Additive manufacturing device based on injection

Abstract

The invention discloses an injection-based additive manufacturing device, and belongs to the technical field of 3D printing rapid prototyping, the injection-based additive manufacturing device comprises a rack, a supporting plate is fixedly mounted on the rack, a three-dimensional moving assembly is arranged on the rack below the supporting plate, and a vertically arranged machine barrel is fixedly mounted on the supporting plate; an injection nozzle is arranged at the lower end of the machine barrel, the upper end of the machine barrel is connected with a hopper, an injection screw rod is coaxially arranged in the machine barrel, and the upper end of the injection screw rod extends out of the machine barrel and is connected with a rotating power mechanism for driving the injection screw rod to rotate and a body frame structure for melting and extruding deposition products; and the upper end of the injection screw rod is also connected with a lifting power mechanism for driving the injection screw rod to lift, and the lifting power mechanism is used for injecting molten plastic into the body frame structure so as to fill an inner cavity of the body frame structure. According to the method, the same material can be used for forming without any dissimilar material insert or chemical additive, and the strength of the 3D printing product is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing and molding, and in particular relates to an additive manufacturing device based on injection. Background Art

[0002] At present, 3D printing is mainly divided into fused deposition modeling, liquid photosensitive resin photocuring, selective laser sintering, selective laser melting and other technologies. Although different types of 3D printing technologies use different molding materials, molding principles and system characteristics, their basic principles are the same, all of which are "layered manufacturing and layer-by-layer stacking". Because the bonding force between layers is weak, it is easy to cause insufficient strength in the stacking direction. The existing 3D printing internal structure is a superposition of parallel layers. The original filling structure has at least one dimension in the three-dimensional direction that is only solidified and connected by the weak bonding force between the molten materials. The product has the shortcomings of poor tensile strength and shear strength.

[0003] In the prior art, a patent application titled "A method for improving the strength of 3D printing" (application number: 201810929795.2) discloses a method of embedding 3D printed parts with prefabricated parts such as metal to form a combined structural 3D printed workpiece with metal embedded parts to improve the overall strength of the product. However, this method requires embedded metal parts, which increases the weight of the product and reduces its flexibility.

[0004] In addition, a patent application titled "A method for increasing the strength of 3D printed products" (application number: 201510922876.6) discloses a method for improving the interlayer bonding strength by adding auxiliary solvents, that is, while the print head extrude the filaments, the auxiliary solvents are used to dissolve the surface of the printed accumulated filaments, so that the adjacent layers are welded and solidified. However, this method requires additional additives.

[0005] Therefore, in the field of 3D printing rapid prototyping technology, there is still a need for research and improvement of injection-based additive manufacturing devices, which is also a research hotspot and focus in the field of 3D printing rapid prototyping technology, and is also the starting point for the completion of the present invention. Summary of the invention

[0006] To this end, the technical problem to be solved by the present invention is: to provide an injection-based additive manufacturing device to solve the technical problem of insufficient strength in the stacking direction of existing fused deposition modeling products.

[0007] In order to solve the above technical problems, the technical solution of the present invention is: an injection-based additive manufacturing device, comprising a frame, a support plate is fixedly installed on the frame, a three-dimensional moving component is provided on the frame below the support plate, a vertically arranged barrel is fixedly installed on the support plate, an injection nozzle is provided at the lower end of the barrel, the upper end of the barrel is connected to a hopper, an injection screw is coaxially arranged in the barrel, the upper end of the injection screw extends out of the barrel and is connected to a rotating power mechanism that drives the injection screw to rotate, and is used for a body frame structure of a melt-extruded deposited product, the upper end of the injection screw is also connected to a lifting power mechanism that drives the injection screw to rise and fall, and is used for injecting molten plastic into the body frame structure to fill the inner cavity of the body frame structure.

[0008] As an improvement, the injection nozzle includes a shell installed on the barrel, a heating wire is provided on the outer periphery of the shell, a valve body fixed to the shell is provided in the shell, a melt flow channel connected to the barrel is provided on the shell, a blind hole facing the melt flow channel is provided on the valve body, a valve core for blocking the melt flow channel is slidably installed in the blind hole, a compression spring is provided between the valve core and the valve body, the compression spring is constrained and installed in the blind hole, a nozzle body is provided on the shell, a discharge hole is provided on the nozzle body, and the discharge hole is connected to the melt flow channel.

[0009] As a further improvement, the discharge end of the nozzle body is shaped like a spherical crown.

[0010] As a further improvement, the three-dimensional moving component includes a vertical moving platform vertically slidably installed on the frame, and a cross-arranged linear moving module is installed on the vertical moving platform. A printing lower base plate, a printing heating plate and a printing upper base plate are installed on the linear moving module in sequence from bottom to top.

[0011] As a further improvement, a sealing platform is installed on the upper surface of the printing upper base plate, and at least one sealing groove matching the shape of the discharge end of the nozzle body is provided on the sealing platform.

[0012] As an improvement, the lifting power mechanism includes a fixed plate fixedly mounted on the support plate through a guide column, a lifting plate is provided between the fixed plate and the support plate, the lifting plate is slidably mounted on the guide column, a screw sleeve driven by a lifting motor is rotatably mounted on the fixed plate, a lead screw threadedly connected to the screw sleeve is fixedly mounted on the lifting plate, and the upper end of the injection screw is rotatably mounted on the lifting plate.

[0013] As a further improvement, the rotary power mechanism includes a rotary motor fixedly mounted on the lifting plate, and a power output shaft of the rotary motor is drivingly connected to the injection screw.

[0014] As an improvement, the lower end of the injection screw is provided with a non-return structure, and the non-return structure includes a conical end head fixedly mounted on the end of the injection screw, and the large end of the conical end head is provided with a plurality of grooves. The end of the injection screw is provided with a non-return ring, and a flow channel is formed between the non-return ring and the mounting section of the injection screw. The outer diameter of the non-return ring is matched with the inner diameter of the barrel, and the lower end of the non-return ring is provided with a plurality of protrusions matched with the grooves.

[0015] As another improvement, the compression section and the metering section of the injection screw are both connected in series with a flow dividing element.

[0016] As a further improvement, the diverter element includes a cylinder coaxially arranged with the injection screw, and a plurality of diverter edges are arranged along the circumference of the outer circumference of the cylinder. The diverter edges gradually increase in the radial height of the injection screw along the axial direction of the injection screw, and the width of the diverter edges gradually narrows. The extension directions of two adjacent diverter edges are opposite or the extension directions of two adjacent diverter edges are the same.

[0017] After adopting the above technical solution, the beneficial effects of the present invention are:

[0018] The present invention can complete the 3D additive manufacturing of the entire product using only an injection screw and a three-dimensional moving component. The injection process and the melt extrusion process share a plasticizing system. The body frame structure of the product is first melt-extruded and deposited, and then molten plastic is injected into the cavity of the body frame structure to fill the internal cavity. This can effectively enhance the strength and performance of the 3D printed product, while increasing the production speed of 3D printing, expanding the industrial application scope of 3D printed products, and solving the problem of insufficient strength in the stacking direction of traditional fused deposition molding products. Without the aid of external inserts or additives, the strength and printing efficiency of 3D printed products can be significantly improved.

[0019] Since the compression spring of the injection nozzle is enclosed in the blind hole, the contact between the compression spring and the molten material is avoided, which can prevent the molten material from cooling down and affecting the normal use of the compression spring in the injection nozzle when it works again, effectively increasing the service life of the compression spring in the injection nozzle.

[0020] Since the sealing platform is provided with at least one sealing groove which is adapted to the shape of the discharge end of the nozzle body, before injection, when the injection screw rotates and retreats, the front end of the nozzle body contacts the sealing groove of the sealing platform to seal the discharge hole of the nozzle body, which can effectively prevent drooling and provide the back pressure required for the injection screw to retreat.

[0021] Since the check structure can rotate with the rotation of the injection screw, it has better melt mixing ability and can effectively prevent insufficient mixing. At the same time, there is no relative rolling between the claw-shaped check ring and the injection screw, thus avoiding shear overheating and contamination of the molten material between the injection screw and the check ring.

[0022] Since the injection screw is provided with a diverter element, radial convection is enhanced. The diverter element can improve the convective heat exchange with the barrel. The height of the diverter edge in the radial direction of the injection screw gradually increases along the axial direction of the injection screw to form a slope, which causes the melt to flow radially. A convergent flow channel can be formed along the diverter edge to produce tensile flow, which enhances the mixing of the melt. In addition, multiple slope structures are evenly distributed circumferentially, which makes the melt diverted and converged, and constantly disturbs the flow, thereby enhancing mixing and heat transfer, and making the injection screw have better plasticizing and mixing capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0024] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0025] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0026] Figure 2 is a schematic structural diagram of an injection nozzle in an embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of the structure of a three-dimensional mobile component in an embodiment of the present invention;

[0028] Figure 4 is a schematic structural diagram of a sealing platform in an embodiment of the present invention;

[0029] Figure 5 Schematic diagram of the transmission three-dimensional structure of the injection screw in the embodiment of the present invention;

[0030] Figure 6 Schematic diagram of the transmission structure of the injection screw in the embodiment of the present invention;

[0031] Figure 7 Schematic diagram of the installation structure of the screw sleeve in the embodiment of the present invention;

[0032] Figure 8 Schematic diagram of the installation structure of the upper end of the injection screw in an embodiment of the present invention;

[0033] Fig. 9 Schematic diagram of the installation structure of the barrel in the embodiment of the present invention;

[0034] Fig.10 2 is a schematic structural diagram of a backflow prevention structure according to an embodiment of the present invention;

[0035] Fig.11 is a structural schematic diagram of a shunt element in an embodiment of the present invention;

[0036] Fig.12 is another structural schematic diagram of a shunt element in an embodiment of the present invention;

[0037] In the figure: 1, frame, 2, support plate, 3, three-dimensional moving component, 301, vertical moving platform, 302, cross-arranged linear moving module, 303, printing bottom plate, 304, printing heating plate, 305, printing upper bottom plate, 306, sealing platform, 307, blocking groove, 4, barrel, 5, injection nozzle, 501, shell, 502, valve body, 503, melt flow channel, 504, heating wire, 505, valve core, 506, compression spring, 507, nozzle body, 508, discharge hole, 6 , injection screw, 7, lifting power mechanism, 701, fixed plate, 702, lifting plate, 703, guide column, 704, lifting motor, 705, screw sleeve, 706, screw, 8, rotating power mechanism, 801, rotating motor, 9, non-return structure, 901, tapered end, 902, non-return ring, 903, slot, 904, protrusion, 10, connecting rod, 11, universal joint, 12, fan, 13, hopper, 14, fixed seat, 15, diverter element, 1501, column, 1502, diverter edge. DETAILED DESCRIPTION

[0038] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The terms such as "front", "back", "left", "right", "inside", "outside", "middle", etc. cited in this specification are only for the convenience of description and are not intended to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as within the scope of implementation of the present invention without substantially changing the technical content.

[0040] like Figure 1 As shown, an injection-based additive manufacturing device includes a frame 1, a support plate 2 is fixedly mounted on the frame 1, a three-dimensional moving component 3 is provided on the frame 1 below the support plate 2 to achieve three-dimensional direction and six degrees of freedom movement, a vertically arranged barrel 4 is fixedly mounted on the support plate 2, an injection nozzle 5 is provided at the lower end of the barrel 4, and the injection nozzle 5 is usually fixedly mounted on the end of the barrel 4 through a thread or a flange, the upper end of the barrel 4 is connected to a hopper 13, and an insulation sleeve is usually installed outside the barrel 4, which can be a traditional electric heating ring, or an infrared heater or an electromagnetic induction heater. The barrel 4 is heated and kept warm, and an injection screw 6 is coaxially arranged in the barrel 4. The upper end of the injection screw 6 extends out of the barrel 4 and is connected to a rotating power mechanism 8 for driving the injection screw 6 to rotate, and is used to melt-extrude the body frame structure of the deposited product. The upper end of the injection screw 6 is also connected to a lifting power mechanism 7 for driving the injection screw 6 to rise and fall, and is used to inject molten plastic into the body frame structure to fill the inner cavity of the body frame structure, and finally complete the 3D additive manufacturing of the entire product, thereby achieving a significant improvement in the strength and printing efficiency of the 3D printed product without the aid of external inserts or additives.

[0041] A fan 12 can be set on the support plate 2 or around the frame 1. Usually, the fan 12 is fixed to the lower part of the support plate 2 or around the frame 1 through a connecting rod 10 and a universal joint 11. The blowing direction is changed according to the use requirements during printing to meet the cooling requirements of the printed products. Two or more fans 12 can be set as needed.

[0042] The fan 12 may be a hot air device with an electric heating wire, which can be adjusted in gears to achieve air supply at different temperatures, preferably in a temperature range from room temperature to 100°C.

[0043] The injection nozzle 5 is a switch type nozzle to control the opening and closing of the injection nozzle 5, effectively prevent drooling and provide injection back pressure. Specifically, Figure 2As shown, the injection nozzle 5 includes a shell 501 installed on the barrel 4. The shell 501 is usually a two-half structure. A heating wire 504 is provided on the outer periphery of the shell 501 to ensure that the molten material does not cool in the shell 501 and prevent the condensed material from clogging the injection nozzle 5. A valve body 502 fixed to the shell 501 is provided in the shell 501. The valve body 502 is installed between the two halves of the shell 501 through a flange. The shell 501 is provided with a melt flow channel 503 connected to the barrel 4. The valve body 502 is provided with a blind hole facing the melt flow channel 503. A valve core 505 for blocking the melt flow channel 503 is slidably installed in the blind hole. The valve core 505 and the valve body 502 are connected. A compression spring 506 is provided in the housing 501, and the compression spring 506 is constrained and installed in the blind hole. One end of the compression spring 506 abuts against the valve core 505, and the other end abuts against the end of the blind hole. A nozzle body 507 is provided on the housing 501, and a discharge hole 508 is provided on the nozzle body 507. The discharge hole 508 is connected to the melt flow channel 503. When the pressure of the melt in the barrel 4 reaches the injection pressure, the compression spring 506 is compressed, the valve core 505 is pushed into the valve body 502, the melt flow channel 503 is opened, the melt flows through, and finally flows out through the nozzle body 507. When the extrusion or injection is completed, the valve core 505 is lifted by the compression spring 506, and the melt flow channel 503 is closed. Since the compression spring 506 is enclosed in the blind hole, the contact between the compression spring 506 and the melt is avoided, and the normal use of the compression spring 506 in the injection nozzle 5 can be prevented from being affected by the cooling of the molten material when it works again, which effectively increases the service life of the compression spring 506 in the injection nozzle 5.

[0044] like Figure 3 As shown, the three-dimensional moving component 3 includes a vertical moving platform 301 which is vertically slidably installed on the frame 1. The vertical moving platform 301 is usually slidably installed on a vertically arranged slide rail through a slider. The vertical moving platform 301 can realize lifting and lowering movement to ensure the Z-axis movement of the three-dimensional moving component 3. A cross-arranged linear moving module 302 is installed on the vertical moving platform 301. The cross-arranged linear moving module 302 is a combination of two groups of slide rail sliders arranged up and down to realize the free movement of the three-dimensional moving component 3 in the X-axis and Y-axis directions. The printing lower base plate 303, the printing heating plate 304 and the printing upper base plate 305 are installed in sequence from bottom to top on the linear moving module located above to ensure that the molten material is quickly solidified and formed after printing. A sealing platform 306 is installed on the upper surface of the printing upper base plate 305, and the discharge end of the nozzle body 507 is shaped like a spherical crown, as shown in FIG. Figure 4 As shown, the sealing platform 306 is provided with at least one sealing groove 307 which is adapted to the shape of the discharge end of the nozzle body 507. Before injection, when the injection screw 6 rotates and retreats, the front end of the nozzle body 507 contacts the sealing groove 307 of the sealing platform 306 to seal the discharge hole 508 of the nozzle body 507, which can effectively prevent drooling and provide the injection screw 6 with the back pressure required for retreating.

[0045] like Figure 5 and Figure 6 As shown, the lifting power mechanism 7 includes a fixed plate 701 fixedly mounted on the support plate 2 through four guide pillars 703, a lifting plate 702 is provided between the fixed plate 701 and the support plate 2, the lifting plate 702 is slidably mounted on the guide pillars 703, and a screw sleeve 705 driven by a lifting motor 704 is rotatably mounted on the fixed plate 701, as shown in FIG. Figure 7 As shown, the screw sleeve 705 is installed on the fixed plate 701 through a thrust bearing. Usually, the lifting motor 704 is connected to the screw sleeve 705 through a belt drive, a chain drive or a gear drive, that is, a driven pulley, a driven sprocket or a driven gear is fixed on the screw sleeve 705 to drive the screw sleeve 705 to rotate. A screw 706 threadedly connected to the screw sleeve 705 is installed on the lifting plate 702. The end of the screw 706 is usually fixed on the lifting plate 702. A shoulder is usually provided at the end of the screw 706 to apply an axial force to the lifting plate 702. The rotation of the screw sleeve 705 drives the screw 706 to move axially to achieve the lifting and lowering of the lifting plate 702. The upper end of the injection screw 6 is rotatably installed on the lifting plate 702, as shown in FIG. Figure 8 As shown, in order to enable the lifting plate 702 to drive the injection screw 6 to move up and down, countersunk holes are set on both surfaces of the lifting plate 702, and thrust bearings are installed respectively. The upper end of the injection screw 6 is installed on the lifting plate 702 through the thrust bearing. The injection screw 6 is provided with a shoulder for positioning the thrust bearing on the lower surface of the lifting plate 702, and the thrust bearing on the upper surface of the lifting plate 702 is positioned by a round nut or a fixing cap. Fig. 9 As shown, the barrel 4 passes through the support plate 2 and is fixed on the support plate 2 through a fixing seat 14. Specifically, an external thread is provided at the upper end of the barrel 4, and the barrel 4 is fixed to the fixing seat 14 through a locking nut matched with the external thread of the barrel 4. The injection screw 6 is inserted from the upper end of the barrel 4 and can realize rotation and lifting motion in the barrel 4, thereby realizing the two functions of extrusion and injection.

[0046] The rotating power mechanism 8 includes a rotating motor 801 fixedly mounted on the lifting plate 702. The power output shaft of the rotating motor 801 is transmission-connected to the injection screw 6. The injection screw 6 is driven to rotate by the rotating motor 801. The rotating motor 801 and the injection screw 6 can be connected by belt drive, chain drive or gear drive. That is to say, a corresponding driven pulley, driven sprocket or driven gear needs to be fixedly mounted on the injection screw 6. Those skilled in the art can choose to use it according to their needs, which will not be elaborated here.

[0047] The lower end of the injection screw 6 is provided with a non-return structure 9, which can be an annular non-return ring, a rolling ball non-return ring, a non-return ball, a pin-type non-return ring, etc. The non-return structure 9 used in the present invention is as follows: Fig.10As shown, the non-return structure 9 includes a tapered end head 901 fixedly mounted on the end of the injection screw 6, the large end of the tapered end head 901 is mounted on the end of the injection screw 6 by means of threads, the large end of the tapered end head 901 is provided with a plurality of slots 903, the end of the injection screw 6 is sleeved with a non-return ring 902, a flow channel is formed between the non-return ring 902 and the mounting section of the injection screw 6, a limiting shoulder is provided on the side of the mounting section of the injection screw 6 away from the tapered end head 901, for limiting the moving position of the non-return ring 902, the outer diameter of the non-return ring 902 is matched with the inner diameter of the barrel 4, the lower end of the non-return ring 902 is provided with a plurality of protrusions 904 matched with the slots 903, in order to facilitate the protrusions 904 to be inserted into the slots 903, the protrusions 904 and the slots 903 are respectively made into wedge shapes, the width of the non-return ring 902 is smaller than the length of the mounting section of the injection screw 6, and Moreover, the maximum length of the cooperation between the protrusion 904 and the slot 903 is greater than the stroke of the check ring 902 in the installation section of the injection screw 6, ensuring that the protrusion 904 does not fall out of the slot 903. When the injection screw 6 is rotated for extrusion or rotated backward for plasticization, the check ring 902 can be moved forward and mounted on the tapered end 901, rotating with the rotation of the injection screw 6, and the melt enters the front part of the tapered end 901 through the circulation channel; when the injection screw 6 is injected, the check ring 902 contacts the limit shoulder, thereby blocking the circulation channel, and is pushed under the action of the injection screw 6, and moves downward with the injection screw 6. This has better melt mixing ability and can effectively prevent insufficient mixing. At the same time, there is no relative tumbling between the claw-shaped check ring 902 and the injection screw 6, thereby avoiding shear overheating and contamination of the molten material between the injection screw 6 and the check ring 902.

[0048] The compression section and the metering section of the injection screw 6 are both connected in series with a flow dividing element 15. Adjacent flow dividing elements 15 can be arranged at intervals or continuously. The flow dividing element 15 includes a column 1501 coaxially arranged with the injection screw 6. The outer periphery of the column 1501 is provided with a plurality of flow dividing edges 1502 along the circumference. Fig.11 As shown, the height of the splitter rib 1502 in the radial direction of the injection screw 6 gradually increases along the axial direction of the injection screw 6 to form a climbing slope, and the width of the splitter rib 1502 gradually narrows, and the extension directions of two adjacent splitter ribs 1502 are opposite, or, as shown in FIG. Fig.12 As shown, the extension direction of two adjacent diverter edges 1502 is the same, which strengthens the radial convection. The diverter element 15 can improve the convective heat exchange with the barrel 4. Due to the existence of the slope, the melt flows radially, and a convergent flow channel can be formed along the diverter edge 1502, resulting in tensile flow, which strengthens the mixing of the melt. In addition, multiple slope structures are evenly distributed circumferentially, so that the melt is diverted and converged, and the flow is continuously disturbed, which strengthens mixing and heat transfer, and makes the injection screw 6 have better plasticizing and mixing capabilities.

[0049] In summary, the embodiment of the present invention uses a shared plasticizing system through the injection process and the melt extrusion process, first melts and extrude the body frame structure of the deposition product, and then injects molten plastic into the cavity of the body frame structure to fill the internal cavity. This can effectively enhance the strength and performance of the 3D printed product, while increasing the production speed of 3D printing, expanding the industrial application scope of 3D printed products, and solving the shortcoming of insufficient strength in the stacking direction of traditional fused deposition modeling products.

[0050] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, these modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. An injection-based additive manufacturing device, comprising a frame, a support plate fixedly mounted on the frame, and a three-dimensional moving component disposed on the frame below the support plate, characterized in that: A vertically arranged barrel is fixedly mounted on the support plate, an injection nozzle is arranged at the lower end of the barrel, the upper end of the barrel is connected to a hopper, an injection screw is coaxially arranged in the barrel, the upper end of the injection screw extends out of the barrel and is connected to a rotating power mechanism that drives the injection screw to rotate, and is used for the body frame structure of the melt-extruded deposited product, and the upper end of the injection screw is also connected to a lifting power mechanism that drives the injection screw to lift and lower, and is used for injecting molten plastic into the body frame structure to fill the inner cavity of the body frame structure.

2. The injection-based additive manufacturing device according to claim 1, characterized in that The injection nozzle includes a shell installed on the barrel, a heating wire is provided on the outer periphery of the shell, a valve body fixed to the shell is provided in the shell, a melt flow channel connected to the barrel is provided on the shell, a blind hole facing the melt flow channel is provided on the valve body, a valve core for blocking the melt flow channel is slidably installed in the blind hole, a compression spring is provided between the valve core and the valve body, the compression spring is constrained and installed in the blind hole, a nozzle body is provided on the shell, a discharge hole is provided on the nozzle body, and the discharge hole is connected to the melt flow channel.

3. The injection-based additive manufacturing device according to claim 2, characterized in that The discharge end of the nozzle body is in the shape of a spherical crown.

4. The injection-based additive manufacturing device according to claim 3, characterized in that The three-dimensional moving component includes a vertical moving platform vertically slidably mounted on the frame, a cross-arranged linear moving module is mounted on the vertical moving platform, and a printing lower base plate, a printing heating plate and a printing upper base plate are sequentially mounted on the linear moving module from bottom to top.

5. The injection-based additive manufacturing device according to claim 4, characterized in that A sealing platform is installed on the upper surface of the printing upper base plate, and at least one sealing groove matching the shape of the discharge end of the nozzle body is provided on the sealing platform.

6. The injection-based additive manufacturing device according to claim 1, characterized in that The lifting power mechanism includes a fixed plate fixedly mounted on the support plate through a guide column, a lifting plate is provided between the fixed plate and the support plate, the lifting plate is slidably mounted on the guide column, a screw sleeve driven by a lifting motor is rotatably mounted on the fixed plate, a lead screw threadedly connected to the screw sleeve is fixedly mounted on the lifting plate, and the upper end of the injection screw is rotatably mounted on the lifting plate.

7. The injection-based additive manufacturing device according to claim 6, characterized in that The rotary power mechanism comprises a rotary motor fixedly mounted on the lifting plate, and a power output shaft of the rotary motor is drivingly connected to the injection screw.

8. The injection-based additive manufacturing device according to claim 2, characterized in that A non-return structure is provided at the lower end of the injection screw, and the non-return structure includes a conical end head fixedly mounted on the end of the injection screw, and a plurality of grooves are provided at the large end of the conical end head. A non-return ring is mounted on the end of the injection screw, and a flow channel is formed between the non-return ring and the mounting section of the injection screw. The outer diameter of the non-return ring is matched with the inner diameter of the barrel, and the lower end of the non-return ring is provided with a plurality of protrusions matched with the grooves.

9. The injection-based additive manufacturing device according to any one of claims 1 to 8, characterized in that The compression section and the metering section of the injection screw are both connected in series with diverter elements.

10. The injection-based additive manufacturing device according to claim 9, characterized in that The diverter element includes a cylinder coaxially arranged with the injection screw, and a plurality of diverter edges are arranged along the circumference of the outer circumference of the cylinder. The diverter edges gradually increase in the radial height of the injection screw along the axial direction of the injection screw, and the width of the diverter edges gradually narrows. The extension directions of two adjacent diverter edges are opposite or the extension directions of two adjacent diverter edges are the same.

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