Particle 3D printer and extrusion mechanism thereof

Abstract

The invention provides a particle 3D printer and an extrusion mechanism thereof, the extrusion mechanism comprises a heating barrel, a relay bin, a storage bin, a screw rod and a motor, a discharge end of the heating barrel is provided with a nozzle, a first discharge port of the relay bin is in butt joint with a feed end of the heating barrel, a second discharge port of the storage bin is in butt joint with a first feed port of the relay bin, and a second discharge port of the relay bin is in butt joint with a second feed port of the screw rod. The screw rod is arranged in the heating material barrel and the relay material bin, an output shaft of the motor is connected with the screw rod, the extrusion mechanism further comprises a heat insulation gasket, the heat insulation gasket is arranged between the feeding end and the first discharging port in a spaced mode, the particle 3D printer is provided with the extrusion mechanism, and the extrusion mechanism can prevent plastic particles from being fused before entering the material barrel.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to an extrusion mechanism and a particle 3D printer provided with the extrusion mechanism. Background Art

[0002] As an important industrial equipment, 3D printers play a key role in many fields. Among them, the granule-fed 3D printing technology can directly use plastic granules for printing, which is particularly suitable for the efficient production of large parts and the realization of complex curved surface structures; at the same time, it can also quickly print out precise tools, fixtures, etc., significantly reducing processing time and cost. The working principle of the granule extrusion 3D printer is similar to the common FDM / FFF (fused deposition modeling) 3D printing, but it is different. Among them, granule 3D printing requires a special extruder, the key component of which is the screw, which rotates in the barrel to transport plastic granules from the silo to the nozzle; the extruder usually has multiple heating zones to melt the plastic into a uniform melt and maintain a constant temperature and flow rate to achieve consistent extrusion. This technology allows direct use of granular materials for printing, avoiding the degradation of material properties that may be caused by multiple heating in traditional wire printing. However, since the heating element is provided on the periphery of the barrel, the heat generated by the heating element is easily transferred to the silo through the barrel, which causes the plastic granules in the silo to melt due to thermal radiation, and ultimately leads to the inability to discharge the material normally. Summary of the invention

[0003] In order to solve the above problems, the main purpose of the present invention is to provide an extrusion mechanism that prevents the plastic particles from melting before entering the barrel.

[0004] Another object of the present invention is to provide a particle 3D printer provided with the above-mentioned extrusion mechanism.

[0005] In order to achieve the main purpose of the present invention, the present invention provides an extrusion mechanism, including a heating barrel, a relay silo, a storage silo, a screw rod and a motor, the discharge end of the heating barrel is provided with a nozzle, the first discharge port of the relay silo is connected to the feed end of the heating barrel, the second discharge port of the storage silo is connected to the first feed port of the relay silo, the screw rod is arranged in the heating barrel and the relay silo, the output shaft of the motor is connected to the screw rod, wherein the extrusion mechanism also includes a thermal insulation gasket, which is arranged between the feed end and the first discharge port.

[0006] As can be seen from the above, placing the thermal insulation gasket between the heating barrel and the relay silo can prevent the heat of the heating barrel from being transferred to the relay silo, thereby preventing the granular consumables in the relay silo from being affected by the heat generated by the heating barrel and causing melting and deterioration, thereby ensuring that the granular consumables can be discharged normally and the extrusion mechanism can perform normal printing operations; in addition, by designing the position of the thermal insulation gasket, the granular consumables first contact the thermal insulation gasket and then enter the heating barrel and / or enter the heating barrel with the help of a spiral rod, thereby effectively avoiding direct contact between the granular consumables and the heating barrel and reducing the risk of premature melting of the granular consumables.

[0007] A preferred solution is that the first through hole of the thermal insulation gasket is in the shape of an inverted cone, the thermal insulation gasket is sleeved on the feed end, the large diameter end of the first through hole is close to the first discharge port, and the hole wall of the first through hole is provided with a first spiral groove group; the inner wall of the heating barrel close to the feed end is provided with a second spiral groove group, and the second spiral groove group is matched and connected with the first spiral groove group.

[0008] As can be seen from the above, the design of the inverted truncated cone-shaped first through hole and the first spiral groove group of the insulation gasket helps to assist the spiral rod to allow the granular consumables to enter the heating barrel more smoothly, avoid the accumulation and blockage of the granular consumables at the feed end, ensure the continuity and uniformity of the nozzle extruding the molten consumables, and thus improve the printing quality.

[0009] A further solution is that a first socket connected to the first through hole is formed at the small diameter end of the thermal insulation gasket close to the first through hole, and a first limiting portion is provided in the first socket; the feed end is inserted into the first socket, and a second limiting portion is provided on the feed end, and the second limiting portion cooperates with the first limiting portion to limit the relative rotation of the thermal insulation gasket and the heating barrel.

[0010] As can be seen from the above, a first plug hole is provided on the insulation gasket and the feed end of the heating barrel is inserted into the first plug hole, which can improve the positioning effect of the insulation gasket and prevent the insulation gasket from being misaligned relative to the feed end of the heating barrel and / or the first discharge port of the relay silo, thereby ensuring that the granular consumables can accurately enter the heating silo; and the design of the first limit part on the insulation gasket and the second limit part on the heating barrel can play an anti-mistake role, ensuring that the first spiral groove group and the second spiral groove group are accurately docked, thereby ensuring the smoothness of the feeding of the granular consumables.

[0011] A further solution is that a first step portion is formed in the first socket, and a first limit portion is formed on the first step portion; a second step portion is formed on the feed end, and a second limit portion is formed on the second step portion, and the second step portion is cooperatively connected with the first step portion; one of the first limit portion and the second limit portion is a slot, and the other is a protrusion.

[0012] As can be seen from the above, this design facilitates the disassembly and assembly between the insulation gasket and the heating barrel, while helping to disperse the pressure on the connection between the two, reduce local stress concentration, and improve the insulation effect.

[0013] A further solution is that the extrusion mechanism also includes a pressure ring, a clamping plate and a locking assembly, the thermal insulation gasket is formed with an annular groove at the periphery of the first through hole, a second plug hole is provided at the first discharge port, the pressure ring is installed in the annular groove and inserted into the second plug hole, the clamping plate has a second through hole, the heating barrel passes through the second through hole, a limit ring is formed on the outer periphery of the heating barrel, the limit ring is connected between the thermal insulation gasket and the clamping plate, and the locking assembly connects the clamping plate and the relay silo.

[0014] As can be seen from the above, this design enables the thermal insulation gasket to be reliably clamped and fixed with the cooperation of the pressure ring, clamping plate, locking assembly, heating barrel and relay silo, and the annular groove of the pressure ring and the thermal insulation gasket can prevent the large diameter end of the first through hole of the thermal insulation gasket from being deformed due to pressure, thereby avoiding misalignment between the large diameter end and the first discharge port of the relay silo, preventing leakage of granular consumables and allowing the granular consumables to smoothly pass through the thermal insulation gasket into the heating barrel.

[0015] Another preferred solution is that the spiral rod has a core shaft and spiral blades, the core shaft has a variable diameter section, a first diameter of the variable diameter section near the feed end is smaller than a second diameter of the variable diameter section near the nozzle, and the spiral blades are spirally wound around the core shaft.

[0016] A further solution is that the second diameter is between 2 and 3 times the first diameter.

[0017] As can be seen from the above, the small diameter end of the spiral rod can enable the granular consumables in the relay silo to move stably toward the heating barrel, and the large diameter end of the spiral rod can ensure that the viscous printing consumables can be reliably extruded from the nozzle.

[0018] A further solution is that the relay silo is provided with a heat dissipation grille; and / or the extrusion mechanism also includes a heat dissipation module, the heat dissipation module includes a heat dissipation fan and an air guide channel, the heat dissipation fan is arranged at the air inlet of the air guide channel, and the air outlet of the air guide channel is arranged toward the extrusion end of the nozzle.

[0019] As can be seen from the above, the heat dissipation grille can provide a certain ventilation and heat dissipation effect for the granular consumables in the relay silo. Combined with the design of the thermal insulation gasket, the temperature in the relay silo is kept between 60°C and 70°C, so as to preheat and dry the granular consumables. The heat dissipation module is used to cool the extruded printing consumables, which ensures the stability of the stacking and molding of the printing consumables and the molding quality of the printed three-dimensional products.

[0020] A further solution is that the thermal insulation gasket is made of polytetrafluoroethylene material.

[0021] As can be seen from the above, this design enables the thermal insulation gasket to have excellent thermal insulation performance, ensuring that the granular consumables in the relay silo will not melt.

[0022] In order to achieve another purpose of the present invention, the present invention provides a particle 3D printer, including a driving mechanism and a printing platform, which also includes the above-mentioned extrusion mechanism, the driving mechanism drives the extrusion mechanism to move relative to the printing platform, and the extrusion end of the nozzle is set toward the printing platform.

[0023] It can be seen from the above that the particle 3D printer equipped with the above-mentioned extrusion mechanism can effectively prevent the granular consumables in the relay hopper from melting and clogging the heating barrel during the printing operation, thereby ensuring that the spiral rod can reliably feed the heating barrel and prevent the heating barrel from being blocked, and ensuring that the nozzle can stably and normally extrude the molten printing consumables. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural diagram of an embodiment of a particle 3D printer of the present invention.

[0025] Figure 2 3D printer of the present invention.

[0026] Figure 3 4 is a cross-sectional view of an extrusion mechanism of an embodiment of a particle 3D printer of the present invention.

[0027] Figure 4 This is a structural diagram of the extrusion mechanism of the particle 3D printer embodiment of the present invention after omitting some components.

[0028] Figure 5 It is a second exploded view of the extrusion mechanism of the 3D printer embodiment of the present invention after omitting some components.

[0029] Figure 6 It is an exploded view of the extrusion mechanism of the 3D printer embodiment of the present invention after omitting some components.

[0030] Figure 7 1 is a structural diagram of a screw rod of an extrusion mechanism of a 3D printer embodiment of the present invention.

[0031] Figure 8 This is a comparison table of relevant experimental data before and after the use of the thermal insulation gasket in the 3D printer embodiment of the present invention.

[0032] The present invention is further described below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0033] Particle 3D Printer Example Reference Figure 1The particle 3D printer 100 includes an extrusion mechanism 101, a driving mechanism 102, and a printing platform 103. In this embodiment, the driving mechanism 102 not only drives the extrusion mechanism 101 to make a planar motion relative to the printing platform 103, but also drives the printing platform 103 to move relative to the extrusion mechanism 101 in the height direction of the particle 3D printer 100, so as to achieve layer-by-layer stacking of printing consumables. Of course, in some embodiments, the printing platform 103 can remain fixed, while the driving mechanism 102 drives the extrusion mechanism 101 to move relative to the printing platform 103 in the height direction of the particle 3D printer 100, so as to achieve layer-by-layer stacking of printing consumables, and the driving mechanism 102 also drives the extrusion mechanism 101 to make a planar motion relative to the printing platform 103.

[0034] Combination Figures 2 to 6 The extrusion mechanism 101 includes a heating barrel 1, a relay bin 2, a storage bin 3, an insulation gasket 4, a pressure ring 5, a clamping plate 6, a locking assembly 7, a screw rod 8, a motor and a heat dissipation module 9.

[0035] The discharge end of the heating barrel 1 is provided with a nozzle 11, which is arranged toward the printing platform 103, so that the molten printing consumables extruded by the nozzle 11 can be stacked layer by layer on the printing platform 103; a heating body 12 is arranged on the periphery of the heating barrel 1 to heat the granular consumables entering the heating barrel 1, so that the granular consumables are melted and extruded from the nozzle 11. The feed end of the heating barrel 1 is connected to the first discharge port 21 of the relay silo 2, so that the granular consumables stored in the relay silo 2 can enter the heating barrel 1 for heating and melting. Among them, the heat-insulating gasket 4 is arranged between the feed end of the heating barrel 1 and the first discharge port 21 of the relay bin 2 to prevent the heating barrel 1 from directly contacting the relay bin 2, thereby blocking the heat of the heating barrel 1 from being transferred to the relay bin 2 to a certain extent, preventing the granular consumables in the relay bin 2 from being melted and woven due to the heat generated by the heating barrel 1, and at the same time ensuring that the granular consumables can smoothly enter the heating barrel 1, ensuring that the extrusion mechanism 101 can perform the printing operation normally. In addition, by designing the position of the heat-insulating gasket 4 as mentioned above, when the granular consumables enter the heating barrel 1, they first contact the heat-insulating gasket and then enter the heating barrel 1 and / or enter the heating barrel 1 with the help of the spiral rod 8, thereby preventing the granular consumables from directly contacting and entering the heating barrel 1, reducing the risk of premature melting of the granular consumables.

[0036] Preferably, the first through hole 41 of the thermal insulation gasket 4 is set to be an inverted truncated cone shape, so that the granular consumables in the relay silo 2 can enter the heating barrel 1 more smoothly, and it is not easy to accumulate or clog at the thermal insulation gasket 4; at the same time, with the assistance of the spiral rod 8 in pushing the material, the continuous and stable feeding of the granular consumables is ensured, thereby ensuring the continuity and uniformity of the nozzle 11 in extruding the molten printing consumables. Among them, the thermal insulation gasket 4 is sleeved on the feed end of the heating barrel 1, so that the thermal insulation gasket 4 covers the end of the feed end of the heating barrel 1, so as to better prevent the heating barrel 1 from contacting the granular consumables at the first discharge port 21 of the relay silo 2; specifically, the large diameter end of the first through hole 41 of the thermal insulation gasket 4 is arranged close to the first discharge port 21 of the relay silo 2, and correspondingly, the small diameter end of the first through hole 41 is arranged close to the feed end of the heating barrel 1, and the small diameter end of the first through hole 41 A first socket 43 is formed at the radial end, and the first socket 43 is connected to the first through hole 41. The feed end of the heating barrel 1 is inserted into the first socket 43. This design helps to improve the positioning effect of the insulation gasket 4, and better prevent the insulation gasket 4 from being misaligned relative to the feed end of the heating barrel 1 and / or the first discharge port 21 of the relay silo 2 after installation, so as to ensure that the granular consumables can accurately enter the heating barrel 1, and are not prone to accumulation and blockage at the junction of the insulation gasket 4 and the heating barrel 1.

[0037] In order to better assist the spiral rod 8 in delivering the granular consumables into the heating barrel 1 and avoid accumulation and blockage of the granular consumables at the feed end of the heating barrel 1, a first spiral groove group 42 is arranged on the hole wall of the first through hole 41 of the thermal insulation gasket 4, and at the same time, a second spiral groove group 13 is provided on the inner wall of the heating barrel 1 near its own feed end, and the second spiral groove group 13 is matched and connected with the first spiral groove group 42, that is, a first spiral groove of the first spiral groove group 42 is connected with a second spiral groove of the second spiral groove group 13, so that the granular consumables can smoothly enter the heating barrel 1 through the first spiral groove and the second spiral groove, so as to further ensure the continuity and uniformity of the nozzle 11 in extruding the molten printing consumables, thereby improving the printing quality.

[0038] Furthermore, a first step portion 431 is formed in the first insertion hole 43 of the heat insulating gasket 4, and a second step portion 14 is formed on the feeding end of the heating barrel 1. When the heating barrel 1 is inserted into the first insertion hole 43, the second step portion 14 is connected with the first step portion 431. This design can facilitate the disassembly and assembly between the heat insulating gasket 4 and the heating barrel 1, and also helps to disperse the pressure on the connection between the two, reduce local stress concentration, and improve the heat insulation effect.

[0039] In addition, a first limiting portion 432 is further provided in the first insertion hole 43 of the heat insulating gasket 4, and a second limiting portion 15 is further provided on the feeding end of the heating barrel 1; when the heating barrel 1 is inserted into the first insertion hole 43, the first limiting portion 432 and the second limiting portion 15 are matched and connected to limit the heat insulating gasket 4 from rotating relative to the heating barrel 1. This design can play a foolproof role in the assembly of the heat insulating gasket 4 and the heating barrel 1, and also ensure that the first spiral groove group 42 and the second spiral groove group 13 can be accurately docked to ensure the smoothness of the granular consumables entering the heating barrel 1. Preferably, the first limiting portion 432 is formed on the first step portion 431, and the second limiting portion 15 is formed on the second step portion 14; wherein, one of the first limiting portion 432 and the second limiting portion 15 is a slot and the other is a convex block, such as in the present embodiment, the first limiting portion 432 is a slot and the second limiting portion 15 is a convex block.

[0040] Furthermore, the heat-insulating gasket 4 is formed with an annular groove 44 at the periphery of the first through hole 41, and the annular groove 44 extends from the large diameter end of the first through hole 41 to the small diameter end of the first through hole 41 in the circumferential direction of the first through hole 41; at the same time, a second plug hole 24 is provided at the first discharge port 21 of the relay silo 2, and the second plug hole 24 is connected to the first discharge port 21, and the second plug hole 24 is located between the bottom of the relay silo 2 and the first discharge port 21. When the pressure ring 5 is assembled, it is installed in the annular groove 44 of the heat-insulating gasket 4 and inserted into the second plug hole 24 of the relay silo 2. A limit ring 16 is formed on the outer periphery of the heating barrel 1, and the limit ring 16 is arranged near the feed end of the heating barrel 1; a second through hole is provided on the clamping plate 6, and when the heating barrel 1 and the clamping plate 6 are assembled, the heating barrel 1 passes through the second through hole, and the clamping plate 6 is located between the limit ring 16 and the nozzle 11; when the clamping plate 6 and the relay bin 2 are assembled, the clamping plate 6 and the relay bin 2 are connected by the locking assembly 7, so that the clamping plate 6 is fixed on the relay bin 2, and at the same time, the clamping plate 6 pushes the limit ring 16, forcing the heating barrel 1, the insulation gasket 4 and the pressure ring 5 to move toward the relay bin 2, so that the pressure ring 5 cooperates with the limit ring 16 to clamp and fix the insulation gasket 4, the insulation gasket 4 cooperates with the relay bin 2 to fix the pressure ring 5, and the clamping plate 6 cooperates with the relay bin 2 to fix the heating barrel 1, the insulation gasket 4 and the pressure ring 5. It can be seen that, with the cooperation of the pressure ring 5, the clamping plate 6, the locking assembly 7, the heating barrel 1 and the relay silo 2, the heat insulating gasket 4 can be reliably clamped and fixed, and the pressure ring 5 cooperates with the annular groove 44 of the heat insulating gasket 4 to prevent the large diameter end of the first through hole 41 of the heat insulating gasket 4 from being deformed due to pressure, thereby avoiding the misalignment between the large diameter end and the first discharge port 21 of the relay silo 2, preventing the granular consumables from leaking and allowing the granular consumables to smoothly pass through the heat insulating gasket 4 into the heating barrel 1. Among them, the heat insulating gasket 4 is preferably made of polytetrafluoroethylene material, so that the heat insulating gasket 4 has excellent heat insulation performance, ensuring that the granular consumables in the relay silo 2 will not melt.

[0041] Preferably, the relay silo 2 is also provided with a heat dissipation grille 23, which can provide a certain ventilation and heat dissipation effect on the granular consumables in the relay silo 2. Combined with the design of the insulation gasket 4, the temperature in the relay silo 2 is between 60°C and 70°C, so as to preheat and dry the granular consumables.

[0042] The storage bin 3 is used to store a large amount of granular consumables. The second discharge port 31 of the storage bin 3 is connected to the first feed port 22 of the relay bin 2, so that the granular consumables in the storage bin 3 can be gradually introduced into the relay bin 2 for preheating and pushed into the heating barrel 1 by the screw rod 8.

[0043] The screw rod 8 is arranged in the heating barrel 1 and the relay silo 2, and the screw rod 8 is connected to the output shaft of the motor, so that the motor can drive the screw rod 8 to rotate, thereby pushing the granular consumables in the relay silo 2 into the heating barrel 1 for heating and melting. The motor is preferably installed on the relay silo 2 and located outside the relay silo 2, and the motor is preferably a stepping motor to achieve accurate feeding of the granular consumables.

[0044] like Figure 7 As shown, the spiral rod 8 has a core shaft 81 and a spiral blade 8282; wherein the core shaft 81 has a variable diameter section, the first diameter φ1 of the variable diameter section near the feed end of the heating barrel 1 is smaller than the second diameter φ2 of the variable diameter section near the nozzle 11, and the small diameter end of the core shaft 81 is connected to the output shaft of the motor; the spiral blade 8282 is spirally wound around the core shaft 81. Preferably, the second diameter φ2 of the variable diameter section of the core shaft 81 is between 2 and 3 times the first diameter φ1. By designing the variable diameter section of the core shaft 81, the small diameter end of the spiral rod 8 can stably push the granular consumables in the relay silo 2 to the heating barrel 1, while the large diameter end of the spiral rod 8 can ensure that the printing consumables that have become viscous and molten can be reliably extruded from the nozzle 11. As in the present embodiment, the first diameter φ1 of the variable diameter section of the core shaft 81 is preferably about 2.7 mm, and the second diameter φ2 of the variable diameter section of the core shaft 81 is preferably about 5.6 mm.

[0045] The heat dissipation module 9 includes a heat dissipation fan 91 and an air guide channel 92, wherein the heat dissipation fan 91 is arranged at the air inlet of the air guide channel 92, and the air outlet of the air guide channel 92 is arranged toward the extrusion end of the nozzle 11. The heat dissipation module 9 is used to cool the extruded printing consumables, and quickly cool the extruded printing consumables to ensure the stability of the stacking and molding of the printing consumables, and to ensure the molding quality of the three-dimensional products formed by printing.

[0046] like Figure 8 As shown, it shows the comparison of relevant experimental data after using the thermal insulation gasket 4 provided by the present invention.

[0047] In summary, it can be seen that by designing the extrusion mechanism 101 of the particle 3D printer 100, during the printing operation of the particle 3D printer 100, there will be no problem of clogging the heating barrel 1 due to the melting of the particle consumables in the relay silo 2, thereby ensuring that the spiral rod 8 can reliably feed the heating barrel 1 and prevent the heating barrel 1 from being blocked, and ensuring that the nozzle 11 can stably and normally extrude the molten printing consumables.

[0048] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Extrusion mechanism, including: A heating barrel, wherein a nozzle is provided at the discharge end of the heating barrel; A relay silo, wherein a first discharge port of the relay silo is connected to a feed end of the heating barrel; A material storage bin, wherein the second material outlet of the material storage bin is connected to the first material inlet of the relay bin; A screw rod, the screw rod is arranged in the heating barrel and the relay silo; A motor, wherein the output shaft of the motor is connected to the screw rod; Features: The extrusion mechanism further comprises a heat insulating gasket, and the heat insulating gasket is arranged between the feed end and the first discharge port.

2. The extrusion mechanism according to claim 1, characterized in that: The first through hole of the heat-insulating gasket is in the shape of an inverted truncated cone, the heat-insulating gasket is sleeved on the feeding end, the large-diameter end of the first through hole is close to the first discharge port, and the hole wall of the first through hole is provided with a first spiral groove group; The inner wall of the heating barrel close to the feeding end is provided with a second spiral groove group, and the second spiral groove group is matched and connected with the first spiral groove group.

3. The extrusion mechanism according to claim 2, characterized in that: The small-diameter end of the heat-insulating gasket close to the first through hole is formed with a first plug hole connected to the first through hole, and a first limiting portion is provided in the first plug hole; The feed end is inserted into the first insertion hole, and a second limiting portion is provided on the feed end. The second limiting portion cooperates with the first limiting portion to limit the relative rotation of the thermal insulation gasket and the heating barrel.

4. The extrusion mechanism according to claim 3, characterized in that: A first step portion is formed in the first insertion hole, and the first limiting portion is formed on the first step portion; A second step portion is formed on the feed end, the second limiting portion is formed on the second step portion, and the second step portion is matched and connected with the first step portion; One of the first limiting portion and the second limiting portion is a slot, and the other is a protrusion.

5. The extrusion mechanism according to claim 3, characterized in that: The extrusion mechanism also includes: A pressure ring, wherein the heat-insulating gasket is formed with an annular groove at the periphery of the first through hole, a second plug hole is provided at the first discharge port, and the pressure ring is installed in the annular groove and inserted into the second plug hole; A clamping plate, wherein the clamping plate has a second through hole, the heating barrel passes through the second through hole, a limiting ring is formed on the outer periphery of the heating barrel, and the limiting ring is connected between the thermal insulation gasket and the clamping plate; A locking assembly connects the clamping plate and the relay silo.

6. The extrusion mechanism according to claim 1, characterized in that: The spiral rod has a core shaft and spiral blades. The core shaft has a variable diameter section. The first diameter of the variable diameter section near the feed end is smaller than the second diameter of the variable diameter section near the nozzle. The spiral blades are spirally wound around the core shaft.

7. The extrusion mechanism according to claim 6, characterized in that: The second diameter is between 2 and 3 times the first diameter.

8. The extrusion mechanism according to any one of claims 1 to 7, characterized in that: The relay silo is provided with a heat dissipation grille; and / or The extrusion mechanism also includes a heat dissipation module, which includes a heat dissipation fan and an air guide channel. The heat dissipation fan is arranged at the air inlet of the air guide channel, and the air outlet of the air guide channel is arranged toward the extrusion end of the nozzle.

9. The extrusion mechanism according to claim 8, characterized in that: The heat insulating gasket is made of polytetrafluoroethylene material.

10. A particle 3D printer, comprising a drive mechanism and a printing platform, characterized in that: It also includes the extrusion mechanism as described in any one of claims 1 to 9, wherein the driving mechanism drives the extrusion mechanism to move relative to the printing platform, and the extrusion end of the nozzle is arranged toward the printing platform.

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