality of pressurized control valves are provided at the The pressure manifold 420 includes: a first pressure control valve 421, a second pressure control valve 422, and a third pressure control valve 423. The pressure control valves 421, 422, and 423 are respectively provided with corresponding Line connections 421A, 422A, 423A. The pressurized manifold 420 is installed on the device bottom plate 41 , and the pressurized manifold intake connector 42P and the pressurized manifold exhaust muffler 42R are respectively provided on the air inlet and the exhaust port on one side of the pressurized manifold 420 . , and respectively connect to the pipeline to connect the air source and exhaust.

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

In one embodiment, as shown in FIG. 2 , the on-off control module 43 includes on-off manifold 430 , on-off manifold inlet connector 43P, on-off manifold exhaust muffler 43R, first on-off manifold The control valve 431, the second on-off control valve 432, the third on-off control valve 433, and the air outlets A of the first to third on-off control valves 431, 432, 433 are respectively provided with corresponding pipeline connectors 431A, 432A, 433A, the air outlets B of the first to third on-off control valves 431, 432, 433 are respectively provided with corresponding pipeline connectors 431B, 432B, 433B.

The on-off control module includes a on-off manifold 430 and a plurality of on-off control valves, and the on-off manifold 430 is installed on the device bottom plate 41 . The on-off manifold inlet connector 43P and the on-off manifold exhaust muffler 43R are respectively disposed on the air inlet and exhaust port on one side of the on-off manifold 430, and can be connected to pipelines to connect the air source and the exhaust respectively. gas.

In one embodiment, the first to third on-off control valves 431 , 432 , and 433 are configured to correspond to three different materials and three molding modules, respectively, and the output of each on-off control valve is The air port A is connected to the air inlet A of the rotary cylinder corresponding to the first to third molding modules through the respective pipeline connectors 431A, 432A, 433A and pipelines respectively; the outlet of each on-off control valve is connected. The air port B is connected to the air inlet B corresponding to the rotary cylinders on the first to third forming modules respectively through the pipeline connectors 431B, 432B, 433B and pipelines. For example, the pipeline connector 431A of the first on-off control valve 431 is connected to the pipeline connector 5145A of the rotary cylinder air inlet A of the first molding module 51 , and the pipeline connector 431B is connected to the rotation of the first molding module 51 . Cylinder intake B line connection 5145B is connected as shown in FIG. 4 . The first to third on-off control valves are all electromagnetically controlled mid-position closed three-position five-way valves.

In one embodiment, the air source 44 is a regulated air source with dehumidification and dust filtering functions, and an industrial air compressor can be selected. The manifold intake connections 43P are connected.

In one embodiment, the structure of the forming device 5 is shown in FIG. 3 ; the forming device 5 includes a module mounting bracket 50 and three forming modules: a first forming module 51 and a second forming module 52 , the third molding module 53 ; each of the molding modules is fixedly connected to the module mounting bracket 50 . The main structures of the first forming module 51 , the second forming module 52 and the third forming module 53 are the same. The module mounting bracket 50 is fixedly connected to the main bracket 3; each of the molding modules includes a module bracket and an extrusion pressurizing unit, a barrel unit, an extrusion press unit, a barrel unit, and an extrusion press unit, which are sequentially arranged on the module bracket. On-off unit and light curing unit; a plurality of the molding modules can be used for molding a variety of the same or different materials.

In one embodiment, the structure of the first forming module 51 is shown in FIG. 4 . Referring to FIG. 4 , the first molding module 51 includes a module bracket 511 and an extrusion pressing unit 512 , a barrel unit 513 , an extrusion switching unit 514 , and a light curing unit 515 , which are sequentially installed thereon.

Referring to Figure 4, in the first molding module 51; the extrusion pressurizing unit 512 is a cylinder-piston unit, and is fixedly connected to the module bracket 511 by fasteners, specifically including: Extrusion cylinder barrel 5121, extrusion cylinder piston 5122, extrusion cylinder lock nut 5123, extrusion cylinder air inlet connector 512P, extrusion cylinder exhaust port connector 512R. The extrusion cylinder barrel 5121 is fixed on the module bracket 511 by the extrusion cylinder lock nut 5123 , and the extrusion cylinder air inlet connector 512P and the extrusion cylinder exhaust port connector 512R are installed on the extrusion cylinder barrel 5121 .

The barrel unit 513 includes a barrel, a piston and a barrel pressing cover. As shown in FIG. 4 , the barrel unit 513 specifically includes: a barrel 5131, a piston 5132, a connecting nut 5133, a barrel pressing cover plate 5134, a barrel pressing cover plate locking bolt 5135, a barrel discharge port locking Nut 5136. The barrel 5131 is fixed on the module bracket 511 by the barrel pressing cover plate 5134 and the barrel pressing cover plate locking bolt 5135 . The piston 5132 is installed in the barrel 5131 and is connected with the extrusion cylinder piston 5122 through the connecting nut 5133.

In one embodiment, the barrel pressing cover 5134 is located on the upper part of the barrel 5131, and the barrel 5131 is fixedly connected to the barrel through the barrel pressing cover 5134 and the above-mentioned fasteners. The module bracket 511; the piston 5132 is arranged in the barrel and is connected with the extrusion cylinder piston 5122 of the extrusion pressurizing unit 512, and the lower part of the barrel is provided with a discharge port.

In one embodiment, the extrusion on-off unit includes a module support plate 5141, a module support 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 Cylinder air inlet B pipeline connector 5145B, rotary valve coupling 5146, rotary two-way valve 5147, extrusion nozzle 5148. The module support plate 5141 is fixed on the module bracket 511 by the module support plate fixing bolts 5142, the rotating cylinder 5143 is fixed on the module support plate 5141 by the rotating cylinder fixing bolts 5144, and one end of the rotating two-way valve 5147 is discharged from the material barrel. One end of the rotary valve coupling 5146 is connected with the output shaft of the rotary cylinder 5143, and the other end is connected with the knob of the rotary two-way valve 5147. 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 structure of the light curing unit 515 is shown in FIGS. 4-5 , and the light curing unit 515 includes an annular ultraviolet light projector 5151 , a light emission fiber 5152 , and an annular ultraviolet light projector fixing bolt 5153 . The annular ultraviolet light projector 5151 is fixed on the module bracket 511 by the 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 emission 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 the material in the molding device 5 according to the present invention under different extrusion moving directions; wherein, when the extrusion nozzle 5148 moves in different moving directions, for example, the accompanying drawings In the moving direction A and the moving direction B shown in 6, the extruded material intersects with the annular curing light projection area formed by the curing light projected by the light curing unit 515 to produce a curing effect.

In one embodiment, the curing light source device 6 includes a plurality of ultraviolet light generators, and the ultraviolet light generators are connected with the light-emitting fiber 5152 in the annular ultraviolet light projector 5151 of the corresponding molding module through a light-guiding fiber .

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

Embodiment 2

This embodiment provides an additive manufacturing method based on material extrusion and photocuring composite molding. The method adopts the equipment described in the first embodiment, and the method includes the following steps:

Step 1: Slurry configuration, configure different materials to be molded into slurries, and add a photoinitiator to one or more of the slurries so that they can be cured by ultraviolet light;

Step 2: select the number of molding modules according to the type of material, and configure the corresponding pressurization control module and on-off control module in the extrusion control device according to the number of molding modules;

Step 3: Determine the number of ultraviolet light generators of the curing light source device according to the quantity of the paste to be cured, so that the light wave wavelength of the ultraviolet light generator is consistent with the sensitive wavelength of the photoinitiator in the paste, and connect it with a light guide fiber The ultraviolet light generator and the light-emitting fiber in the corresponding molding module;

Step 4: Fill the slurry and install the molding module, put the slurry of different materials into the barrel of the corresponding molding module, install the barrel to the molding module bracket, and install it in other units of the molding module. After the installation is completed, install multiple molding modules to the module mounting bracket;

Step 5: Equipment initialization, by controlling the pressurization control module and multiple pressurization control valves and multiple on-off control valves of the on-off control module, test the function of the corresponding molding module, and move the three-axis return the platform to zero;

Step 6: The digital model of the part to be formed is sliced and layered to obtain the printing paths of different pastes, and the control instructions of each printing path are optimized. Obtain better shape retention;

Step 7: The equipment starts to form according to the control instructions, and when forming each layer, it preferentially extrudes and solidifies 1-2 layers on the periphery of the part to form a frame structure that is not easily deformed;

Step 8: Complete the molding and remove the part from the three-axis motion platform.

According to the technical solution of this embodiment, the principle of the slurry extrusion process of the molding device of the equipment is as follows:

When a molding module needs to extrude slurry, the pressurization control valve corresponding to the molding module is switched to: the cylinder of the extrusion pressurization unit of the molding module is fed with compressed air, and after a certain time delay, the cylinder is filled with compressed air. If the slurry reaches the extrusion pressure requirement, immediately control the outlet A of the corresponding on-off control valve to conduct, so that the rotary cylinder of the molding module rotates and drives the rotary two-way valve to conduct, and the slurry is extruded; When the molding module needs to stop extruding the slurry, the corresponding pressure control valve of the molding module is switched to: the cylinder of the extrusion pressurizing unit of the molding module enters the exhaust state, and the extrusion pressure of the molding module is pressed. The high-pressure gas in the cylinder of the unit is discharged to release the pressure of the slurry in the barrel, and the corresponding on-off control valve outlet B is controlled to conduct, so that the rotary cylinder of the molding device rotates in the opposite direction and drives the rotary two-way valve to close. Then the extrusion of the slurry was stopped.

According to the technical solution of the present embodiment, the principle of the light curing process of the molding device of the equipment is as follows:

After the slurry is extruded from the molding module, if a slurry has been configured as a curable slurry containing a photoinitiator, and the structure of the slurry in the part to be molded needs to be strengthened, When the material is extruded, turn on the power of the corresponding ultraviolet light generator. Since the key ultraviolet light generator of the molding module is set in a ring, the ultraviolet light corresponding to the paste is projected in a circular shape with the extrusion point as the center, no matter which platform the platform goes to. Directional movement, the extruded slurry can be solidified.

According to the technical scheme of the present invention, when the digital model of the part to be formed is sliced and layered, the extrusion control, the light curing process and the motion set of the three-axis platform are compiled into a control command sequence for the equipment to work independently.

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

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (8)

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:

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 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;

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

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