Selecting a feed mechanism and a three-dimensional printer

Abstract

The present application relates to a selection feeding mechanism, which comprises a mounting carrier, a wire limiting structure and a selection feeding mechanism; the wire limiting structure comprises an inlet end, an outlet end and an exposed part between the inlet end and the outlet end; the selection feeding mechanism comprises a feeding shaft, a selection shaft and a driving device; the feeding shaft is provided with a feeding wheel; the selection shaft is provided with a selection convex part; the wire limiting structure, the feeding wheel and the selection convex part are at least two groups, and the selection convex parts of each group are arranged in dislocation around the selection shaft; the selection feeding mechanism further comprises a switching structure, and the driving device is drivingly connected with at least one of the feeding shaft and the selection shaft through the switching structure. The present application can drive the three-dimensional printing wire to move by only one driving device, and can also realize the switching between the three-dimensional printing wires of each group of wire limiting structures, so as to simplify the structure, reduce the manufacturing cost, assembly difficulty and realize miniaturization.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and particularly to a feeding mechanism and a 3D printer. Background Technology

[0002] As 3D printing technology rapidly develops towards multi-material, high-precision, and automated directions, multi-bin switching printing has become a core function to meet the needs of complex model making. As a key component connecting the bin storage and the print head, the performance of the bin feeding mechanism directly determines the printing efficiency, material switching stability, and printing quality. Among these, the convenience and simplification of multi-slot bin switching have become the focus of industry research and development.

[0003] Currently, multi-slot material feeding mechanisms mostly rely on multi-motor drives to achieve slot switching. This not only increases the overall size and manufacturing cost of the mechanism, but also increases the complexity of equipment assembly and maintenance. It is not conducive to the miniaturization and lightweight design of printers, and it is also difficult to meet the usage needs of home and small industrial 3D printers. Summary of the Invention

[0004] One object of the present invention is to solve or alleviate the above-mentioned technical problems.

[0005] The present invention employs a feeding mechanism, which includes a mounting carrier, a filament limiting structure, and a feeding mechanism. The filament limiting structure includes an inlet end, an outlet end, and an exposed portion located between the inlet end and the outlet end. The feeding mechanism includes a feeding shaft, a selecting shaft, and a driving device. The feeding shaft is provided with a feeding wheel. The selecting shaft is provided with a selecting protrusion. The filament limiting structure, the feeding wheel, and the selecting protrusion are in at least two sets, and the selecting protrusions in each set are staggered around the selecting shaft. The feeding mechanism also includes a switching structure, and the driving device is connected to at least one of the feeding shaft and the selecting shaft through the switching structure. When the feeding shaft rotates in the forward direction to drive the 3D printing filament to move from the inlet end to the outlet end, the selecting shaft stops rotating and maintains its rotational position. When the feeding shaft rotates in the reverse direction or stops rotating, the selecting shaft rotates, causing the selecting protrusions in each set to rotate around the selecting shaft.

[0006] The advantages of this invention are that a single driving device can drive the movement of the 3D printing filament and can also switch between the 3D printing filaments of each group of filament limiting structures, thereby simplifying the structure, reducing manufacturing costs, assembly difficulty, and miniaturization.

[0007] A further technical solution includes a feeding shaft gear and a drive wheel connected to the drive device. The switching structure is a unidirectional rotation structure. The feeding shaft is fixedly connected to the drive wheel and a feeding shaft gear is fixedly installed. The feeding shaft gear is connected to the feeding shaft through the unidirectional rotation structure and meshes with the feeding shaft gear.

[0008] This technical solution can further simplify the structure and reduce costs.

[0009] In a further technical solution, the feeding mechanism also includes an extrusion assembly, which includes an extrusion wheel and an extrusion carrier fixedly connected to the feeding shaft; the extrusion wheel and the extrusion carrier are directly or indirectly hinged, and the feeding protrusion is located on the extrusion wheel.

[0010] This technical solution ensures that the 3D printing filament is smoothly driven by the feeding wheel when the drive wheel rotates in the forward direction; and ensures that the selection shaft rotates smoothly until the selection protrusion is directly opposite the feeding wheel when the drive wheel rotates in the reverse direction.

[0011] In a further technical solution, the feeding mechanism also includes an extrusion elastic element and an extrusion movable element movably connected to the extrusion carrier. The extrusion wheel is hinged to the extrusion movable element. The extrusion elastic element is connected to the extrusion carrier and the extrusion movable element respectively, so that the extrusion movable element tends to move closer to the feeding shaft. The extrusion carrier is provided with a limiting shaft for limiting the position of the extrusion movable element closest to the feeding shaft.

[0012] This technical solution ensures that even if the protrusion size of the material selection protrusion is inaccurate due to processing error factors, the 3D printing filament can be smoothly driven by the feeding wheel when the drive wheel rotates in the forward direction. It also ensures that when the drive wheel rotates in the reverse direction, the material selection shaft can be smoothly rotated until the material selection protrusion is directly opposite the feeding wheel, thereby reducing the precision requirements of the extrusion assembly.

[0013] A further technical solution also includes an angle recognition structure for reading the rotational position of the material selection shaft; the driving wheel is a worm gear, and a worm gear meshing with the worm gear is fixedly installed at the rotational output end of the drive device.

[0014] This technical solution ensures that the rotation position of the material selection shaft read by the angle recognition structure is accurate.

[0015] A further technical solution includes an angle recognition structure comprising a sensor and a code disk fixedly connected to the material selection shaft. The code disk has a code disk notch. The number of sensors, code disks, and code disk notches is equal and is A. The number of wire limiting structures is B. The sensors and code disks correspond one-to-one, and the sensor can read the code disk notch information on the code disk of the corresponding sensor.

[0016] This technical solution can reduce costs and improve reliability.

[0017] A further technical solution includes a switching structure comprising planetary gear one, planetary gear two, a sun gear, and a planetary gear carrier. The planetary gear carrier is equipped with planetary gear arm one and planetary gear arm two. Planetary gear one is hinged to planetary gear arm one, and planetary gear two is hinged to planetary gear arm two. The sun gear is fixed relative to the driving wheel and hinged to the mounting carrier. The planetary gear carrier can rotate relative to the sun gear. A feeding shaft is fixedly equipped with a feeding shaft gear, and a selection shaft is fixedly equipped with a selection shaft gear. Planetary gear one and planetary gear two are respectively meshed with the sun gear. When planetary gear one is meshed with the feeding shaft gear, planetary gear two is disengaged from the selection shaft gear. When planetary gear one is disengaged from the feeding shaft gear, planetary gear two is meshed with the selection shaft gear.

[0018] A further technical solution is provided, wherein the planetary gear carrier limiting part includes a feeding limiting part and a material selection limiting part; when planetary gear one meshes with the feeding shaft gear, and planetary gear two disengages from the material selection shaft gear, planetary gear arm one abuts against the feeding limiting part; when planetary gear one disengages from the feeding shaft gear, and planetary gear two meshes with the material selection shaft gear, planetary gear arm two abuts against the material selection limiting part.

[0019] This technical solution can ensure the accurate rotational position of the planetary gear carrier and improve reliability.

[0020] A further technical solution is that the planetary gear carrier can rotate until planetary gear two disengages from the material selection shaft gear and planetary gear one disengages from the feeding shaft gear.

[0021] This technical solution allows for easy extraction of the 3D printing filaments within each filament limiting structure, facilitating maintenance and repair.

[0022] The present invention employs a 3D printer, including the aforementioned feeding mechanism. Attached Figure Description

[0023] Figure 1 This is a three-dimensional schematic diagram of the feeding mechanism in the first embodiment. Figure 1 .

[0024] Figure 2 This is a three-dimensional schematic diagram of the feeding mechanism in the first embodiment. Figure 2 .

[0025] Figure 3 This is a partial perspective view of the feeding mechanism in the first embodiment.

[0026] Figure 4 This is a front view schematic diagram of the feeding mechanism in the first embodiment.

[0027] Figure 5 This is a schematic diagram of section SEC1.

[0028] Figure 6 This is a schematic diagram of section SEC2; line LINE1 represents a circle with the same center line as the material selection axis 22.

[0029] Figure 7 This is a schematic diagram of section 3 SEC3.

[0030] Figure 8 This is a schematic diagram of section 4, SEC4.

[0031] Figure 9 This is a schematic diagram of section 5, SEC5.

[0032] Figure 10 This is a partial perspective view of the feeding mechanism in the second embodiment.

[0033] Figure 11 This is a front view schematic diagram of the feeding mechanism in the second embodiment.

[0034] Figure 12 This is a schematic diagram of section 6 SEC6.

[0035] The accompanying drawings, which best illustrate the technical features of this invention, are Figure 6 .

[0036] Section 1 (SEC1); Section 2 (SEC2); Section 3 (SEC3); Section 4 (SEC4); Section 5 (SEC5); Section 6 (SEC6); Line 1 (LINE1); Mounting carrier 1; Wire limiting structure 11; Feed end 111; Discharge end 112; Exposed part 113; Planetary gear holder limiting part 13; Feeding limiting part 131; Selecting limiting part 132; Selecting and feeding mechanism 2; Feeding shaft 21; Feeding wheel 218; Feeding shaft gear 219; Selecting shaft 22; Selecting protrusion 221; Selecting shaft gear 229; Switching structure 23; Planetary gear 1 231; Line Star gear 232; Sun gear 233; Planetary gear carrier 234; Planetary gear arm 1 235; Planetary gear arm 236; Extrusion assembly 24; Extrusion carrier 241; Extrusion movable part 242; Extrusion elastic part 243; Extrusion wheel 244; Limiting shaft 245; Drive device 29; Drive wheel 298; Worm gear 299; Angle recognition structure 3; Sensor 31; Sensor 1 311; Sensor 2 312; Sensor 3 313; Circuit board 319; Encoder 32; Encoder 1 321; Encoder 2 322; Encoder 3 323; Encoder notch 329. Detailed Implementation

[0037] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0038] As a specific embodiment, the feeding mechanism of the first embodiment includes an installation carrier 1, a wire limiting structure 11, and a feeding mechanism 2.

[0039] The filament limiting structure 11 includes an inlet end 111, an outlet end 112, and an exposed portion 113 located between the inlet end 111 and the outlet end 112. For example, the filament limiting structure 11 is a cylindrical shape integrally formed on the mounting carrier 1, with a notch in its middle, allowing the inner cavity of the cylindrical shape to communicate with the outside of the cylindrical shape and thus be exposed. After the 3D printing filament is inserted from the inlet end 111, it can extend from the outlet end 112, and the portion of the 3D printing filament located between the inlet end 111 and the outlet end 112 is also exposed from the exposed portion 113, thereby being able to contact the feed roller 218 and the material selection protrusion 221, which will be described later. Of course, the filament limiting structure 11 can also be other structures used to limit the 3D printing filament to contact with the feed roller 218 and the material selection protrusion 221.

[0040] The feeding mechanism 2 includes a feeding shaft 21, a selection shaft 22, and a drive device 29.

[0041] The feed shaft 21 is equipped with a feed wheel 218. Typically, the feed wheel 218 has several grooves to increase the friction between it and the 3D printing filament.

[0042] The material selection shaft 22 is provided with a material selection protrusion 221.

[0043] The filament limiting structure 11, the feeding wheel 218, and the material selection protrusion 221 are in at least two sets, and the material selection protrusion 221 of each set is staggered around the material selection axis 22. It is easy to understand that for the same set of filament limiting structure 11, feeding wheel 218, and material selection protrusion 221, the feeding wheel 218 of that set cooperates with the material selection protrusion 221 of that set to drive the 3D printing filament in the filament limiting structure 11 of that set to extend out from the inlet end 111 and the outlet end 112. It is easy to understand that the material selection protrusions 221 of each group are all misaligned around the material selection axis 22. Therefore, when the material selection protrusions 221 of each group of filament limiting structures 11, feeding wheels 218, and material selection protrusions 221 are aligned and can clamp the 3D printing filament, the material selection protrusions 221 of other groups of filament limiting structures 11, feeding wheels 218, and material selection protrusions 221 are all misaligned and cannot clamp the 3D printing filament.

[0044] For example, the wire limiting structure 11, the feeding wheel 218, and the material selection protrusions 221 are in six groups. The material selection protrusions 221 in each group are evenly distributed around the material selection axis 22. In other words, the central angle positions of the material selection protrusions 221 in two groups differ by sixty degrees.

[0045] The feeding mechanism 2 also includes a switching structure 23. The drive device 29 is connected to at least one of the feeding shaft 21 and the selection shaft 22 through the switching structure 23. When the feeding shaft 21 rotates in the forward direction to drive the 3D printing filament to move from the inlet end 111 to the outlet end 112, the selection shaft 22 stops rotating and maintains its rotational position. When the feeding shaft 21 rotates in the reverse direction or stops rotating, the selection shaft 22 rotates and drives the selection protrusions 221 of each group to rotate around the selection shaft 22.

[0046] The working principle is as follows: Figure 6 As shown, in this group of wire limiting structure 11, feeding wheel 218, and material selection protrusion 221, the feeding wheel 218 and the material selection protrusion 221 are directly opposite each other. At this time, the drive device 29 drives the feeding shaft 21 to rotate in the forward direction (in Figure 6 When the feed shaft 21 rotates counterclockwise (the forward rotation is the same as the counterclockwise rotation), the feed roller 218 of this group and the selection protrusion 221 of the same group clamp the 3D printing filament. Therefore, the feed roller 218 of this group can provide a large driving force such as friction to the 3D printing filament, thereby causing the 3D printing filament of this group to move from the inlet end 111 of this group to the outlet end 112 of this group. At the same time, for the filament limiting structure 11, feed roller 218, and selection protrusion 221 of other groups, although the feed shaft 21 is still rotating counterclockwise, as mentioned above, the feed roller 218 of other groups is misaligned with the selection protrusion 221. At this time, the pressure between the 3D printing filament and the feed roller 218 is small or non-existent, and the feed roller 218 cannot provide a large driving force such as friction to the 3D printing filament, thereby preventing the 3D printing filament of other groups from moving from the inlet end 111 of other groups to the outlet end 112 of other groups.

[0047] Reference Figure 6 When it is necessary to switch materials, the drive device 29 directly or indirectly drives the feeding shaft 21 to rotate in the opposite direction or cannot drive the feeding shaft 21 to rotate (i.e., the selection shaft 22 stops rotating). The selection shaft 22 rotates and drives the selection protrusions 221 of each group to rotate around the selection shaft 22 until the feeding wheel 218 of one of the other groups is aligned with the selection protrusion 221. Then the drive device 29 drives the feeding shaft 21 of one of the other groups to rotate in the forward direction. As mentioned above, the 3D printing filament of the filament limiting structure 11 of one of the other groups is driven by the feeding wheel 218 of one of the other groups and moves from the inlet end 111 of one of the other groups to the outlet end 112.

[0048] In summary, the feeding mechanism of the first embodiment can drive the movement of the 3D printing filament with only one driving device 29, and can also realize the switching between the 3D printing filaments of each group of filament limiting structures 11, thereby simplifying the structure, reducing manufacturing costs, assembly difficulty and miniaturization.

[0049] As one specific implementation, the feeding mechanism 2 also includes a feeding shaft gear 219 and a drive wheel 298 driven by the drive device 29. The switching structure 23 is a unidirectional rotation structure. The feeding shaft 22 is fixedly connected to the drive wheel 298 and a feeding shaft gear 229 is fixedly installed thereon. The feeding shaft gear 219 is connected to the feeding shaft 21 through the unidirectional rotation structure, and the feeding shaft gear 219 meshes with the feeding shaft gear 229. It should be noted that the unidirectional rotation structure should be interpreted broadly. In addition to the unidirectional bearing in the prior art, other structures that only allow unidirectional rotation, such as ratchet structures, should also be understood as the unidirectional rotation structure. When the drive device 29 drives the drive wheel 298 to rotate in the forward direction, the drive wheel 298 drives the feeding shaft gear 229 to rotate in the forward direction through the feeding shaft 22 (in... Figure 5 In the middle, the forward rotation of the material selection shaft 22 is clockwise. At this time, the material selection shaft gear 229 drives the feeding shaft 21 and the feeding wheel 218 to rotate clockwise through the feeding shaft gear 219. Figure 5 In the process, the forward rotation of the feeding shaft 21 is counterclockwise; when the drive device 29 drives the drive wheel 298 to rotate in the opposite direction, the drive wheel 298 drives the selection shaft gear 229 to rotate in the opposite direction via the selection shaft 22 (in... Figure 5 In the middle, the forward rotation of the material selection shaft 22 is counterclockwise), at this time, although the feeding shaft gear 219 rotates in the opposite direction (in Figure 5 In this embodiment, the reverse rotation of the feed shaft gear 219 is clockwise, but the feed shaft gear 219 cannot drive the feed shaft 21 to rotate in the reverse direction through the unidirectional rotation structure. It is easy to understand that when the drive device 29 drives the drive wheel 298 to rotate in the forward direction, the drive device 29 can drive the movement of the 3D printing filament. When the drive device 29 drives the drive wheel 298 to rotate in the reverse direction, the drive device 29 can switch between the 3D printing filaments of each group of filament limiting structures 11. In this embodiment, only a one-way bearing or similar device is needed to drive the movement of the 3D printing filament with only one drive device 29, and it can also switch between the 3D printing filaments of each group of filament limiting structures 11, further simplifying the structure and reducing costs.

[0050] As one specific implementation, the feeding mechanism 2 further includes an extrusion assembly 24, which includes an extrusion wheel 244 and an extrusion carrier 241 fixedly connected to the feeding shaft 22. The extrusion wheel 244 and the extrusion carrier 241 are directly or indirectly hinged, and the feeding protrusion 221 is located on the extrusion wheel 244. For example, the extrusion wheel 244 is directly hinged to the extrusion carrier 241 via a pin or the like. In this implementation, when the driving device 29 drives the drive wheel 298 to rotate forward and drives the 3D printing filament to move, the friction between the feeding protrusion 221 and the 3D printing filament is rolling friction, which can reduce the frictional force between the feeding protrusion 221 and the 3D printing filament, thereby ensuring that the 3D printing filament is smoothly driven by the feeding wheel 218 when the drive wheel 298 rotates forward. When the drive device 29 drives the drive wheel 298 to rotate in the opposite direction and realizes the switching between the three-dimensional printing filaments of each group of filament limiting structures 11, the friction between the material selection protrusion 221 and the three-dimensional printing filament is also rolling friction. Even if the output torque of the drive device 29 is small, it can ensure that when the drive wheel 298 rotates in the opposite direction, the material selection shaft 22 rotates smoothly until the material selection protrusion 221 is aligned with the feeding wheel 218.

[0051] As one specific implementation, the feeding mechanism 2 further includes a pressing elastic element 243 and a pressing movable element 242 movably connected to the pressing carrier 241. For example, the pressing movable element 242 is linearly slidably connected to the pressing carrier 241; the pressing wheel 244 is hinged to the pressing movable element 242, thereby indirectly hinged to the pressing carrier 241; the pressing elastic element 243 is connected to the pressing carrier 241 and the pressing movable element 242 respectively, so that the pressing movable element 242 tends to move closer to the feeding shaft 21; the pressing carrier 241 is provided with a limiting shaft 245 for limiting the position of the pressing movable element 242 closest to the feeding shaft 21. For example, the extrusion elastic element 243 is a spring, and its two ends abut against the extrusion carrier 241 and the extrusion movable element 242, respectively. The limiting shaft 245 abuts against the extrusion movable element 242, limiting the position of the extrusion movable element 242 closest to the feeding shaft 21. Therefore, under the limitation of the limiting shaft 245, the extrusion movable element 242 can only move away from the feeding shaft 21 and cannot continue to move closer to the feeding shaft 21. In this embodiment, even the protrusion size of the material selection protrusion 221 (e.g. Figure 6 As shown, the protruding dimension refers to the radial dimension of the selection protrusion 221 based on line LINE1, which is inaccurate due to processing error factors. The elastic force provided by the extrusion elastic element 243 can also ensure that the 3D printing filament is smoothly driven by the feed wheel 218 when the drive wheel 298 rotates in the forward direction, and can also ensure that the selection shaft 22 rotates smoothly until the selection protrusion 221 is directly opposite the feed wheel 218 when the drive wheel 298 rotates in the reverse direction, thereby reducing the accuracy requirements of the extrusion assembly 24.

[0052] As one of the specific embodiments, the material selecting and feeding mechanism of the first embodiment further comprises an angle recognition structure 3 for reading the rotation position of the material selecting shaft 22; the driving device 29 is a servo motor, the driving wheel 298 is a worm gear, and a worm 299 meshed with the worm gear is fixedly arranged at the rotation output end of the driving device 29, and the driving device 29 is started to drive the driving wheel 298 to rotate. In this embodiment, only the driving device 29 can drive the material selecting shaft 22 to rotate, and the material selecting shaft 22 cannot drive the worm 299 of the driving device 29 to rotate. Therefore, even when the three-dimensional printing wire is pulled out from the feeding end 111, the friction force of the three-dimensional printing wire on the material selecting convex portion 221 cannot drive the material selecting shaft 22 to rotate, and the rotation position of the material selecting shaft 22 read by the angle recognition structure 3 will not change due to the passive rotation of the material selecting shaft 22, thereby ensuring that the rotation position of the material selecting shaft 22 read by the angle recognition structure 3 is accurate.

[0053] As one of the specific embodiments, the angle recognition structure 3 comprises a sensor 31 and a code disc 32 fixedly connected with the material selecting shaft 22, a code disc notch 329 is arranged on the code disc 32, the number of the sensors 31, the number of the code discs 32 and the number of the code disc notches 329 are equal and A, the number of groups of the wire limiting structures 11 is B, and the sensors 31 are in one-to-one correspondence with the code discs 32 so as to be capable of reading information of the code disc notches 329 on the code disc 32 corresponding to the sensor 31; for example, the sensor 31 is a photoelectric sensor, when the code disc notch 329 faces the sensor 31, the sensor 31 reads an on information (for example, corresponding to binary 1), and when the code disc notch 329 is misaligned with the sensor 31, the sensor 31 reads an off information (for example, corresponding to binary 0). B is less than or equal to 2 to the power of A and greater than 2 to the power of (A minus 1), in other words, 2^(A-1)<B≤2^A. For example, the number of groups of the wire limiting structures 11 is six, the sensors 31 comprise a first sensor 311, a second sensor 312 and a third sensor 313, the first sensor 311, the second sensor 312 and the third sensor 313 are all arranged on a circuit board 319, and the code discs 32 comprise a first code disc 321, a second code disc 322 and a third code disc 323; the first code disc 321, the second code disc 322 and the third code disc 323 are all fixed on the material selecting shaft 22. The number of the sensors 31, the number of the code discs 32 and the number of the code disc notches 329 are equal and three, and two to the power of three is eight. Compared with the traditional method that adopts one code disc and a high-precision sensor, this embodiment has lower requirements for the precision of the sensor 31 and the precision of the code disc notch 329 on the code disc 32, and can reduce the cost and improve the reliability.

[0054] The material selecting and feeding mechanism of the second embodiment differs from that of the first embodiment in the switching structure 23 and the angle recognition structure 3.

[0055] As Figure 12As shown, the feeding mechanism of the second embodiment includes a switching structure 23 comprising a first planetary gear 231, a second planetary gear 232, a sun gear 233, and a planetary gear carrier 234. The planetary gear carrier 234 is provided with a first planetary gear arm 235 and a second planetary gear arm 236. The first planetary gear 231 is hinged to the first planetary gear arm 235, and the second planetary gear 232 is hinged to the second planetary gear arm 236. The sun gear 233 is fixed relative to the driving wheel 298 and hinged to the mounting carrier 1. The planetary gear carrier 234 can rotate relative to the sun gear 233. For example, a pin is fixedly connected to the sun gear 233 and the driving wheel 298 respectively. The planetary gear carrier 234 is hinged to the pin through a damping bearing or a regular bearing. A feeding shaft 21 is fixedly equipped with a feeding shaft gear 219, and a material selection shaft 22 is fixedly equipped with a material selection shaft gear 229; planetary gear one 231 and planetary gear two 232 are respectively meshed with the sun gear 233; when planetary gear one 231 is meshed with the feeding shaft gear 219, planetary gear two 232 is disengaged from the material selection shaft gear 229; when planetary gear one 231 is disengaged from the feeding shaft gear 219, planetary gear two 232 is meshed with the material selection shaft gear 229. When the drive unit 29 drives the drive wheel 298 to rotate in the forward direction, the drive unit 29 drives the drive wheel 298 and the sun gear 233 to rotate. The planetary gear carrier 234 is driven to rotate by the drive wheel 298 (relying on the damping force or friction of the pin shaft) until the first planetary gear 231 meshes with the feed shaft gear 219 and the second planetary gear 232 disengages from the selection shaft gear 229. At this time, the 3D printing filament can be driven to move. When the drive unit 29 drives the drive wheel 298 to rotate in the reverse direction, the planetary gear carrier 234 is driven to rotate by the drive wheel 298 until the first planetary gear 231 disengages from the feed shaft gear 219 and the second planetary gear 232 meshes with the selection shaft gear 229. At this time, the switching between the 3D printing filaments of each group of filament limiting structures 11 can be realized.

[0056] As one specific embodiment, the planetary gear carrier limiting part 13 includes a feeding limiting part 131 and a material selection limiting part 132. When planetary gear one 231 meshes with the feeding shaft gear 219, planetary gear two 232 disengages from the material selection shaft gear 229. When planetary gear one 231 disengages from the feeding shaft gear 219, planetary gear two 232 meshes with the material selection shaft gear 229. When planetary gear two 236 meshes with the material selection limiting part 132, planetary gear two 236 abuts against the material selection limiting part 132. This embodiment can ensure the accurate rotational position of the planetary gear carrier 234 and improve reliability.

[0057] As one specific implementation, the planetary gear carrier 234 can rotate until planetary gear two 232 disengages from the material selection shaft gear 229 and planetary gear one 231 disengages from the material feeding shaft gear 219. In this implementation, the material selection protrusions 221 of each group are misaligned with the material feeding wheel 218; in other words, no group of material selection protrusions 221 is directly opposite the material feeding wheel 218. That is, there is a state in which the 3D printing filaments in each group of filament limiting structures 11 can be easily pulled out, which facilitates maintenance, repair and other operations.

[0058] As one specific implementation, the angle recognition structure 3 includes a sensor 31 and a code disk 32 fixedly connected to the material selection shaft 22. The code disk 32 is provided with a code disk notch 329. This implementation can read the rotational position of the material selection shaft 22, thereby identifying the specific group number of the filament limiting structure 11 that is driving the movement of the 3D printing filament. It is easy to understand that when the 3D printing filaments of each group of filament limiting structures 11 have different specifications in terms of color, material, etc., the specifications of the 3D printing filaments are pre-matched with the specific group number of their corresponding filament limiting structures 11. The rotational position of the material selection shaft 22 can be read by the angle recognition structure 3, thereby enabling the identification of the specifications of the 3D printing filaments.

[0059] The terms used in this invention, such as "first," "second," etc., do not indicate any order, quantity, or importance, but are merely for distinction.

[0060] In this invention, terms such as "a," "an," etc., do not indicate a limitation on the quantity, but rather indicate the existence of at least one of the mentioned objects.

[0061] In this invention, terms indicating orientation or location such as top, bottom, side, longitudinal, transverse, middle, center, outside, inside, horizontal, vertical, left, right, above, below, etc., are used to indicate relative positions rather than absolute positions.

[0062] Terms used in this invention, such as "approximately," "generally," "approximately," and "similar," are limiting terms used to indicate features that are present but allow for certain deviations. The amount of deviation allowed may vary depending on the specific context; for example, for deviations in dimensions, the specific context may include, but is not limited to, relevant standards for dimensional tolerances.

Claims

1. A selective feeding mechanism, comprising an installation carrier (1), a wire limiting structure (11), and a selective feeding mechanism (2); the wire limiting structure (11) comprises an inlet end (111), an outlet end (112), and an exposed portion (113) located between the inlet end (111) and the outlet end (112); the selective feeding mechanism (2) comprises a feeding shaft (21), a selecting shaft (22), and a driving device (29); the feeding shaft (21) is provided with a feeding wheel (218); Its characteristics are, The material selection shaft (22) is provided with material selection protrusions (221); the wire limiting structure (11), the feeding wheel (218), and the material selection protrusions (221) are at least two sets, and the material selection protrusions (221) of each set are staggered around the material selection shaft (22); the material selection and feeding mechanism (2) also includes a switching structure (23), and the driving device (29) is connected to at least one of the feeding shaft (21) and the material selection shaft (22) through the switching structure (23), so that when the feeding shaft (21) rotates in the forward direction and can drive the three-dimensional printing wire to move from the infeed end (111) to the discharge end (112), the material selection shaft (22) stops rotating and maintains the rotation position of the material selection shaft (22); when the feeding shaft (21) rotates in the reverse direction or stops rotating, the material selection shaft (22) rotates and drives the material selection protrusions (221) of each set to rotate around the material selection shaft (22).

2. The feeding mechanism according to claim 1, characterized in that, The feeding mechanism (2) also includes a feeding shaft gear (219) and a drive wheel (298) that is driven and connected to the drive device (29). The switching structure (23) is a unidirectional rotation structure. The feeding shaft (22) is fixedly connected to the drive wheel (298) and the feeding shaft gear (229) is fixedly installed. The feeding shaft gear (219) is connected to the feeding shaft (21) through the unidirectional rotation structure, and the feeding shaft gear (219) meshes with the feeding shaft gear (229).

3. The feeding mechanism according to claim 1, characterized in that, The feeding mechanism (2) also includes an extrusion assembly (24), which includes an extrusion wheel (244) and an extrusion carrier (241) fixedly connected to the feeding shaft (22); the extrusion wheel (244) and the extrusion carrier (241) are directly or indirectly hinged, and the feeding protrusion (221) is located on the extrusion wheel (244).

4. The feeding mechanism according to claim 3, characterized in that, The feeding mechanism (2) also includes an extrusion elastic element (243) and an extrusion movable element (242) movably connected to the extrusion carrier (241). The extrusion wheel (244) is hinged to the extrusion movable element (242). The extrusion elastic element (243) is connected to the extrusion carrier (241) and the extrusion movable element (242) respectively, so that the extrusion movable element (242) tends to approach the feeding shaft (21). The extrusion carrier (241) is provided with a limiting shaft (245) for limiting the position of the extrusion movable element (242) closest to the feeding shaft (21).

5. The feeding mechanism according to claim 1, characterized in that, It also includes an angle recognition structure (3) for reading the rotation position of the material selection shaft (22); the drive wheel (298) is a worm wheel, and the rotation output end of the drive device (29) is fixedly provided with a worm (299) that meshes with the worm wheel.

6. The feeding mechanism according to claim 5, characterized in that, The angle recognition structure (3) includes a sensor (31) and a code disk (32) fixedly connected to the material selection shaft (22). The code disk (32) is provided with a code disk notch (329). The number of sensors (31), code disks (32), and code disk notches (329) is equal and is A. The number of groups of wire limiting structures (11) is B. The sensors (31) and code disks (32) correspond one-to-one and can read the code disk notch (329) information on the code disk (32) of the sensor (31).

7. The feeding mechanism according to claim 1, characterized in that, The switching structure (23) includes a first planetary gear (231), a second planetary gear (232), a sun gear (233), and a planetary gear carrier (234). The planetary gear carrier (234) is provided with a first planetary gear arm (235) and a second planetary gear arm (236). The first planetary gear (231) is hinged to the first planetary gear arm (235), and the second planetary gear (232) is hinged to the second planetary gear arm (236). The sun gear (233) is fixed relative to the driving wheel (298) and hinged to the mounting carrier (1). The planetary gear carrier (234) can be positioned relative to the sun gear. The gear (233) rotates, the feeding shaft (21) is fixedly equipped with the feeding shaft gear (219), and the material selection shaft (22) is fixedly equipped with the material selection shaft gear (229); planetary gear one (231) and planetary gear two (232) respectively mesh with the sun gear (233); when planetary gear one (231) meshes with the feeding shaft gear (219), planetary gear two (232) disengages from the material selection shaft gear (229); when planetary gear one (231) disengages from the feeding shaft gear (219), planetary gear two (232) meshes with the material selection shaft gear (229).

8. The feeding mechanism according to claim 7, characterized in that, The planetary gear carrier limiting part (13) includes a feeding limiting part (131) and a material selection limiting part (132); when planetary gear one (231) meshes with the feeding shaft gear (219) and planetary gear two (232) disengages from the material selection shaft gear (229), planetary gear arm one (235) abuts against the feeding limiting part (131); when planetary gear one (231) disengages from the feeding shaft gear (219) and planetary gear two (232) meshes with the material selection shaft gear (229), planetary gear arm two (236) abuts against the material selection limiting part (132).

9. The feeding mechanism according to claim 7, characterized in that, The planetary gear carrier (234) can rotate to the point where planetary gear two (232) disengages from the material selection shaft gear (229) and planetary gear one (231) disengages from the material feeding shaft gear (219).

10. A 3D printer, characterized by: Includes the feeding mechanism as described in any one of claims 1 to 9.

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