Multi-material switching mechanism for 3D printer, multi-material switching method and 3D printer

Abstract

The application relates to the technical field of 3D printers, and provides a 3D printer multi-material switching mechanism, a 3D printer multi-material switching method and a 3D printer, which comprise a base and a base cover plate, the base cover plate is provided with a first discharge port, the base is provided with a bottom plate, the bottom plate is provided with at least two consumable feeding and discharging mechanisms, the consumable feeding and discharging mechanism comprises a consumable box body, a feeding transmission assembly, a discharging transmission assembly and a driving device, the driving device is used for driving the feeding transmission assembly and the discharging transmission assembly or directly driving the feeding transmission assembly, and the bottom plate is further provided with a switching device, under the action of the switching device, the feeding hole of the feeding transmission mechanism is corresponded to the feeding hole of the hot end nozzle.

Description

3D printer multi-material switching mechanism, multi-material switching method and 3D printer Technical Field

[0001] The present invention relates to the technical field of 3D printers, and in particular to a 3D printer multi-material switching mechanism, a multi-material switching method and a 3D printer. Background Art

[0002] Fused Deposition Manufacturing (FDM), also known as fused filament deposition, uses hot-melt materials, such as ABS, as raw materials. The material is fed to the nozzle by friction between a feed wheel and a driven wheel. A material guide tube is located between the nozzle and the feed wheel to ensure smooth and accurate material delivery to the nozzle. A resistive wire heater is located at the front of the nozzle, which heats and melts the material. The material is then extruded through the nozzle and coated onto the work platform, forming a cross-section. The platform then descends a certain distance, and the nozzle repeats the above process according to computer instructions, spraying the next cross-section until a solid object is printed. Current FDM fused deposition modeling 3D printers are mostly single-material / single-color, which cannot meet users' demand for diverse printed workpieces. Current multi-color 3D printers are typically equipped with multiple extrusion motors and multiple extrusion nozzles, placing multiple material trays side by side, which requires a large amount of space. Multiple nozzles are prone to overflow and can contaminate printed workpieces. Summary of the Invention

[0003] In order to solve the above problems, the present invention provides the following technical solutions:

[0004] The present invention provides a multi-material switching mechanism for a 3D printer, comprising a base and a base cover, wherein the base cover is provided with a first discharge port, a bottom plate is provided in the base, and at least two consumable material feeding and withdrawing mechanisms are provided on the bottom plate. The consumable material feeding and withdrawing mechanisms comprise a consumable material box, a feed transmission assembly, a return transmission assembly, and a driving device. The driving device is used to drive the feed transmission assembly and the return transmission assembly or directly drive the feed transmission assembly. A switching device is also provided on the bottom plate, and under the action of the switching device, the discharge hole of the feed transmission mechanism is aligned with the feed hole of the hot end nozzle.

[0005] Furthermore, the consumable box body is provided with a plurality of material reels and a plurality of consumable openings, and the consumable outlet of the consumable box body is connected to the corresponding feed transmission assembly through a hose, and the hose is a Teflon tube.

[0006] Furthermore, the feed transmission assembly includes a third gear and a fourth gear, the third gear and the fourth gear are meshed, the driving device includes a motor, a first gear is provided on the driving shaft of the motor, and the first gear is meshed with the third gear;

[0007] Or the feed transmission assembly further includes a second gear, a placement hole is provided at the center of the second gear, a connecting shaft is provided in the placement hole, the third gear is fixed on the connecting shaft, the third gear is meshed with the fourth gear, and the second gear is meshed with the first gear;

[0008] The material unloading transmission assembly includes a fifth gear, a worm, a worm wheel, a rotating shaft and a one-way bearing, the fifth gear is meshed with the second gear, the worm is arranged on the fifth gear, the worm wheel and the one-way bearing are both arranged on the rotating shaft, and the worm and worm wheel are meshed;

[0009] Or the material return transmission assembly only includes one motor.

[0010] Furthermore, the switching device is a motor with a unidirectional motion gear, and the motor is engaged with the bottom plate or the consumable material feeding and withdrawing mechanism to drive the consumable material feeding and withdrawing mechanism to rotate;

[0011] Or the switching device includes an electromagnetic coil and / or a permanent magnet, the electromagnetic coil is wound on the bottom of each consumable material feeding and withdrawing mechanism, and the bottom or side of the bottom plate is provided with an electromagnetic coil or permanent magnet that cooperates therewith;

[0012] Or the switching device includes a tube selector, which includes a movable turntable, a shell and a second drive structure. The second drive structure is connected to a gear or a rubber wheel. Several discharge ports (tubes) pass through the movable turntable. The second drive structure drives the gear or rubber wheel to drive the movable turntable to rotate, so that the discharge hole of the feed transmission mechanism corresponds to the feed hole of the hot end nozzle.

[0013] Furthermore, the second driving structure includes an electromagnetic coil and / or a permanent magnet;

[0014] Or the second driving structure includes only one motor.

[0015] Furthermore, the movable turntable includes a fin, which includes a curved surface. During use, the tube selector and the hot end are driven by an XY transmission mechanism and move in the XY plane. When it is necessary to switch consumables, the transmission mechanism drives the tube selector to hit the striker fixed on the outer shell in a single direction, and the striker drives the turntable in the tube selector to rotate along the direction of the fin curved surface.

[0016] Furthermore, the curved surface of the fin is mirrored in a symmetrical orientation, and the firing pin of the tube selector is also mirrored in an opposite orientation, thereby realizing bidirectional rotation of the tube selector turntable. If it needs to rotate in one direction, it hits the firing pin on the left, and if it needs to rotate in the other direction, it hits the firing pin on the right.

[0017] Multiple strikers can be set to achieve the shortest distance material change rotation (the movement distance required by the XY transmission mechanism is short). Multiple fins can be set. According to the number of tubes N, M*N fins can be set, where M is greater than or equal to 1. When M is greater than 2, multiple strikes are required to rotate the tube into place.

[0018] Furthermore, the tubes can be distributed on only one side of the turntable;

[0019] The movable turntable is provided with a physical limit device, or the movable turntable is provided with an encoder or other angle position sensing component for electronic limit.

[0020] Furthermore, a corresponding elastic limiting device is provided on the outer shell of the tube selector to prevent the tube selector from accidentally rotating and causing abnormal material extrusion when the XY movement has not yet hit the firing pin switch; the elastic limiting device can be an elastic member with a smooth top surface installed perpendicular to the turntable plane close to or close to the fin and can move up and down. When the position is normally limited, the elastic member is pushed upward by the spring to clamp the fin. When switching is required, external force causes the tube selector turntable to rotate to press the elastic member downward. After the switching is completed, there should be no interference above the elastic member, so it continues to push up and clamp the fin.

[0021] Furthermore, there are N tubes on the tube selector's tube turntable, and K feed ports at the hot end, where K is greater than or equal to 1. The K feed ports converge into a channel in the hot end leading to a mixing chamber, where the plastic in the mixing chamber can be heated and melted. By adjusting whether the N tubes are feeding and the corresponding feed rates of the K feed ports, precise color mixing or color change printing with higher switching efficiency can be achieved.

[0022] Furthermore, a movable cutter is provided at the top of the tube selector near the striker. When changing materials, the cutter hits the striker and cuts off the consumables on the top of the tube selector, which can save the time required for returning and feeding materials and improve reliability.

[0023] Furthermore, movable cutters are provided on both sides of the top of the tube selector near the striker. When changing materials, the cutters hit the striker and cut off the consumables on the top of the tube selector, which can save the time of changing materials.

[0024] Alternatively, a movable cutter is provided at the top of the discharge port of the feed and return assembly. When the material is changed at the outlet of the feed and return assembly, the movable cutter hits the striker and cuts off the top consumable material, which can save the material change time.

[0025] Alternatively, the movable cutter is set at any position between the discharge port of the feed and discharge assembly and the feed hole of the hot end nozzle, and cuts at the outlet of the feed and discharge assembly and when changing materials.

[0026] The present invention provides a 3D printing multi-material switching method, the switching method comprising:

[0027] The first step is to determine whether to switch or to prompt the user that there is no suitable consumable or the consumable is exhausted;

[0028] In the second step, if the first step is correct, the first extruder motor will retract the filament currently at the nozzle, pass through the first extruder gear, and move to the side of the first extruder gear away from the nozzle;

[0029] In the second step, the second extrusion motor retracts the filament currently near the first extrusion gear to the side of the second extrusion gear close to the nozzle;

[0030] Step 3: The feeding and withdrawing mechanism rotates to N positions, where N>=0 and N is an integer;

[0031] Step 4: After the second step is completed and the inspection is completed, the second extrusion motor will feed the filament currently near the first extrusion gear into the nozzle.

[0032] The present invention provides a 3D printer, comprising the switching mechanism described above.

[0033] The present invention has the following beneficial effects:

[0034] (1) The present invention distributes the consumable material feeding and withdrawing mechanisms evenly around the bottom plate, which can effectively save space. By providing multiple consumable material feeding and withdrawing mechanisms and a first discharge port, multi-color single feeding and single discharge can be achieved, thereby improving the utilization rate of the first discharge port;

[0035] (2) The switching device of the present invention is a motor with a unidirectional motion gear, which drives the consumables feeding and withdrawing mechanism to rotate by engaging with the base plate or the consumables feeding and withdrawing mechanism. It can also be a magnetic coil and / or permanent magnet, which generates electromagnetic force by applying alternating current, thereby driving the consumables feeding and withdrawing mechanism to rotate, ensuring that the consumables feeding and withdrawing mechanism can accurately rotate to the first discharge port. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is a simple schematic diagram of the switching mechanism of the present invention.

[0037] FIG2 is a simple schematic diagram of the switching device of the present invention.

[0038] FIG3 is a simple schematic diagram of the movable turntable of the present invention.

[0039] FIG4 is a simplified schematic diagram of the fin of the present invention.

[0040] FIG5 is a simple schematic diagram of a switching device with fins according to the present invention. DETAILED DESCRIPTION

[0041] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be pointed out that the embodiments are only specific explanations of the invention and should not be regarded as limitations of the invention. The purpose of the embodiments is to enable those skilled in the art to better understand and reproduce the technical solutions of the present invention. The scope of protection of the present invention shall still be based on the scope defined by the claims.

[0042] The present invention provides a multi-material switching mechanism for a 3D printer, comprising a base and a base cover, wherein the base cover is provided with a first discharge port, a bottom plate is provided inside the base, and at least two consumable material feeding and withdrawing mechanisms are provided on the bottom plate. The consumable material feeding and withdrawing mechanisms comprise a consumable material box, a feed transmission assembly, a return transmission assembly, and a drive device, wherein the drive device is used to drive the feed transmission assembly and the return transmission assembly or directly drive the feed transmission assembly. A switching device is also provided on the bottom plate, and under the action of the switching device, the discharge hole 7 of the feed transmission mechanism corresponds to the feed hole 9 of the hot end nozzle 10.

[0043] As shown in FIG1 , the consumable box body 2 is provided with multiple material reels 1 and multiple consumable openings 3 . The consumable outlets of the consumable box body 2 are connected to corresponding feed transmission components 6 through hoses 4 , and the hoses 4 are Teflon tubes.

[0044] In some preferred embodiments, the feed transmission assembly includes a third gear and a fourth gear, the third gear and the fourth gear are meshed, the drive device includes a motor, a first gear is provided on the drive shaft of the motor, and the first gear is meshed with the third gear;

[0045] Or the feed transmission assembly further includes a second gear, a placement hole is provided at the center of the second gear, a connecting shaft is provided in the placement hole, the third gear is fixed on the connecting shaft, the third gear is meshed with the fourth gear, and the second gear is meshed with the first gear;

[0046] The material unloading transmission assembly includes a fifth gear, a worm, a worm wheel, a rotating shaft and a one-way bearing, the fifth gear is meshed with the second gear, the worm is arranged on the fifth gear, the worm wheel and the one-way bearing are both arranged on the rotating shaft, and the worm and worm wheel are meshed;

[0047] Or the material return transmission assembly only includes one motor.

[0048] In some preferred embodiments, the switching device is a motor with a unidirectional motion gear, and the motor is engaged with the bottom plate or the consumable material feeding and withdrawing mechanism to drive the consumable material feeding and withdrawing mechanism to rotate;

[0049] Or the switching device includes an electromagnetic coil and / or a permanent magnet, the electromagnetic coil is wound on the bottom of each consumable material feeding and withdrawing mechanism, and the bottom or side of the bottom plate is provided with an electromagnetic coil or permanent magnet that cooperates therewith;

[0050] As shown in Figure 2-3, the switching device includes a tube selector 999, which includes a movable turntable, a housing 999d, and a second drive structure 999a. The second drive structure 999a is connected to a gear or rubber wheel. Several discharge ports (tubes) pass through the movable turntable. The second drive structure drives the gear or rubber wheel 999c to drive the movable turntable to rotate, so that the discharge hole 991b of the feed transmission mechanism corresponds to the feed hole 8 of the hot end nozzle. At this time, the consumable box 2, the return transmission assembly, and the feed transmission assembly, but they do not rotate.

[0051] In some preferred embodiments, the second driving structure includes an electromagnetic coil and / or a permanent magnet;

[0052] Or the second driving structure includes only one motor.

[0053] As shown in FIG4-5, the movable turntable includes a fin 999c (1), which includes a curved surface. During use, the tube selector and the hot end are driven by an XY transmission mechanism 91 and move in the XY plane. When it is necessary to switch consumables, the transmission mechanism drives the tube selector to strike the striker 998 fixed to the housing 90 in a single direction. The striker 998 drives the turntable in the tube selector to rotate along the direction of the fin curved surface.

[0054] In some preferred embodiments, the curved surface of the fin is mirrored in a symmetrical orientation (e.g., 999c(2)), and the firing pin of the tube selector is also mirrored in an opposite orientation, thereby realizing bidirectional rotation of the tube selector turntable. If the turntable needs to rotate in one direction, the firing pin on the left is struck; if the turntable needs to rotate in the other direction, the firing pin on the right is struck.

[0055] Multiple strikers can be set to achieve the shortest distance material change rotation (the movement distance required by the XY transmission mechanism is short). Multiple fins can be set. According to the number of tubes N, M*N fins can be set, where M is greater than or equal to 1. When M is greater than 2, multiple strikes are required to rotate the tube into place.

[0056] In some preferred embodiments, the tubes may be distributed on only one side of the turntable;

[0057] The movable turntable is provided with a physical limit device, or the movable turntable is provided with an encoder or other angle position sensing component for electronic limit.

[0058] In some preferred schemes, there is a corresponding elastic limit device on the tube selector housing to prevent the tube selector from accidentally rotating and causing abnormal material extrusion when the XY movement has not yet hit the firing pin switch; the elastic limit device can be an elastic member with a smooth top surface installed perpendicular to the turntable plane close to or close to the fin and can move up and down. When normally limited, the elastic member is pushed upward by the spring to clamp the fin. When switching is required, external force causes the tube selector turntable to rotate to press the elastic member downward. After the switching is completed, there should be no interference above the elastic member, so it continues to push up and clamp the fin.

[0059] In some preferred embodiments, there are N tubes on the tube selector tube turntable, and there are K feed ports at the hot end, where K is greater than or equal to 1. The K feed ports converge into a channel in the hot end leading to a mixing chamber, and the plastic in the mixing chamber can be heated and melted; by adjusting whether the N tubes are feeding and the corresponding feed rates of the K feed ports, precise color mixing or color change printing with higher switching efficiency can be achieved.

[0060] In some preferred embodiments, a movable cutter is provided at the top of the tube selector near the striker. When changing materials, the cutter hits the striker and cuts off the consumables at the top of the tube selector, which can save the time required for returning and feeding materials and improve reliability.

[0061] In some preferred embodiments, movable cutters are provided on both sides of the top of the tube selector near the striker. When reloading, the cutters strike the striker and cut off the consumables on the top of the tube selector, thereby saving reloading time.

[0062] Alternatively, a movable cutter is provided at the top of the discharge port of the feed and return assembly. When the material is changed at the outlet of the feed and return assembly, the movable cutter hits the striker and cuts off the top consumable material, which can save the material change time.

[0063] Alternatively, the movable cutter is set at any position between the discharge port of the feed and discharge assembly and the feed hole of the hot end nozzle, and cuts at the outlet of the feed and discharge assembly and when changing materials.

[0064] The present invention provides a 3D printing multi-material switching method, the switching method comprising:

[0065] The first step is to determine whether to switch or to prompt the user that there are no suitable consumables or the consumables are exhausted.

[0066] In the second step, if the first step is correct, the first extruder motor will retract the filament currently at the nozzle, pass through the first extruder gear, and move to the side of the first extruder gear away from the nozzle;

[0067] In the second step, the second extrusion motor retracts the filament currently near the first extrusion gear to the side of the second extrusion gear close to the nozzle;

[0068] Step 3: The feeding and withdrawing mechanism rotates to N positions, where N>=0 and N is an integer;

[0069] Step 4: After the second step is completed and the inspection is completed, the second extrusion motor will feed the filament currently near the first extrusion gear into the nozzle.

[0070] The present invention provides a 3D printer, comprising the switching mechanism described above.

[0071] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

Claims

1. 3D printer multi-material switching mechanism, characterized in that: It includes a base and a base cover plate, the base cover plate is provided with a first discharge port, the base is provided with a bottom plate, the bottom plate is provided with at least two consumable material feeding and withdrawing mechanisms, the consumable material feeding and withdrawing mechanisms include a consumable material box body, a feeding transmission assembly, a withdrawing transmission assembly and a driving device, the driving device is used to drive the feeding transmission assembly and the withdrawing transmission assembly or directly drive the feeding transmission assembly, and the bottom plate is also provided with a switching device, under the action of the switching device, the discharge hole of the feeding transmission mechanism corresponds to the feeding hole of the hot end nozzle.

2. The 3D printer multi-material switching mechanism according to claim 1, characterized in that: The consumable box body is provided with a plurality of material reels and a plurality of consumable openings. The consumable outlet of the consumable box body is connected to the corresponding feed transmission assembly through a hose, and the hose is a Teflon tube.

3. The 3D printer multi-material switching mechanism according to claim 1, characterized in that: The feed transmission assembly includes a third gear and a fourth gear, the third gear and the fourth gear are meshed, the drive device includes a motor, a first gear is provided on the drive shaft of the motor, and the first gear is meshed with the third gear; Or the feed transmission assembly further includes a second gear, a placement hole is provided at the center of the second gear, a connecting shaft is provided in the placement hole, the third gear is fixed on the connecting shaft, the third gear is meshed with the fourth gear, and the second gear is meshed with the first gear; The material-returning transmission assembly comprises a fifth gear, a worm, a worm wheel, a rotating shaft and a one-way bearing, wherein the fifth gear is meshed with the second gear, the worm is arranged on the fifth gear, the worm wheel and the one-way bearing are both arranged on the rotating shaft, and the worm is meshed with the worm wheel; Or the material-returning transmission assembly includes only one motor.

4. The 3D printer multi-material switching mechanism according to claim 1, characterized in that: The switching device is a motor with a unidirectional motion gear, and the motor is meshed with the bottom plate or the consumable material feeding and withdrawing mechanism to drive the consumable material feeding and withdrawing mechanism to rotate; Or the switching device includes an electromagnetic coil and / or a permanent magnet, the electromagnetic coil is wound around the bottom of each consumable material feeding and withdrawing mechanism, and the bottom or side of the bottom plate is provided with an electromagnetic coil or a permanent magnet that matches it; Or the switching device includes a tube selector, which includes a movable turntable, a shell and a second driving structure, the second driving structure is connected to a gear or a rubber wheel, and a plurality of discharge ports (tubes) pass through the movable turntable. The second driving structure drives the gear or the rubber wheel to drive the movable turntable to rotate, so that the discharge hole of the feed transmission mechanism corresponds to the feed hole of the hot end nozzle.

5. The 3D printer multi-material switching mechanism according to claim 4, characterized in that: The second driving structure includes an electromagnetic coil and / or a permanent magnet; Or the second driving structure includes only one motor.

6. The 3D printer multi-material switching mechanism according to claim 4, characterized in that: The movable turntable includes a fin, which includes a curved surface. During use, the tube selector and the hot end are driven by an XY transmission mechanism and move in the XY plane. When it is necessary to switch consumables, the transmission mechanism drives the tube selector to hit a striker fixed on the shell in a single direction, and the striker drives the turntable in the tube selector to rotate along the direction of the fin curved surface.

7. The 3D printer multi-material switching mechanism according to claim 4, characterized in that: The curved surface of the fin is mirrored in a symmetrical orientation, and the striker is also mirrored in the opposite orientation of the tube selector, so that the bidirectional rotation of the tube selector turntable is realized. If it needs to rotate in one direction, it hits the striker on the left, and if it needs to rotate in the other direction, it hits the striker on the right; Multiple strikers can be provided to achieve the shortest distance of material replacement rotation (the movement distance required by the XY transmission mechanism is short). Multiple fins can be provided. According to the number of tubes N, M*N fins can be provided, where M is greater than or equal to 1. When M is greater than 2, multiple strikes are required to rotate the tube into place.

8. The 3D printer multi-material switching mechanism according to claim 4, characterized in that: The tubes can be distributed on only one side of the turntable; The movable turntable is provided with a physical limit device, or the movable turntable is provided with an encoder or other angle position sensing component for electronic limit.

9. The 3D printer multi-material switching mechanism according to claim 1, characterized in that: There is a corresponding elastic limit device on the tube selector housing to prevent the tube selector from accidentally rotating when the XY movement has not hit the firing pin to switch, causing abnormal material extrusion; the elastic limit device can be an elastic part with a smooth top that is installed perpendicular to the turntable plane close to or close to the fin and can move up and down. When normally limited, the elastic part is pushed up by the spring to clamp the fin. When switching is required, external force causes the tube selector turntable to rotate to press the elastic part down. After the switching is completed, there should be no interference above the elastic part, so it continues to push up and clamp the fin.

10. The 3D printer multi-material switching mechanism according to claim 1, characterized in that: There are N tubes on the tube turntable of the tube selector, and there are K feed ports at the hot end, where K is greater than or equal to 1. The K feed ports are gathered into a channel in the hot end leading to a mixing chamber, and the plastic in the mixing chamber can be heated and melted; by adjusting whether the N tubes are fed and the corresponding feed rates of the K feed ports, accurate color mixing or color change printing with higher switching efficiency can be achieved.

11. The 3D printer multi-material switching mechanism according to claim 1, characterized in that: A movable cutter is arranged near the striker at the top of the tube selector. When changing materials, the cutter hits the striker to cut off the consumables at the top of the tube selector, which can save the time required for changing materials during material withdrawal and feeding and improve reliability.

12. The 3D printer multi-material switching mechanism according to claim 1, characterized in that: There are movable cutters on both sides of the top of the tube selector near the striker. When changing materials, the cutters hit the striker and cut off the consumables on the top of the tube selector, which can save the time of changing materials. Alternatively, the movable cutter is arranged at the top of the outlet of the feed and withdraw assembly. When the outlet of the feed and withdraw assembly is changing materials, the movable cutter hits the striker to cut off the top consumables, thereby saving the time of changing materials. Alternatively, the movable cutter is arranged at any position from the discharge port of the feed and discharge assembly to the feed hole of the hot end nozzle, and cuts at the outlet of the feed and discharge assembly and when changing materials.

13. A 3D printing multi-material switching method, characterized in that: The switching method is applicable to the switching mechanism described in any one of claims 1 to 12, and the switching method comprises: The first step is to determine whether to switch or to prompt the user that there is no suitable consumable or the consumable is exhausted; In the second step, if the first step is correct, the first extruder motor will retract the filament currently at the nozzle, through the first extruder gear, to the side of the first extruder gear away from the nozzle; In the second step, the second extruder motor moves the filament currently near the first extruder gear back to the second extruder gear near the nozzle side; Step 3: The feeding and withdrawing mechanism rotates to N positions, where N>=0 and N is an integer; Step 4: After the second step is completed and the inspection is completed, the second extrusion motor feeds the filament currently near the first extrusion gear into the nozzle.

14. A 3D printer, characterized in that: It comprises the switching mechanism described in any one of claims 1-12.

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