A material feeding and withdrawing device and material feeding and withdrawing method for a 3D printer

Abstract

The present invention discloses a material feeding and unloading device and a material feeding and unloading method for a 3D printer. The material feeding and unloading device includes a feeding assembly, an unloading assembly, and a switching assembly. The feeding assembly includes a feeding gear for conveying printing wire, and the unloading assembly includes an unloading gear for driving a material tray to rotate; the switching assembly includes a driving gear, a transmission shaft, a first reversing arm, and a motor. The motor drives the transmission shaft to rotate, the driving gear is fixed to the transmission shaft, the first reversing arm is rotatably sleeved on the transmission shaft, and the first and second driven gears are respectively installed at both ends of the first reversing arm. The first reversing arm is magnetically connected to the driving gear and can rotate clockwise or counterclockwise with the driving gear; when the first reversing arm rotates, the first driven gear can approach the feeding gear and mesh with it for transmission, or the second driven gear can approach the unloading gear and mesh with it for transmission. A material feeding and unloading method for a 3D printer adopts the above-mentioned material feeding and unloading device to realize transmission position switching and can also effectively improve the problem of wear and failure.

Description

Technical Field

[0001] The present invention belongs to the technical field of printers, and in particular relates to a material feeding and withdrawing device and a material feeding and withdrawing method of a 3D printer. Background Art

[0002] 3D printing, short for 3 Dimensional Printing, is a type of additive manufacturing technology. It uses software-controlled layered manufacturing based on three-dimensional computer models. 3D printing is typically implemented using digital printers. 3D printers can be used in any industry, with widespread applications in healthcare, construction, automotive, aerospace, and education.

[0003] FDM 3D printers often need to continuously feed and unfeed materials when achieving multi-color printing. The force positions of feeding and unfeeding are often different. Feeding is achieved by pressing the filament filament with gears to push it, but unfeeding is different. The filament tray needs to be rotated to unfeed the filament to prevent the filament from becoming loose and tangled. In the existing technology, friction is often used to switch the transmission position. However, the two components rubbing against each other will inevitably wear out after the long-term rotation and friction of the motor, eventually causing functional failure.

[0004] Therefore, a new technology is needed to solve the problem of wear and failure when switching the transmission position through friction in the existing technology. Summary of the Invention

[0005] To solve the above problems in the prior art, the present invention provides a material feeding and withdrawing device and method for a 3D printer, which uses attractive magnets to achieve switching of transmission positions, and can effectively improve the problem of wear and failure.

[0006] The present invention adopts the following technical solutions:

[0007] A feeding and withdrawing device for a 3D printer, comprising a bracket and a feeding assembly and a switching assembly mounted on the bracket, wherein the feeding assembly comprises a feeding gear for conveying printing wire to a feeding channel;

[0008] The switching assembly includes a driving gear, a transmission shaft, a first reversing arm, and a motor. The motor is used to drive the transmission shaft to rotate. The driving gear is fixed to the transmission shaft. The middle portion of the first reversing arm is rotatably mounted on the transmission shaft. The first and second driven gears are rotatably mounted on both ends of the first reversing arm. The first reversing arm is magnetically connected to the driving gear and can rotate clockwise or counterclockwise with the driving gear.

[0009] When the first reversing arm rotates, the first driven gear can approach the feed gear and be connected to it, or the second driven gear can approach the material tray and mesh with it for transmission. The second driven gear can unload the material when driving the material tray to rotate.

[0010] As a further improvement of the technical solution of the present invention, the switching assembly also includes a magnetic module, which includes a first magnet and a second magnet that can attract each other, the second magnet is arranged on the driving gear, and the first magnet is arranged on the first reversing arm.

[0011] As a further improvement to the technical solution of the present invention, the transmission shaft includes a first section and a second section that are coaxial and fixedly connected to each other, the end of the first section away from the second section is rotatably connected to the motor, the diameter of the first section is larger than the diameter of the second section, the first section forms a step surface on the end surface connected to the second section, the driving gear is detachably mounted on the second section and can abut against the step surface; the first reversing arm is rotatably mounted on the first section;

[0012] The first magnet is mounted on a side of the first reversing arm close to the driving gear, and the second magnet is mounted on a side of the driving gear close to the first reversing arm;

[0013] The second magnet is provided with a mounting groove, the notch of the mounting groove is facing the direction of the first magnet, and a plurality of steel balls are provided in the mounting groove, each of the steel balls partially protrudes from the mounting groove, and the centers of the plurality of steel balls are located in a plane perpendicular to the transmission shaft.

[0014] As a further improvement of the technical solution of the present invention, the switching assembly also includes a second reversing arm, which is rotatably mounted on the second section. The driving gear is located between the first reversing arm and the second reversing arm, and both ends of the first driven gear and the second driven gear are respectively rotatably connected to the first reversing arm and the second reversing arm.

[0015] As a further improvement of the technical solution of the present invention, a second center hole and a third step hole that are coaxial and interconnected are provided in the middle of the second reversing arm. The second center hole and the third step hole can both allow the second section to pass through. A second bearing is installed between the second reversing arm and the second section, and the second bearing is located in the third step hole; the third step hole is located on the end of the second reversing arm away from the driving gear.

[0016] As a further improvement to the technical solution of the present invention, a first central hole is provided in the middle of the first reversing arm for the first section to pass through, and a first stepped hole and a second stepped hole are provided at both ends of the first central hole, each having a diameter larger than that of the first central hole, and the first stepped hole and the second stepped hole are coaxial with the first central hole and communicate with each other;

[0017] A first bearing is installed between the first reversing arm and the first section. The first bearing is installed in the first step hole. The first magnet is installed in the second step hole.

[0018] As a further improvement of the technical solution of the present invention, the first and second reversing arms are respectively provided with a first through hole and a second through hole at both ends, and the centers of the first driven gear and the second driven gear are respectively provided with a central axis. The central axes at both ends of the first driven gear can be rotatably inserted into the two first through holes, and the central axes at both ends of the second driven gear can be rotatably inserted into the two second through holes.

[0019] As a further improvement of the technical solution of the present invention, a retaining spring is detachably installed on the transmission shaft, and a slot for installing the retaining spring is provided on the side of the first section. The second reversing arm, the driving gear, and the first reversing arm are all located between the slot and the motor.

[0020] As a further improvement of the technical solution of the present invention, the feeding assembly further includes a passive wheel, which is fixed on the feeding channel, and the passive wheel and the feeding gear jointly compress the printing wire and convey the printing wire along the feeding channel;

[0021] A transmission gear is provided at the shaft end of the feed gear, the transmission gear is coaxially arranged with the feed gear and can rotate synchronously, and the transmission gear is used to mesh with the first driven gear for transmission;

[0022] The feeding assembly further includes a compression spring, and the compression spring is used to compress the feeding gear and the passive wheel;

[0023] The two ends of the feed channel are respectively provided with a feed port and a discharge port, and the discharge port is provided with a tubular claw for connecting a Teflon tube, and the Teflon tube is used to transport the printing wire to the next level device;

[0024] The feeding assembly further includes a consumables position detection mechanism for detecting the position of the printing wire;

[0025] A material feeding and withdrawing method for a 3D printer, using the material feeding and withdrawing device of the 3D printer as described above, wherein the support is provided with a first working station, a second working station, and a non-working station, the material feeding and withdrawing device further comprises a material withdrawing assembly, and the material withdrawing assembly comprises a material withdrawing gear;

[0026] The material feeding and withdrawing method comprises the following steps:

[0027] When the motor drives the transmission shaft to rotate counterclockwise, the first reversing arm follows the transmission shaft to rotate to the first working position, at which time the first driven gear is engaged with the feed gear for transmission, and the driving force of the motor is transmitted to the feed gear to realize feeding; when the motor drives the transmission shaft to rotate clockwise, the first reversing arm follows the transmission shaft to rotate to the second working position, at which time the second driven gear is engaged with the unloading gear for transmission, and the unloading gear rotates the material tray through the support roller to unload the material; when the first reversing arm can be rotated to the non-working position, at this time the first driven gear is not engaged with the feed gear for transmission, and the second driven gear is not engaged with the unloading gear for transmission; wherein, the support roller is engaged with the material tray.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] In this solution, the motor drives the transmission shaft to rotate through a transmission connection, the drive gear is mounted on the transmission shaft and radially fixed to the transmission shaft, the middle portion of the first reversing arm is rotatably mounted on the transmission shaft, and the first driven gear and the second driven gear are respectively mounted on the two ends of the first reversing arm. The first reversing arm is magnetically connected to the drive gear and can rotate clockwise or counterclockwise with the drive gear. When feeding is required, the motor drives the drive gear to rotate forward via the transmission shaft, the first reversing arm rotates with the drive gear and drives the first driven gear to gradually approach the feed gear until the first driven gear and the feed gear are connected and drive the feed gear to rotate, thereby achieving feeding. When withdrawing material, the motor drives the drive gear to rotate in the opposite direction via the transmission shaft, the first reversing arm rotates with the drive gear and drives the second driven gear to gradually approach the withdrawing gear until the second driven gear and the withdrawing gear are meshed and transmitted.

[0030] This solution uses attractive magnets to achieve switching of transmission positions, which can effectively improve the problem of wear and failure. The switching component realizes the position switching function through the magnetic connection between the first reversing arm and the driving gear. Different transmission directions are achieved through different position switching, so that a single motor can realize both transmission and switching functions at the same time. It has a simple structure and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The technology of the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0032] Figure 1 It is a structural schematic diagram of the reversing arm of the present invention when it rotates to the second working position;

[0033] Figure 2It is a structural schematic diagram of the reversing arm of the present invention when it rotates to the first working position;

[0034] Figure 3 It is a structural schematic diagram of the reversing arm of the present invention when it rotates to a non-working position;

[0035] Figure 4 It is a structural diagram of the feed assembly;

[0036] Figure 5 It is a schematic diagram of the connection structure between the feeding component, the motor and the bracket;

[0037] Figure 6 is an axonometric view of the switch component;

[0038] Figure 7 It is a structural diagram of the switching component;

[0039] Figure 8 yes Figure 7 Schematic diagram of the AA section structure;

[0040] Figure 9 It is a schematic diagram of the overall structure of the present invention;

[0041] Figure 10 This is a schematic structural diagram of the present invention in which the transmission shaft and the motor are connected via a transmission assembly and the second reversing arm is not provided;

[0042] Figure 11 It is the connection structure between the feed gear and the transmission gear.

[0043] Reference numerals:

[0044] 1-feed assembly; 11-transmission gear; 12-feed channel; 121-feed port; 122-discharge port; 13-passive wheel; 14-compression spring; 15-feed gear;

[0045] 2- material removal gear;

[0046] 3-Switching assembly; 31-Drive gear; 32-First reversing arm; 321-First through hole; 322-Second through hole; 33-Second reversing arm; 331-Second center hole; 332-Third step hole; 34-First driven gear; 35-Second driven gear; 36-Motor; 361-Transmission shaft; 362-Motor shaft; 3611-Second section; 3612-First section; 3613-Step surface; 37-First bearing; 38-Second bearing; 39-Circlip; 310-Magnetic module; 3101-First magnet; 3102-Second magnet;

[0047] 4-bracket; 41-first working station; 42-second working station;

[0048] 5-support roller;

[0049] 6-feeding tray;

[0050] 7- cabinet;

[0051] 8- transmission assembly; 81- helical gear; 82- worm;

[0052] 9-Steel ball. DETAILED DESCRIPTION

[0053] The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments and features in the embodiments of this application can be combined with each other unless there is a conflict. The same reference numerals used throughout the drawings indicate the same or similar parts.

[0054] It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature or indirectly fixed or connected to the other feature. Furthermore, terms such as "upper," "lower," "left," and "right" used in this disclosure are intended solely to describe the relative positions of the components of the disclosure as shown in the accompanying drawings.

[0055] Reference Figures 1 to 11 A feeding and unloading device for a 3D printer includes a bracket 4 and a feeding assembly 1, an unloading assembly, and a switching assembly 3 mounted on the bracket 4. The feeding assembly 1 includes a feeding gear 15 for conveying printing wire to the feeding channel 12 on the 3D printer. The switching assembly 3 includes a driving gear 31, a transmission shaft 361, a first reversing arm 32, and a motor 36. The motor 36 is used to drive the transmission shaft 361 to rotate. The driving gear 31 is mounted on the transmission shaft 361 and is radially fixed to the transmission shaft 361. The middle portion of the first reversing arm 32 is rotatably mounted on the transmission shaft 361. The first reversing arm 32 is linear, and a first driven gear 34 and a second driven gear 35 are mounted at both ends of the first reversing arm 32 respectively. The first reversing arm 32 is magnetically connected to the driving gear 31 and can rotate clockwise or counterclockwise with the driving gear 31. When the first reversing arm 32 rotates, the first driven gear 34 can approach the feed gear 15 and be connected to it to drive the feed gear 15 to rotate, or the second driven gear 35 can approach the material tray and mesh with it for transmission, and the driving gear 31 transmits the driving force for returning the material to the material tray 6 for returning the material, and the second driven gear 35 can drive the material tray 6 to rotate to return the material.

[0056] The output end of the motor 36 is provided with a motor shaft 362. The motor shaft 362 can be directly set as a transmission shaft 361, or the motor shaft 362 can be connected to the transmission shaft 361 through a transmission assembly 8 and can drive the transmission shaft 361 to rotate. At this time, the motor shaft 362 does not directly serve as the shaft carrying the switching assembly 3. The transmission assembly 8 includes a bevel gear 81 and a worm 82. The bevel gear 81 is fixed on the transmission shaft 361, and the worm 82 is set on the motor 36. The worm 82 is fixedly connected to the motor shaft 362, and the worm 82 can be interference fit with the motor shaft 362. The transmission connection between the transmission shaft 361 and the motor 36 is realized by the worm 82 and the bevel gear 81, and the power of the motor 36 is transmitted to the switching assembly 3 to realize feeding and withdrawing materials. The switching assembly 3 can be installed in a frame or a box 7. The motor shaft 362 passes through a side wall of the box 7 and is connected to the worm 82. The motor 36 is installed outside the box 7. The two ends of the transmission shaft 361 are respectively rotatably fixedly connected to the two opposite inner walls of the box 7. Figure 10 shown.

[0057] Specifically, a material stripping assembly can be provided to achieve meshing transmission between the second driven gear 35 and the material tray 6. The material stripping assembly includes a material stripping gear 2, which meshes with the material tray. When the material stripping gear 2 rotates, it can drive the material tray 6 to rotate to strip the material. During the rotation of the first reversing arm 32, the second driven gear 35 can approach the material stripping gear 2 and mesh with it. The driving gear 31 transmits the driving force for stripping the material through the material stripping gear 2 to the material tray 6 for stripping the material.

[0058] When the motor 36 is started, the motor shaft of the motor 36, i.e., the transmission shaft 361, can rotate forward or reverse. When feeding is required, the motor 36 drives the drive gear 31 to rotate forward via the transmission shaft 361. The first reversing arm 32 rotates with the drive gear 31 and drives the first driven gear 34 to gradually approach the feed gear 15 until the first driven gear 34 is connected to the feed gear 15 and can drive the feed gear to rotate. A gear structure that can rotate synchronously with the feed gear 15 can be coaxially fixed to the shaft end of the feed gear 15. The first driven gear 34 engages with this gear structure, thereby driving the feed gear 15 to rotate, thereby realizing a transmission connection between the first driven gear 34 and the feed gear 15. When unloading is required, the motor 36 drives the drive gear 31 to rotate in the opposite direction via the transmission shaft 361. The first reversing arm 32 rotates with the drive gear 31 and drives the second driven gear 35 to gradually approach the unloading gear 2 until the second driven gear 35 engages with the unloading gear 2 for transmission. The forward direction and the reverse direction are used to indicate that the rotation directions of the transmission shaft 361 are opposite.

[0059] This solution uses attractive magnets to achieve switching of transmission positions, which can effectively improve the problem of wear and failure. The switching component 3 realizes the position switching function through the magnetic connection between the first reversing arm 32 and the driving gear 31. Different transmission directions are achieved through different position switching, so that a single motor 36 can simultaneously realize both transmission and switching functions, with a simple structure and high reliability.

[0060] Specifically, the switching assembly 3 also includes a magnetic module 310, which includes a first magnet 3101 and a second magnet 3102 that can attract each other, the second magnet 3102 being arranged on the driving gear 31, and the first magnet 3101 being arranged on the first reversing arm 32. The driving gear 31 is connected to the first reversing arm 32 by the magnetic attraction of the first magnet 3101 and the second magnet 3102, so that the driving gear 31 can drive the first reversing arm 32 to rotate synchronously, wherein the magnetic attraction between the first magnet 3101 and the second magnet 3102 can be set according to actual conditions. The magnetic module 310 can be set to at least one magnet according to actual conditions, one of which can be installed on the driving gear 31, and the remaining one or more magnets can be installed on the first reversing arm 32.

[0061] Specifically, the transmission shaft 361 includes a first section 3612 and a second section 3611 that are coaxial and fixedly connected to each other. The end of the first section 3612, distal from the second section 3611, is rotatably connected to the main body of the motor 36. The diameter of the first section 3612 is larger than that of the second section 3611. The first section 3612 forms a stepped surface 3613 on the end surface connected to the second section 3611. The drive gear 31 is removably mounted on the second section 3611 and is capable of abutting against the stepped surface 3613. The drive gear 31 rotates synchronously with the second section 3611. A connecting hole is provided in the center of the drive gear 31 for insertion of the second section 3611. The first reversing arm 32 is located between the drive gear 31 and the motor 36. The first magnet 3101 is mounted on the side of the first reversing arm 32 that is close to the drive gear 31, and the second magnet 3102 is mounted on the side of the drive gear 31 that is close to the first reversing arm 32. The first reversing arm 32 is rotatably mounted on the first section 3612 and can rotate relative to the transmission shaft 361 after the first driven gear 34 is engaged with the feed gear 15 or the second driven gear 35 is engaged with the discharge gear 2. The first section 3612 has a circular radial cross-section, while the second section 3611 has a D-shaped radial cross-section. A connecting hole with a D-shaped radial cross-section is provided at the center of the drive gear 31. The second section 3611 can be inserted into and adapted to the connecting hole. The drive gear 31 is radially fixed to the second section 3611 of the transmission shaft 361 so that the drive gear 31 can rotate synchronously with the transmission shaft 361. The step surface 3613 can limit the movement of the drive gear 31 toward the motor 36.

[0062] Specifically, the second magnet 3102 is provided with a mounting groove, the notch of the mounting groove is oriented toward the first magnet 3101, and a plurality of steel balls 9 are provided in the mounting groove. The plurality of steel balls 9 can be mounted in the mounting groove by a mounting frame. The centers of the steel balls are all located on the same plane, which is perpendicular to the axis of the transmission shaft 361. Each steel ball 9 partially protrudes from the notch of the mounting groove and can contact the first magnet 3101. There is a distance between the first magnet 3101 and the second magnet 3102, and the distance is less than the diameter of the steel ball 9. By arranging a plurality of steel balls 9 between the two magnets, the distance between the first magnet 3101 and the second magnet 3102 can be kept fixed, so that the magnetic attraction torque remains unchanged, thereby avoiding fluctuations in the load of the motor 36. Among them, the structure of arranging a plurality of steel balls 9 between the two magnets in this solution has the same operating principle as a planar thrust bearing. The steel balls 9 and their mounting frame can be regarded as the steel ball retainer in the middle of the planar thrust bearing, and the two magnets serve as the races on both sides of the thrust ball bearing.

[0063] Specifically, when there is sufficient installation space, the switching assembly 3 further includes a second reversing arm 33, which is rotatably mounted on the second section 3611. The driving gear 31 is located between the first reversing arm 32 and the second reversing arm 33. Both ends of the first driven gear 34 and the second driven gear 35 are rotatably connected to the first reversing arm 32 and the second reversing arm 33, respectively. The first driven gear 34 and the second driven gear 35 are both located between the first reversing arm 32 and the second reversing arm 33. The relative meshing position of the first driven gear 34 and the second driven gear 35 on the driving gear 31 can be adjusted according to actual conditions or the positions of the unloading station and the feeding station. The axial lengths of the toothed portions of the driving gear 31, the first driven gear 34, and the second driven gear 35 can be set to be equal. In actual situations, in order to save some installation space, the second reversing arm 33 may not be provided. Conventional fixing means may be used to rotatably fix one end of the first driven gear 34 and the second driven gear 35 to the first reversing arm 32. The spacing between the first magnet 3101 and the second magnet 3102 may be positioned by providing a thrust ball bearing. For the case where the second reversing arm 33 is not installed, please refer to the attached Figure 10 Among them, the steel ball 9 can be used as the steel ball retainer in the middle of the plane thrust bearing, and the operating principle is the same as that of the plane thrust bearing, and the two magnets are used as the seat rings on both sides of the thrust ball bearing.

[0064] Specifically, a second center hole 331 and a third step hole 332 are coaxial and interconnected in the middle of the second reversing arm 33. The aperture of the third step hole 332 is larger than that of the second center hole 331. The second center hole 331 and the third step hole 332 can allow the second section 3611 of the transmission shaft 361 to pass through. A second bearing 38 is installed between the second reversing arm 33 and the second section 3611. The second bearing 38 is located in the third step hole 332; the third step hole 332 is located on the end of the second reversing arm 33 away from the driving gear 31.

[0065] Specifically, a first center hole is provided in the middle of the first commutating arm 32, through which the first section 3612 passes. A first stepped hole and a second stepped hole, each with a larger diameter than the first center hole, are provided at either end of the first center hole. The first stepped hole and the second stepped hole are coaxial with and interconnected with the first center hole. A first bearing 37 is installed between the first commutating arm 32 and the first section 3612. The first bearing 37 is installed in the first stepped hole, and the first magnet 3101 is installed in the second stepped hole. In other words, circular stepped holes are provided at both axial ends of the first commutating arm 32. The two circular stepped holes are concentric and extend through the first commutating arm 32, and the first magnet 3101 and the first bearing 37 are installed in the stepped holes on either side, respectively.

[0066] Specifically, a first through-hole 321 and a second through-hole 322 are respectively provided at both ends of the first reversing arm 32 and the second reversing arm 33. A central axis is protruded from the center of each end of the first driven gear 34 and the second driven gear 35. The central axis at both ends of the first driven gear 34 is rotatably inserted into the two first through-holes 321, and the central axis at both ends of the second driven gear 35 is rotatably inserted into the two second through-holes 322. The first through-hole 321 and the second through-hole 322 are both circular holes. That is, two sets of circular holes are further provided at the ends of the first reversing arm 32 and the second reversing arm 33 in the arm span direction. The two sets of circular holes are respectively used to concentrically connect one end of the central axis of the first driven gear 34 and the central axis of the second driven gear 35.

[0067] Specifically, a retaining spring 39 is detachably mounted on the transmission shaft 361 , and a slot for mounting the retaining spring 39 is provided on the side of the transmission shaft 361 . The second reversing arm 33 , the driving gear 31 , and the first reversing arm 32 are all located between the slot and the motor 36 . Since the two ends of the first reversing arm 32 and the second reversing arm 33 are connected by the first driven gear 34 and the second driven gear 35, the distance between the first reversing arm 32 and the second reversing arm 33 can be determined by the first driven gear 34 and the second driven gear 35. The first magnet 3101 and the second magnet 3102 are respectively located at the two ends of the first reversing arm 32 and the driving gear 31 close to each other. By setting a step surface and a retaining spring 39 groove on the transmission shaft 361 of the motor 36, the driving gear 31 and the second reversing arm 33 can be axially positioned, so that by limiting the position of the driving gear 31 on the transmission shaft 361, the distance between the two magnets can be kept constant, that is, the step surface 3613 and the retaining spring 39 groove cooperate with the retaining spring 39 to axially position the magnet in the switching assembly 3.

[0068] Specifically, the feed assembly 1 further includes a passive wheel 13, which is fixed to the feed channel 12. The passive wheel 13 and the feed gear 15 jointly compress the printing wire and convey the printing wire along the feed channel 12. A transmission gear 11 is provided at the shaft end of the feed gear 15. The transmission gear 11 is coaxially arranged with the feed gear 15 and can rotate synchronously. The transmission gear 11 is used to engage with the first driven gear 34 for transmission, wherein the feed gear 15 is used to compress the material and advance the material. The transmission gear 11 is used to transmit the power of the motor. When the first driven gear 34 rotates to the first working station 41, it engages with the transmission gear 11, which can drive the feed gear 15 to rotate and realize feeding. The feed assembly 1 also includes a compression spring 14, which is used to press the feed gear 15 and the passive wheel 13. The compression spring 14 is concentrically connected and abuts against the feed assembly. The raised ring can prevent the spring from running. The other end of the compression spring 14 abuts against the bracket. The two ends of the feed channel 12 are respectively provided with a feed port 121 and a discharge port 122. The discharge port 122 is provided with a tubular claw for connecting a Teflon tube. The Teflon tube is used to transport the printing wire to the next level device. The feed assembly 1 also includes a common consumable position detection mechanism for detecting the position of the printing wire. According to actual usage, the return assembly can be set to include at least two meshing return gears 2, wherein the number of the return gears 2 in the return assembly is an even number. One of the return gears 2 on one side of the return assembly is meshed with the wire support roller 5. The feeding and unloading device of the 3D printer of this solution further includes a bracket 4, which is used to fix the feeding component 1, the unloading component, and the switching component 3. The specific structure of the bracket 4 can be set according to actual usage.

[0069] A material feeding and withdrawing method for a 3D printer, using the material feeding and withdrawing device of the 3D printer as described above, wherein the support 4 is provided with a first working station 41, a second working station 42, and a non-working station, and the material feeding and withdrawing method comprises the following steps:

[0070] When the motor 36 drives the transmission shaft 361 to rotate counterclockwise, the first reversing arm 32 follows the transmission shaft 361 to rotate to the first working station 41. At this time, the first driven gear 34 is engaged with the transmission gear 11 at the shaft end of the feed gear 15 for transmission. The driving force of the motor shaft of the motor 36 is transmitted to the feed gear 15 through the engagement transmission of the first driven gear 34 and the transmission gear 11 to realize feeding. At this time, the second driven gear 35 is away from the unloading gear 2, wherein the magnetic attraction between the first magnet 3101 and the second magnet 3102 can drive the first reversing arm 32 to rotate synchronously with the drive gear 31, and this magnetic attraction is less than the driving force transmitted to the feed gear 15 by the motor 36. When the motor 36 drives the transmission shaft 361 to rotate clockwise, the first reversing arm 32 follows the transmission shaft 361 to rotate to the second working station 42. At this time, the second driven gear 35 is engaged with the material removal gear 2 for transmission. The driving force of the motor 36 will be transmitted to the support roller 5 through the material removal gear 2 in the material removal assembly, and is used to rotate the material tray 6 for material removal. At this time, the first driven gear 34 is away from the feed gear 15. When the first reversing arm 32 can be rotated to the non-working position, the first driven gear 34 is not engaged with the feed gear 15 for transmission, and the second driven gear 35 is not engaged with the material removal gear 2 for transmission, that is, there is a gap between the first driven gear 34 and the feed gear 15, and there is a gap between the second driven gear 35 and the material removal gear 2. Refer to the attached Figure 3 As shown, when it is necessary to adjust to the non-working position, the non-working position can be reached by rotating the motor by an angle. This angle can be set according to the relative positions of the first reversing arm 32 and the first working station 41 and the second working station 42, so that the first driven gear 34 and the second driven gear 35 are not close to the corresponding first working station 41 and the second working station 42. After adjusting to the non-working position, the motor 36 will no longer work, and the first reversing arm 32 will remain in the same state with the motor shaft due to the magnetic attraction force, so the driving gear and the two driven gears will no longer rotate.

[0071] Other details of the material feeding and withdrawing device and material feeding and withdrawing method of the 3D printer described in the present invention can be found in the prior art and will not be repeated here.

[0072] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Therefore, any modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A material feeding and withdrawing device for a 3D printer, characterized in that: The transmission gear of the present invention is a gear which is connected to the transmission shaft by a first gear and a second gear which is connected to the transmission shaft by a second gear. The second magnet is arranged on the driving gear, and the first magnet is arranged on the first reversing arm; the transmission shaft includes a first section and a second section that are coaxial and fixedly connected to each other, the end of the first section away from the second section is rotatably connected to the motor, the diameter of the first section is larger than the diameter of the second section, and the first section forms a step surface on the end face connected to the second section, and the driving gear is detachably mounted on the second section and can abut against the step surface; the first reversing arm is rotatably mounted on the first section; the first magnet is installed on the side of the first reversing arm close to the driving gear, and the second magnet is installed on the side of the driving gear close to the first reversing arm; the second magnet is provided with a mounting groove, the notch of the mounting groove is facing the direction of the first magnet, and a number of steel balls are provided in the mounting groove, each of the steel balls partially protrudes from the mounting groove, and the centers of the several steel balls are located in a plane perpendicular to the axis of the transmission shaft.

2. The material feeding and withdrawing device of the 3D printer according to claim 1, characterized in that: The switching assembly also includes a second reversing arm, which is rotatably mounted on the second section. The driving gear is located between the first reversing arm and the second reversing arm. Both ends of the first driven gear and the second driven gear are rotationally connected to the first reversing arm and the second reversing arm respectively.

3. The material feeding and withdrawing device of the 3D printer according to claim 2, characterized in that: A second center hole and a third step hole are coaxial and interconnected in the middle of the second reversing arm. The second center hole and the third step hole can both allow the second section to pass through. A second bearing is installed between the second reversing arm and the second section, and the second bearing is located in the third step hole; the third step hole is located on the end of the second reversing arm away from the drive gear.

4. The material feeding and withdrawing device of the 3D printer according to claim 3, characterized in that: A first central hole is provided in the middle of the first reversing arm for the first section to pass through, and a first stepped hole and a second stepped hole are provided at both ends of the first central hole, each having a diameter larger than that of the first central hole. The first stepped hole and the second stepped hole are coaxial with the first central hole and are connected to each other. A first bearing is installed between the first reversing arm and the first section. The first bearing is installed in the first step hole. The first magnet is installed in the second step hole.

5. The material feeding and withdrawing device of the 3D printer according to claim 3, characterized in that: A first through hole and a second through hole are respectively provided at both ends of the first reversing arm and the second reversing arm. A central axis is protruded from the center of both ends of the first driven gear and the second driven gear. The central axis at both ends of the first driven gear can be rotatably inserted into the two first through holes, and the central axis at both ends of the second driven gear can be rotatably inserted into the two second through holes.

6. The material feeding and withdrawing device of the 3D printer according to claim 5, characterized in that: A retaining ring is detachably mounted on the transmission shaft, a slot for mounting the retaining ring is provided on the side of the first section, and the second reversing arm, the driving gear, and the first reversing arm are all located between the slot and the motor.

7. The material feeding and withdrawing device of a 3D printer according to claim 1, characterized in that: The feeding assembly further includes a passive wheel, which is fixed on the feeding channel, and the passive wheel and the feeding gear jointly compress the printing wire and convey the printing wire along the feeding channel; A transmission gear is provided at the shaft end of the feed gear, the transmission gear is coaxially arranged with the feed gear and can rotate synchronously, and the transmission gear is used to mesh with the first driven gear for transmission; The feeding assembly further includes a compression spring, and the compression spring is used to compress the feeding gear and the passive wheel; The two ends of the feed channel are respectively provided with a feed port and a discharge port, and the discharge port is provided with a tubular claw for connecting a Teflon tube, and the Teflon tube is used to transport the printing wire to the next level device; The feeding assembly also includes a consumables position detection mechanism for detecting the position of the printing wire.

8. A material feeding and withdrawing method for a 3D printer, using the material feeding and withdrawing device for a 3D printer according to any one of claims 1 to 7, characterized in that: The bracket is provided with a first working station, a second working station and a non-working station, and the feeding and withdrawing device further comprises a withdrawing assembly, and the withdrawing assembly comprises a withdrawing gear; The material feeding and withdrawing method comprises the following steps: When the motor drives the transmission shaft to rotate counterclockwise, the first reversing arm follows the transmission shaft to rotate to the first working position, at which time the first driven gear is engaged with the feed gear for transmission, and the driving force of the motor is transmitted to the feed gear to realize feeding; when the motor drives the transmission shaft to rotate clockwise, the first reversing arm follows the transmission shaft to rotate to the second working position, at which time the second driven gear is engaged with the unloading gear for transmission, and the unloading gear rotates the material tray through the support roller to unload the material; when the first reversing arm rotates to the non-working position, the first driven gear is not engaged with the feed gear for transmission, and the second driven gear is not engaged with the unloading gear for transmission; wherein, the support roller is engaged with the material tray.

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