Particle 3D printer and its extrusion mechanism

Abstract

The utility model provides a kind of granule 3D printer and its extrusion mechanism, extrusion mechanism includes heating barrel, relay hopper, storage hopper, screw rod and motor, the discharge end of heating barrel is equipped with nozzle, the first discharge port of relay hopper is butt joint with the feed end of heating barrel, the second discharge port of storage hopper is butt joint with the first feed port of relay hopper, screw rod is located in heating barrel and relay hopper, the output shaft of motor is connected with screw rod, wherein, extrusion mechanism further includes heat insulation washer, heat insulation washer is separately arranged between feed end and first discharge port, granule 3D printer is equipped with the extrusion mechanism, and the extrusion mechanism can avoid that melting occurs before plastic granule enters barrel.

Description

Technical Field

[0001] This utility model relates to the field of 3D printing technology, specifically to an extrusion mechanism and a particle 3D printer equipped with the extrusion mechanism. Background Technology

[0002] 3D printers, as important industrial equipment, play a crucial role in many fields. Particle-fed 3D printing technology, which directly utilizes plastic granules for printing, is particularly suitable for the efficient production of large parts and the realization of complex curved surface structures. Simultaneously, it can quickly print precise tools and fixtures, significantly reducing processing time and costs. The working principle of particle extrusion 3D printers is similar to, but also different from, common FDM / FFF (Fused Deposition Modeling) 3D printing. Particle 3D printing requires a special extruder, the key component of which is the screw. The screw rotates within the barrel, conveying plastic granules from the hopper to the nozzle. The extruder typically has multiple heating zones, melting the plastic into a uniform melt and maintaining a constant temperature and flow rate for consistent extrusion. This technology allows for direct printing using granular materials, avoiding material degradation that can occur with repeated heating in traditional filament printing. However, because the barrel has heating elements on its outer periphery, the heat generated by these elements can easily be conducted through the barrel to the hopper, causing the plastic granules in the hopper to melt due to thermal radiation, ultimately preventing proper feeding. Summary of the Invention

[0003] To address the aforementioned problems, the main objective of this invention is to provide an extrusion mechanism that prevents plastic particles from melting before entering the barrel.

[0004] Another objective of this invention is to provide a particle 3D printer equipped with the aforementioned extrusion mechanism.

[0005] To achieve the main objective of this utility model, this utility model provides an extrusion mechanism, including a heating cylinder, a relay hopper, a storage hopper, a screw rod, and a motor. The discharge end of the heating cylinder is provided with a nozzle. The first discharge port of the relay hopper is connected to the feed end of the heating cylinder. The second discharge port of the storage hopper is connected to the first feed port of the relay hopper. The screw rod is disposed inside the heating cylinder and the relay hopper. The output shaft of the motor is connected to the screw rod. The extrusion mechanism also includes a heat insulation gasket, which is disposed between the feed end and the first discharge port.

[0006] As can be seen from the above, placing the heat insulation gasket between the heating cylinder and the relay hopper can prevent the heat from the heating cylinder from being transferred to the relay hopper. This prevents the granules in the relay hopper from melting or deteriorating due to the heat generated by the heating cylinder, ensuring that the granules can be fed normally and the extrusion mechanism can perform normal printing operations. In addition, by designing the position of the heat insulation gasket, the granules first contact the heat insulation gasket and then enter the heating cylinder and / or enter the heating cylinder through the screw rod, effectively avoiding direct contact between the granules and the heating cylinder and reducing the risk of premature melting of the granules.

[0007] A preferred embodiment is that the first through hole of the heat insulation gasket is in the shape of an inverted frustum, the heat insulation gasket is fitted 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 cylinder near 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 frustum-shaped first through hole and the first spiral groove group of the heat insulation gasket helps the auxiliary spiral rod to allow the granular consumable to enter the heating barrel more smoothly, avoids the accumulation and blockage of the granular consumable at the feed end, ensures the continuity and uniformity of the nozzle extrusion of molten consumable, and thus improves the printing quality.

[0009] A further embodiment is that the small-diameter end of the heat insulation gasket near the first through hole is formed with a first insertion hole communicating with the first through hole, and a first limiting part is provided in the first insertion hole; the feeding end is inserted into the first insertion hole, and a second limiting part is provided on the feeding end, the second limiting part cooperating with the first limiting part to restrict the relative rotation of the heat insulation gasket and the heating cylinder.

[0010] As can be seen from the above, the first insertion hole on the heat insulation gasket and the insertion of the heating cylinder feed end into the first insertion hole can improve the positioning effect of the heat insulation gasket, prevent the heat insulation gasket from being misaligned relative to the feed end of the heating cylinder and / or the first discharge port of the relay hopper, and ensure that the granular consumables can accurately enter the heating hopper; while the design of the first limiting part on the heat insulation gasket and the second limiting part on the heating cylinder can play a foolproof role, ensuring that the first spiral groove group and the second spiral groove group are accurately connected, and ensuring the smooth feeding of granular consumables.

[0011] A further proposed solution is that a first step portion is formed inside the first insertion hole, and a first limiting portion is formed on the first step portion; a second step portion is formed on the feed end, and a second limiting portion is formed on the second step portion, with the second step portion and the first step portion engaging and connecting; one of the first limiting portion and the second limiting portion is a slot, and the other is a protrusion.

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

[0013] A further embodiment includes a pressure ring, a clamping plate, and a locking assembly in the extrusion mechanism. The heat insulation gasket has an annular groove formed around the first through hole, and a second insertion hole is provided at the first discharge port. The pressure ring is installed in the annular groove and inserted into the second insertion hole. The clamping plate has a second through hole, and the heating cylinder passes through the second through hole. A limit ring is formed on the outer periphery of the heating cylinder. The limit ring is connected between the heat insulation gasket and the clamping plate. The locking assembly connects the clamping plate and the relay hopper.

[0014] As can be seen from the above, this design enables the heat insulation gasket to be reliably clamped and fixed with the cooperation of the pressure ring, clamping plate, locking assembly, heating cylinder and relay hopper. The annular groove of the pressure ring and the heat insulation gasket can prevent the large-diameter end of the first through hole of the heat insulation gasket from deforming due to pressure, thereby avoiding misalignment between the large-diameter end and the first outlet of the relay hopper, preventing leakage of granular consumables and allowing the granular consumables to smoothly pass through the heat insulation gasket into the heating cylinder.

[0015] Another preferred embodiment is that the screw has a mandrel and helical blades, the mandrel 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, and the helical blades are spirally wound around the mandrel.

[0016] A further proposed approach is to have a second diameter that is between two and three times the diameter of the first diameter.

[0017] As can be seen from the above, the small-diameter end of the screw rod enables the granular consumables in the relay hopper to move stably towards the heated barrel, while the large-diameter end of the screw rod ensures that the viscous printing consumables can be reliably extruded from the nozzle.

[0018] A further improvement is that the relay hopper is equipped with a heat dissipation grid; and / or the extrusion mechanism also includes a heat dissipation module, which includes a heat dissipation fan and an air guide channel, with the heat dissipation fan located at the air inlet of the air guide channel and the air outlet of the air guide channel facing the extrusion end of the nozzle.

[0019] As can be seen from the above, the heat dissipation grille can provide a certain degree of ventilation and heat dissipation for the granular consumables in the relay hopper. Combined with the design of the heat insulation gasket, the temperature inside the relay hopper is kept between 60℃ and 70℃, which can preheat and dry the granular consumables. The heat dissipation module is used to cool the printing consumables that are extruded and formed. It is used to cool the printing consumables quickly after extrusion and form, ensuring the stability of the stacking and forming of the printing consumables and ensuring the forming quality of the printed 3D products.

[0020] A further alternative is to use heat-insulating gaskets made of polytetrafluoroethylene (PTFE).

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

[0022] To achieve another objective of this utility model, this utility model provides a particle 3D printer, including a drive mechanism and a printing platform, wherein the extrusion mechanism described above is also included. The drive mechanism drives the extrusion mechanism to move relative to the printing platform, and the extrusion end of the nozzle is arranged facing the printing platform.

[0023] As can be seen from the above, the particle 3D printer equipped with the above extrusion mechanism can effectively prevent the particle consumables in the relay hopper from melting and clogging the heating cylinder during the printing operation, thereby ensuring that the screw can reliably feed the heating cylinder and prevent the heating cylinder from being blocked, and ensuring that the nozzle can stably and normally extrude the molten printing consumables. Attached Figure Description

[0024] Figure 1 This is a structural diagram of an embodiment of the particle 3D printer of this utility model.

[0025] Figure 2 This is a structural diagram of the extrusion mechanism of an embodiment of the particle 3D printer of this utility model.

[0026] Figure 3 This is a cross-sectional view of the extrusion mechanism of an embodiment of the particle 3D printer of this utility model.

[0027] Figure 4 This is a structural diagram of the extrusion mechanism of an embodiment of the particle 3D printer of this utility model, with the first part of the component omitted.

[0028] Figure 5 This is an exploded view of the second omitted part of the extrusion mechanism of an embodiment of the 3D printer of this utility model.

[0029] Figure 6 This is an exploded view of the third omitted component of the extrusion mechanism in an embodiment of the 3D printer of this utility model.

[0030] Figure 7 This is a structural diagram of the screw rod of the extrusion mechanism in an embodiment of the 3D printer of this utility model.

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0032] Example of a particle 3D printer

[0033] Reference Figure 1The particle 3D printer 100 includes an extrusion mechanism 101, a drive mechanism 102, and a printing platform 103. In this embodiment, the drive mechanism 102 drives the extrusion mechanism 101 to perform planar motion relative to the printing platform 103, and also drives the printing platform 103 to move relative to the extrusion mechanism 101 in the height direction of the particle 3D printer 100, thereby achieving layer-by-layer stacking of printing consumables. Of course, in some embodiments, the printing platform 103 may remain fixed, while the drive 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, thereby achieving layer-by-layer stacking of printing consumables, and the drive mechanism 102 also drives the extrusion mechanism 101 to perform planar motion relative to the printing platform 103.

[0034] Combination Figures 2 to 6 The extrusion mechanism 101 includes a heating cylinder 1, a relay hopper 2, a storage hopper 3, a heat 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 heating cylinder 1 has a nozzle 11 at its outlet end, which faces the printing platform 103, allowing the molten printing material extruded from the nozzle 11 to be stacked layer by layer on the printing platform 103. A heating element 12 is provided on the outer periphery of the heating cylinder 1 to heat the granular material entering the heating cylinder 1, causing the granular material to melt and be extruded from the nozzle 11. The inlet end of the heating cylinder 1 is connected to the first outlet 21 of the relay hopper 2, allowing the granular material stored in the relay hopper 2 to enter the heating cylinder 1 for heating and melting. The heat insulation gasket 4 is positioned between the feed end of the heating cylinder 1 and the first discharge port 21 of the relay hopper 2 to prevent the heating cylinder 1 from directly contacting the relay hopper 2. This, to a certain extent, blocks the heat transfer from the heating cylinder 1 to the relay hopper 2, preventing the granular consumables in the relay hopper 2 from melting or weaving due to the heat generated by the heating cylinder 1. It also ensures that the granular consumables can smoothly enter the heating cylinder 1, ensuring that the extrusion mechanism 101 can perform printing operations normally. Furthermore, by designing the heat insulation gasket 4 in this way, the granular consumables first contact the heat insulation gasket before entering the heating cylinder 1 and / or enter the heating cylinder 1 via the screw rod 8. This avoids direct contact between the granular consumables and the heating cylinder 1, reducing the risk of premature melting of the granular consumables.

[0036] Preferably, the first through hole 41 of the heat insulation gasket 4 is set in the shape of an inverted frustum, so that the granular consumables in the relay hopper 2 can enter the heating cylinder 1 more smoothly, and are less likely to accumulate or block at the heat insulation gasket 4; at the same time, with the push assistance of the screw rod 8, the continuous and stable feeding of the granular consumables is ensured, thereby ensuring the continuity and uniformity of the molten printing consumables extruded by the nozzle 11. The heat insulation gasket 4 is sleeved on the feed end of the heating cylinder 1, so that the heat insulation gasket 4 covers the end of the feed end of the heating cylinder 1, thereby better preventing the heating cylinder 1 from contacting the granular consumables at the first outlet 21 of the relay hopper 2; specifically, the large-diameter end of the first through hole 41 of the heat insulation gasket 4 is set close to the first outlet 21 of the relay hopper 2, and correspondingly, the small-diameter end of the first through hole 41 is set close to the feed end of the heating cylinder 1, and the small diameter end of the first through hole 41 is... The radial end is formed with a first insertion hole 43, which is connected to the first through hole 41. The feed end of the heating cylinder 1 is inserted into the first insertion hole 43. This design helps to improve the positioning effect of the heat insulation gasket 4 and better prevent the heat insulation gasket 4 from being misaligned relative to the feed end of the heating cylinder 1 and / or the first discharge port 21 of the relay hopper 2 after installation. This ensures that the granular consumables can accurately enter the heating cylinder 1 and are less likely to accumulate or block at the junction of the heat insulation gasket 4 and the heating cylinder 1.

[0037] To better assist the screw rod 8 in feeding the granular consumable into the heating cylinder 1 and prevent the granular consumable from accumulating or clogging at the feed end of the heating cylinder 1, a first spiral groove group 42 is provided on the wall of the first through hole 41 of the heat insulation gasket 4. At the same time, a second spiral groove group 13 is provided on the inner wall of the heating cylinder 1 near its feed end, and the second spiral groove group 13 is matched and connected with the first spiral groove group 42. That is, one first spiral groove of the first spiral groove group 42 is connected with one second spiral groove of the second spiral groove group 13, so that the granular consumable can smoothly enter the heating cylinder 1 through the first spiral groove and the second spiral groove, thereby further ensuring the continuity and uniformity of the molten printing consumable extruded by the nozzle 11, and thus improving the printing quality.

[0038] Furthermore, a first step 431 is formed inside the first insertion hole 43 of the heat insulation gasket 4, and a second step 14 is formed on the feed end of the heating cylinder 1. When the heating cylinder 1 is inserted into the first insertion hole 43, the second step 14 and the first step 431 are engaged and connected. This design facilitates the assembly and disassembly of the heat insulation gasket 4 and the heating cylinder 1, and also helps to distribute the pressure at the connection between the two, reduce local stress concentration, and improve the heat insulation effect.

[0039] Furthermore, a first limiting part 432 is provided in the first insertion hole 43 of the heat insulation gasket 4, and a second limiting part 15 is provided on the feed end of the heating cylinder 1. When the heating cylinder 1 is inserted into the first insertion hole 43, the first limiting part 432 and the second limiting part 15 cooperate to restrict the rotation of the heat insulation gasket 4 relative to the heating cylinder 1. This design can prevent mistaken assembly of the heat insulation gasket 4 and the heating cylinder 1, and also ensure that the first spiral groove group 42 and the second spiral groove group 13 can be accurately connected to ensure the smooth entry of the granular consumable into the heating cylinder 1. Preferably, the first limiting part 432 is formed on the first step 431, and the second limiting part 15 is formed on the second step 14; wherein, one of the first limiting part 432 and the second limiting part 15 is a slot and the other is a protrusion. For example, in this embodiment, the first limiting part 432 is a slot and the second limiting part 15 is a protrusion.

[0040] Furthermore, the heat insulation gasket 4 has an annular groove 44 formed around the first through hole 41. The annular groove 44 extends circumferentially from the large-diameter end of the first through hole 41 to the small-diameter end of the first through hole 41. Simultaneously, a second insertion hole 24 is provided at the first discharge port 21 of the relay hopper 2. The second insertion hole 24 communicates with the first discharge port 21 and is located between the bottom of the relay hopper 2 and the first discharge port 21. During assembly, the pressure ring 5 is installed in the annular groove 44 of the heat insulation gasket 4 and inserted into the second insertion hole 24 of the relay hopper 2. A limiting ring 16 is formed on the outer periphery of the heating cylinder 1, and the limiting ring 16 is located near the feed end of the heating cylinder 1. The clamping plate 6 is provided with a second through hole. When the heating cylinder 1 is assembled with the clamping plate 6, the heating cylinder 1 passes through the second through hole, and the clamping plate 6 is located between the limiting ring 16 and the nozzle 11. When the clamping plate 6 is assembled with the relay hopper 2, the clamping plate 6 and the relay hopper 2 are connected by the locking assembly 7, so that the clamping plate 6 is fixed on the relay hopper 2. At the same time, the clamping plate 6 pushes the limiting ring 16, forcing the heating cylinder 1, the heat insulation gasket 4 and the pressure ring 5 to move towards the relay hopper 2. Then, the pressure ring 5 cooperates with the limiting ring 16 to clamp and fix the heat insulation gasket 4, the heat insulation gasket 4 cooperates with the relay hopper 2 to fix the pressure ring 5, and the clamping plate 6 cooperates with the relay hopper 2 to fix the heating cylinder 1, the heat insulation gasket 4 and the pressure ring 5. As can be seen, with the cooperation of the pressure ring 5, clamping plate 6, locking assembly 7, heating cylinder 1, and relay hopper 2, the heat insulation gasket 4 can be reliably clamped and fixed. Furthermore, the annular groove 44 of the pressure ring 5, in conjunction with the heat insulation gasket 4, prevents the large-diameter end of the first through hole 41 of the heat insulation gasket 4 from deforming due to pressure, thereby preventing misalignment between the large-diameter end and the first outlet 21 of the relay hopper 2. This prevents leakage of the granular consumables and allows the granular consumables to smoothly pass through the heat insulation gasket 4 into the heating cylinder 1. Preferably, the heat insulation gasket 4 is made of polytetrafluoroethylene (PTFE) to provide excellent heat insulation performance, ensuring that the granular consumables in the relay hopper 2 do not melt.

[0041] Preferably, the relay hopper 2 is also provided with a heat dissipation grille 23, which can provide a certain ventilation and heat dissipation effect for the granular consumables in the relay hopper 2. Combined with the design of the heat insulation gasket 4, the temperature inside the relay hopper 2 is kept 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 inlet port 22 of the relay bin 2, so that the granular consumables in the storage bin 3 can be successively fed into the relay bin 2 for preheating and pushed into the heating cylinder 1 by the screw rod 8.

[0043] The screw rod 8 is located inside the heating cylinder 1 and the relay hopper 2. The screw rod 8 is connected to the output shaft of the motor, enabling the motor to drive the screw rod 8 to rotate, thereby pushing the granular consumables in the relay hopper 2 into the heating cylinder 1 for heating and melting. The motor is preferably installed on the relay hopper 2 and located outside the relay hopper 2, and the motor is preferably a stepper motor to achieve precise feeding of the granular consumables.

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

[0045] The heat dissipation module 9 includes a cooling fan 91 and an airflow channel 92. The cooling fan 91 is located at the air inlet of the airflow channel 92, and the air outlet of the airflow channel 92 is directed towards the extrusion end of the nozzle 11. The heat dissipation module 9 is used to cool the extruded printing filament, enabling rapid cooling of the extruded printing filament, ensuring the stability of the stacking and forming of the printing filament, and guaranteeing the forming quality of the printed 3D product.

[0046] The table below shows a comparison of relevant experimental data after using the heat insulation gasket 4 provided by this utility model.

[0047]

[0048] In summary, by designing the extrusion mechanism 101 of the particle 3D printer 100, the problem of the heating cylinder 1 being blocked by the melting of the particle consumables in the relay hopper 2 during the printing operation of the particle 3D printer 100 is prevented. This ensures that the screw rod 8 can reliably feed the heating cylinder 1 and prevent the heating cylinder 1 from being blocked, and ensures that the nozzle 11 can stably and normally extrude the molten printing consumables.

[0049] Finally, it should be emphasized that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An extrusion mechanism, including: A heating cylinder, wherein the discharge end of the heating cylinder is provided with a nozzle; A relay hopper, wherein the first discharge port of the relay hopper is connected to the inlet end of the heating cylinder; A storage bin, wherein the second discharge port of the storage bin is connected to the first inlet of the relay bin; A screw rod, wherein the screw rod is disposed within the heating cylinder and the relay hopper; An electric motor, wherein the output shaft of the electric motor is connected to the screw rod; Its features are: The extrusion mechanism also includes a heat insulation gasket, which is disposed 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 insulation gasket is in the shape of an inverted frustum. The heat insulation gasket is sleeved on the feed end. The large diameter end of the first through hole is close to the first discharge port. The hole wall of the first through hole is provided with a first spiral groove group. The heating cylinder has a second spiral groove group on its inner wall near the feed end, 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 heat insulation gasket has a first insertion hole formed at the small diameter end near the first through hole, which communicates with the first through hole, and a first limiting part is provided in the first insertion hole; The feed end is inserted into the first insertion hole, and the feed end is provided with a second limiting part. The second limiting part cooperates with the first limiting part to restrict the relative rotation of the heat insulation gasket and the heating cylinder.

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

5. The extrusion mechanism according to claim 3, characterized in that: The extrusion mechanism further includes: The pressure ring has an annular groove formed around the first through hole, and a second insertion hole is provided at the first discharge port. The pressure ring is installed in the annular groove and inserted into the second insertion hole. A clamping plate having a second through hole, a heating cylinder passing through the second through hole, and a limiting ring formed on the outer periphery of the heating cylinder, the limiting ring being connected between the heat insulation pad and the clamping plate; A locking assembly that connects the clamping plate and the relay hopper.

6. The extrusion mechanism according to claim 1, characterized in that: The screw has a mandrel and helical blades. The mandrel 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 helical blades are spirally wound around the mandrel.

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

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

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

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

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