Material feeding mechanism, multi-material unit and 3D printing system

Abstract

A material feeding mechanism (100), comprising: a main body (110); a discharge coupling arrangement (120) connected to the main body (110); and a drive arrangement (130) configured to drive the discharge coupling arrangement (120) in such a way that it is switchable between (i) a first position relative to the main body (110) in which the discharge coupling arrangement (120) is drivenly coupled to a coil (200) in order to rotate the coil (200) under the drive of the drive arrangement (130) in order to wind a wire (300) around the coil (200); and (ii) a second position relative to the main body (110) in which the discharge coupling arrangement (120) is drivenly disconnected from the coil (200).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of 3D printing, in particular a material feeding mechanism, a multi-material unit and a 3D printing system. BACKGROUND

[0002] 3D printing systems are also known as three-dimensional printers, meaning they are devices that enable rapid prototyping. 3D printers can use binding materials such as special waxes, metal powders, or plastics to create three-dimensional objects by printing layers of these materials. Currently, a 3D printing system typically includes a 3D printer and a multi-material unit (MMU) that can automatically change the type or color of filament and feed it to the printer, depending on the printing requirements. SUMMARY

[0003] Embodiments of the present disclosure provide a material feeding mechanism, a multi-material unit and a 3D printing system.

[0004] According to a first aspect of the embodiments of the present disclosure, a material feeding mechanism is provided comprising: a main body; a discharge coupling arrangement connected to the main body; and a drive arrangement configured to drive the discharge coupling arrangement so that it is switchable between (i) a first position relative to the main body in which the discharge coupling arrangement is drivenly coupled to a coil in order to rotate the coil under the drive of the drive arrangement in order to wind a wire around the coil; and (ii) a second position relative to the main body in which the discharge coupling arrangement is drivenly disconnected from the coil.

[0005] According to a second aspect of the embodiments of the present disclosure, a multi-material unit is provided comprising: at least one coil around which at least one wire for a 3D printer is wound; and at least one material feed mechanism, wherein each material feed mechanism comprises the material feed mechanism described above, wherein the at least one material feed mechanism is provided for use with the respective at least one coil to feed the at least one wire to the 3D printer.

[0006] According to a third aspect of the embodiments of the present disclosure, a 3D printing system is provided comprising: a 3D printer; at least one coil around which at least one wire for the 3D printer is wound; and at least one material feeding mechanism, each material feeding mechanism comprising: a main body; a discharge coupling arrangement connected to the main body; and a drive arrangement configured to drive the discharge coupling arrangement such that it is switchable between (i) a first position relative to the main body in which the discharge coupling arrangement is drivenly coupled to a coil to rotate the coil under the drive of the drive arrangement in order to wind a wire around the coil;and (ii) a second position relative to the main body in which the discharge coupling arrangement is drive-disconnected from the coil, and wherein the at least one material feed mechanism is provided for use with the corresponding coil of the at least one coil to feed the at least one wire to the 3D printer.

[0007] According to the material feeding mechanism, the multi-material unit, and the 3D printing system provided by the embodiments of the present disclosure, the discharge coupling assembly and the drive assembly are arranged on the main body of the material feeding mechanism such that the drive assembly can drive the discharge coupling assembly to switch between the first position relative to the main body and the second position relative to the main body. In the first position, the discharge coupling assembly is drivenly coupled to the spool and can rotate the spool under the drive of the drive assembly to wind the wire around the spool, thereby preventing the wire from getting stuck or accumulating in the material feeding mechanism after discharge and thus improving the reliability and orderliness of the multi-material unit.In the second position, the discharge coupling assembly is drive-disconnected from the coil, and the 3D printing system can normally print a three-dimensional object. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic structure diagram of a material supply module in a multi-material unit according to some embodiments of the present disclosure; Fig. 2 is a right side view of the material feed module made of Fig. 1; Fig. Figure 3 is a left side view of the material feed module. Fig. 1; Fig. Figure 4 is a schematic structure diagram of the material feed module. Fig. 1 with a remote coil; Fig. 5 is an axonometric view of the material feeding mechanism from Fig. 4 in a first angle; Fig. Figure 6 is a schematic structure diagram of an unloading coupling arrangement in the material feed mechanism made of Fig. 5 in a first position according to some embodiments of the present disclosure; Fig. Figure 7 is a schematic structure diagram of the discharge coupling arrangement in the material feed mechanism of Fig. 5 in a second position according to some embodiments of the present disclosure; Fig. Figure 8 is a schematic structure diagram of the discharge coupling arrangement in the material feed mechanism of Fig. 5; Fig. Figure 9 is an exploded schematic representation of the unloading coupling arrangement. Fig. 8; Fig. Figure 10 is a schematic structure diagram of the material feeding mechanism. Fig. 5 with main body removed; Fig. Figure 11 is an axonometric view of the material feeding mechanism from Fig. 4 from a second perspective; Fig. Figure 12 is a schematic structure diagram of the material feeding mechanism. Fig. 11 with wire support frame removed; Fig. Figure 13 is a schematic structure diagram of a loading coupling arrangement in the material feed mechanism made of Fig. 12 in a third position according to some embodiments of the present disclosure; and Fig. Figure 14 is a schematic structure diagram of the loading coupling arrangement in the material feed mechanism of Fig. 12 in a fourth position according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0008] It is understood that, although terms such as "first," "second," and "third" may be used here to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are used merely to distinguish one element, component, region, layer, or part from another. Therefore, a first element, component, region, layer, or part described below may be referred to as a second element, component, region, layer, or part without deviating from the teaching of the present revelation.

[0009] To simplify the description, spatially relative terms such as "below," "under," "lower," "below," "above," and "above" can be used to describe the relationship between an element or feature and one or more other elements or features, as illustrated in the figures. It is understood that these spatially relative terms are intended to cover not only the orientations shown in the figures but also various orientations of a device in use or operation. For example, if the device in the figures is turned upside down, an element described as "below other elements or features," "among other elements or features," or "below other elements or features" is oriented so that it is "above other elements or features." Thus, the exemplary terms "below" and "under" can encompass both the "above" and "below" orientations.Terms such as "before" or "in front" and "after" or "then" can be used similarly to indicate, for example, the order in which light passes through elements. The device may also be oriented differently (rotated by 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly. Furthermore, it is understood that when a layer is described as "between two layers," this may be the only layer between the two layers, or there may be one or more intermediate layers.

[0010] The terms used herein serve only to describe specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include plural forms unless expressly stated in the context. It is further understood that the terms "comprise" and / or "include," when used in this description, specify the presence of the described features, sets, steps, processes, elements, and / or components, but do not exclude the presence or addition of one or more other features, sets, steps, processes, elements, components, and / or groups thereof. As used herein, the term "and / or" includes all combinations of one or more of the listed elements, and the expression "at least one of A and B" refers only to A, only to B, or to both A and B.

[0011] It is understood that when an element or layer is described as being "located on another element or layer", "connected to another element or layer", "coupled to another element or layer" or "arranged next to another element or layer", the element or layer may be located directly on top of another element or layer, directly connected to another element or layer, directly coupled to another element or layer, or arranged directly next to another element or layer, or there may be an intermediate element or layer.In contrast, there is no intermediate element or layer when an element is described as "directly on top of another element or layer," "directly connected to another element or layer," "directly coupled to another element or layer," or "directly adjacent to another element or layer." Under no circumstances, however, should "on" or "directly on" be interpreted as requiring a layer to completely cover the layer below it.

[0012] Embodiments of the present disclosure are described herein with reference to schematic representations (and intermediate structures) of idealized embodiments of the present disclosure. For this reason, deviations from the depicted form, for example due to manufacturing techniques and / or tolerances, are to be expected. Therefore, the embodiments of the present disclosure should not be interpreted as being limited to a specific shape of a region shown herein, but should include, for example, shape deviations caused by manufacturing. Thus, the region shown in a figure is schematic in nature, and its shape is intended neither to illustrate the actual shape of the region of a device nor to limit the scope of the present disclosure.

[0013] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as generally understood by those skilled in the art in the field to which this disclosure belongs. It is further understood that terms as defined in common dictionaries should be interpreted in such a way as to align their meaning with that in the relevant fields and / or in the context of this specification, and not in an ideal or overly formal sense, unless expressly defined herein.

[0014] In the related technology, a multi-material unit can comprise a material guide tube, a spool, a loading friction wheel, and a motor connected to the loading friction wheel. A wire is wound around the spool, and one end of the wire is in contact with the loading friction wheel. During loading, the motor drives the loading friction wheel to rotate forward, feeding the wire into the material guide tube. A 3D printer uses the wire in the material guide tube to perform the printing process. When the printing process is complete or the wire is replaced, the motor drives the loading friction wheel to rotate backward, retracting the wire from the material guide tube into the multi-material unit.

[0015] With the previous technique, however, the wire remains stuck or accumulates in the multi-material unit after being retracted, so that it can easily become entangled in other parts, which impairs the normal operation of the multi-material unit, and the messy wire leads to poor cleanliness of the multi-material unit.

[0016] Embodiments of the present disclosure provide a material feeding mechanism, a multi-material unit, and a 3D printing system. A drive assembly and a discharge coupling assembly are provided, wherein the drive assembly can be coupled to a coil via the discharge coupling assembly to drive the coil, cause it to rotate, and rewind a wire around the coil, thereby preventing the wire from becoming suspended or accumulating.

[0017] The present disclosure is described in detail below with reference to the embodiments. It is understood that, for a clearer illustration of the structures of the embodiments of the present disclosure, only a complete structure of some gears is shown in the drawings of the present disclosure, and that other gears are represented by a cylindrical structure, the structural details of which are not shown.

[0018] Fig. Figure 1 is a schematic structure diagram of a material feed module in a multi-material unit according to some embodiments of the present disclosure; Fig. Figure 2 is a right side view of the material feed module. Fig. 1; Fig. Figure 3 is a left side view of the material feed module. Fig. 1; and Fig. Figure 4 is a partial schematic structure diagram of the material feed module. Fig. 1 with a remote coil.

[0019] It is understood that the multi-material unit can include at least one material feed module and one material guide tube (not shown) shared by the at least one material feed module. If the 3D printer needs to use a filament of a specific color or material, the material feed module, along with the filament, feeds the filament into the material guide tube within the multi-material unit. A print motor in the 3D printer pulls the filament through the material guide tube and propels it to a heated end of the 3D printer to perform a printing operation. In an example of the Fig. The material feed module comprises a material feed mechanism 100, a spool 200, and a roll holder 400. A wire is wound around the spool 200, and the spool 200 is rotatably connected to the roll holder 400. The material feed mechanism 100 is connected to the roll holder 400.

[0020] Fig. Figure 5 is an axonometric view of the material feeding mechanism 100 in Fig. 4 in a first angle; Fig. Figure 6 is a schematic structure diagram of an unloading coupling arrangement in the material feeding mechanism of Fig. 5 in a first position; and Fig. Figure 7 is a schematic structure diagram of the discharge coupling arrangement in the material feed mechanism of Fig. 5 in a second position. To simplify the presentation, a Fig. 5 shown discharge friction wheel 150 in the Fig. 6 and Fig. 7 hidden. With reference to the Fig. 5 to 7 the material feeding mechanism 100 comprises a main body 110, a discharge coupling arrangement 120 and a drive arrangement 130.

[0021] The main body 110 can be a support component of the material feed mechanism 100, which can be connected to the coil 400. The main body 110 can be made of a common material such as a metallic material or a plastic material.

[0022] The discharge coupling assembly 120 and the drive assembly 130 are both coupled to the main body 110. The discharge coupling assembly 120 can be moved under the drive of the drive assembly 130 between a first position relative to the main body 110 (which is shown in Fig. 6 position shown) and a second position relative to the main body 110 (which is shown in Fig. 7 (position shown) can be switched.

[0023] When the discharge coupling assembly 120 is in the first position, it can be driven and coupled to the coil 200. The discharge coupling assembly 120 can transmit a drive force supplied by the drive assembly 130 to the coil 200, allowing the coil 200 to rotate under the drive of the drive assembly 130 to wind the wire around the coil 200.

[0024] When the discharge coupling arrangement 120 is in the second position, the discharge coupling arrangement 120 is drive-wise disconnected from the coil 200, i.e., the drive force of the drive arrangement 130 cannot be transmitted to the coil 200.

[0025] The drive assembly 130 can include a motor capable of outputting rotary or linear motion, a hydraulic cylinder, an air cylinder, etc. Various configurations of the discharge coupling assembly 120 are also possible. In some embodiments, the drive assembly 130 can include a rotary motor capable of outputting rotary motion and a linear motor capable of outputting linear motion; a rotating shaft of the coil 200 can be provided with a driven gear; and the discharge coupling assembly 120 can include a drive gear that can engage with the driven gear. In some embodiments, the drive assembly 130 can include a rotary motor but not a linear motor, as described in more detail below.

[0026] In one embodiment, where the drive arrangement 130 includes a linear motor, the linear motor can be attached to the main body 110, a motor housing of the rotary motor can be coupled to an output shaft of the linear motor, and an output shaft of the rotary motor can be coaxially connected to the drive gear. The linear motor can drive the rotary motor and the drive gear synchronously to move in a linear direction, thus switching the drive gear between the first and second positions. When the drive gear is in the first position, the rotary motor can drive the drive gear to rotate, and the coil 200 is driven to rotate by the driven gear meshing with the drive gear to wind the wire around the coil 200.When the drive wheel is in the second position, the drive wheel is separated from the driven gear, and no power can be transferred from the rotary motor to the driven gear.

[0027] It should be noted that when the 3D printer has completed the printing process or a wire change is required, the drive assembly 130 drives the unloading coupling assembly 120 to move into its initial position relative to the main body 110, and the unloading coupling assembly 120 is driven by the spool 200. The drive assembly 130 can rotate the spool 200 via the unloading coupling assembly 120 to retract the wire from the material guide tube and wind the wire around the spool 200, preventing the wire from getting stuck or accumulating. It also prevents the wire from wrapping around other components, allowing the multi-material unit to operate with high reliability under normal circumstances. Furthermore, the multi-material unit can also be more organized.

[0028] When the 3D printer needs to perform a printing operation, the drive assembly 130 can, for example, drive the unloading coupling assembly 120 to move into the second position relative to the main body 110, thus disconnecting the unloading coupling assembly 120 from the spool 200. The wire in the material guide tube can be continuously transported under the 3D printer's drive motor to the hot end (not shown) of the 3D printer. Since the unloading coupling assembly 120 is drive-disconnected from the spool 200, it does not impede the rotation of the spool 200. The spool 200 can rotate freely relative to the spool holder 400 under the wire drive, and the 3D printing system can normally print a three-dimensional object. Furthermore, the drive assembly 130 is not driven by the spool 200 during the printing operation, thus reducing unnecessary wear.

[0029] With further reference to Fig. 1. In this example, the coil 200 can comprise an intermediate body and flanges 210, each located on two sides of the intermediate body. The intermediate body can be configured to wind the wire, and the flanges 210 can each project circumferentially from the intermediate body, thereby blocking the wire and preventing it from being discharged from the coil 200.

[0030] With continued reference to the Fig. In some embodiments, the material feed mechanism 100 may further comprise a discharge friction wheel 150, rotatably connected to the main body 110. The discharge friction wheel 150 has a wheel surface for a frictional connection with the flanges 210 of the spool 200. When the discharge coupling assembly 120 is in the first position, it is driven by the discharge friction wheel 150 to rotate the spool 200 via the discharge friction wheel 150. When the discharge coupling assembly 120 is in the second position, it is driven by the discharge friction wheel 150, thus disconnecting it from the spool 200.

[0031] The discharge friction wheel 150 can have a wheel-like structure, the wheel surface of which may be knurled or otherwise textured. When the discharge coupling assembly 120 is in the first position, it can be drivenly connected to the discharge friction wheel 150, and the drive force of the drive assembly 130 can be transmitted via the discharge coupling assembly 120 to the discharge friction wheel 150 and, via the discharge friction wheel 150, to the flanges 210 to rotate the coil 200. Since the wheel surface of the discharge friction wheel 150 is knurled, a static frictional force between the wheel surface and the flanges 210 can be increased, thus effectively rotating the coil 200. This solution is simple in design and easy to implement.Furthermore, the force between the spool 200 and the material feed mechanism 100 is transmitted via the surface where the surface of the discharge friction wheel 150 is in contact with the flanges 210 of the spool 200, without requiring a complex design of the spool 200, and the spool 200 can be conveniently removed from the roll holder 400, which facilitates the replacement of the spool 200.

[0032] Fig. Figure 8 is a schematic structure diagram of the discharge coupling arrangement 120 in the material feed mechanism of Fig. 5; and Fig. Figure 9 is a schematic exploded view of the discharge coupling assembly 120 of Fig. 8. With further reference to the Fig. 5, Fig. 8 and Fig. 9 In some embodiments, the drive arrangement 130 may comprise a drive motor 131 connected to the main body 110 and a transmission shaft 132 driven by an output shaft of the drive motor 131. The discharge coupling arrangement 120 may comprise a first connecting element 121, a first gear 122, and a second gear 123.

[0033] The first gear 122 is mounted on the transmission shaft 132 and is positively engaged with it. This means that the first gear 122 can have a non-circular through-bore, and the transmission shaft 132 can have a mating section whose shape matches the non-circular through-bore. The mating section of the transmission shaft 132 can be fitted with a sleeve, allowing the first gear 122 to remain stationary relative to the transmission shaft 132. When the transmission shaft 132 rotates under the drive of the drive motor 131, the first gear 122 can rotate with it.

[0034] The first connecting element 121 can be located on one side of the first gear 122 in a direction of rotation of the first gear 122. The first connecting element 121 comprises a first end 1212, which is fitted onto the transmission shaft 132, and a second end 1213, which is opposite the first end 1212. The first connecting element 121 can be made of a conventional material such as metal or plastic. The first end 1212 of the first connecting element 121 can be provided with a first through-hole through which the transmission shaft 132 can pass.

[0035] The second gear 123 is rotatably connected to the second end 1213 of the first connecting element. In one example, the second end 1213 of the first connecting element 121 can be provided with a second through-hole, and a pivot shaft passes through the second gear 123 and the second through-hole to connect the second gear 123 to the first connecting element 121. In another example, the second end 1213 of the first connecting element 121 is integrally provided with a pivot shaft that passes through the second gear 123 to rotatably connect the second gear 123 to the first connecting element 121.

[0036] The first gear 122 is engaged with the second gear 123. From a positional perspective, the first gear 122 and the second gear 123 are located at opposite ends of the first connecting element 121, and the first connecting element 121 abuts the first gear 122. It should be noted that although the first end 1212 of the first connecting element 121 is fitted onto the transmission shaft 132, there is no direct connection between these two elements. The first connecting element 121 can be held relatively in place by pressure generated by the abutment against the first gear 122, and this pressure can cause a frictional force between the first connecting element 121 and the first gear 122. This allows the first connecting element 121 and the second gear 123 to pivot around the transmission shaft 132 as the transmission shaft 132 and the first gear 122 rotate.This means that the first gear 122, the second gear 123, and the first connecting element 121 can rotate as a unit with the rotation of the transmission shaft 132. Furthermore, if an external force is present, it can be used to overcome the frictional force between the first connecting element 121 and the first gear 122, allowing the first connecting element 121 and the second gear 123 to rotate as a unit relative to the first gear. In other words, the first connecting element 121 and the second gear 123 can pivot freely around the transmission shaft 132.

[0037] To enable the first gear 122 to bear against the first connecting element 121, the transmission shaft 132 can be provided with two shoulders, each of which can have a diameter larger than that of the transmission shaft 132. The two shoulders can each be located on opposite sides of the discharge coupling assembly 120 in the axial direction of the transmission shaft 132, with the first connecting element 121 bearing against one of the shoulders and the first gear 122 bearing against the other shoulder. By rationally adjusting the distance between the two shoulders, the first connecting element 121 can bear against the first gear 122.

[0038] In one example, the discharge friction wheel 150 can comprise a first wheel body and a second wheel body arranged one behind the other in the axial direction of the discharge friction wheel 150, so that the second gear 123 can drive the discharge friction wheel 150 to rotate. The first wheel body and the second wheel body can be machined and formed in one piece. The first wheel body has a knurled wheel surface, and the second wheel body can have a plurality of circumferentially arranged teeth. The second wheel body can be configured to mesh with the second gear 123.

[0039] With reference to the Fig. 6 and Fig. 8. When the 3D printer has completed the printing process or a wire change is required, the drive motor 131 drives the transmission shaft 132 to rotate in a first direction (arrow direction in). Fig. 6) to rotate, thereby rotating the first connecting element 121, the first gear 122, and the second gear 123 as a whole relative to the main body 110, so that the second gear 123 of the discharge friction wheel body of the discharge friction wheel 150 can pivot into a position where it can engage with the second gear body of the discharge friction wheel 150, i.e., the discharge coupling assembly 120 is in the first position. Since the discharge friction wheel 150 is engaged with the second gear 123, the discharge friction wheel 150 exerts resistance to the rotation of the second gear body 122 and the first connecting element 121 in the circumferential direction of the transmission shaft 132 when the drive motor 131 continues to rotate the transmission shaft 132 in the first direction.This resistance can overcome the frictional force between the first connecting element 121 and the first gear 122, so that a relative rotation occurs between the first gear 122 and the first connecting element 121. That is, the first gear 122 can continue to rotate with the transmission shaft 132, while the first connecting element 121 can remain stationary relative to the main body 110. Since the first gear 122 is engaged with the second gear 123, the first gear 122 can rotate with the transmission shaft 132 to drive the second gear 123 to rotate relative to the first connecting element 121, while the second gear 123 can drive the discharge friction wheel 150 via the second wheel body to rotate, and then drive the coil 200 to rotate.According to the solution, the structure is simple; the discharge coupling assembly 120 can be moved between the first and second positions by a drive motor 131, thus reducing costs. With reference to the... Fig. 5 and Fig. 7, when the drive motor 131 drives the transmission shaft 132 to rotate in a second direction opposite to the first direction, the second gear 123 can be drivenly separated from the second wheel body, and the discharge coupling arrangement 120 is in the second position.

[0040] In the embodiment described above, the discharge friction wheel 150 comprises the first wheel body, which is configured to be driven by the coil 200, and the second wheel body, which is configured to be driven by the discharge coupling arrangement 120. In further embodiments, the material feed mechanism 100 may also comprise a first mating gear 151, which is coaxially connected to the discharge friction wheel 150, as shown in Fig. 5 shown. For example, the main body 110 can be provided with a rotatable relief rotary shaft, and the first counter gear 151 and the discharge friction wheel 150 can both be positively connected to the relief rotary shaft, so that the machining of the discharge friction wheel 150 can be simplified and the costs reduced.

[0041] The first mating gear 151 is configured such that, when the discharge coupling assembly 120 is in the first position, the first mating gear 151 is engaged with the second gear 123 of the discharge coupling assembly 120. The second gear 123 can rotate the first mating gear 151 and then rotate the discharge friction gear 150. When the discharge coupling assembly 120 is in the second position, the first mating gear 151 is disengaged from the second gear 123 of the discharge coupling assembly 120.

[0042] In some embodiments, the discharge coupling arrangement 120 further comprises a second connecting element 124, which is arranged in relation to the first gear 122 and the second gear 123 opposite the first connecting element 121 ().

[0043] With further reference to the Fig. 8 and Fig. 9. The first connecting element 121 and the second connecting element 124 can each be arranged on two sides of the first gear 122 and the second gear 123 in the axial direction of the transmission shaft 132. The two sides of the first gear 122 can each bear against the first connecting element 121 and the second connecting element 124.

[0044] The second connecting element 124 can also be attached to the transmission shaft 132, with particular reference to a type of connection between the first end 1212 of the first connecting element 121 and the transmission shaft 132.

[0045] In one example, the second end 1213 of the first connecting element 121 is integrally provided with a rotating shaft, the second connecting element 124 is provided with a shaft bore at a corresponding position, and the rotating shaft runs through the second gear 123 and the shaft bore to rotatably connect the second gear 123 between the first connecting element 121 and the second connecting element 124. In another example, the second connecting element 124 is provided with a rotating shaft, the first connecting element 121 is provided with a shaft bore, and the rotating shaft runs through the second gear 123 and the shaft bore.

[0046] The discharge coupling assembly 120 can include an elastic clamping element 125. The elastic clamping element 125 bridges the first connecting element 121 and the second connecting element 124 to provide an elastic force that enables the first connecting element 121 and the second connecting element 124 to clamp the first gear 122. The elastic clamping element 125 can continuously provide the elastic force to improve the reliability of the discharge coupling assembly 120.

[0047] Various structures of the elastic clamping element 125 are possible. For example, the elastic clamping element 125 can include a spring, one end of which is connected to the first connecting element 121 and the other end of which is connected to the second connecting element 124. The spring can provide a tensile force so that the first connecting element 121 and the second connecting element 124 clamp the first gear 122.

[0048] As a further example, the elastic clamping element 125 comprises an elastic clamping element body 1251, which extends axially parallel to the transmission shaft 132, and two clamping jaws, each connected to two ends of the elastic clamping element body 1251. For the sake of simplicity, the two clamping jaws are referred to as the first clamping jaw 1252 and the second clamping jaw 1253. The first clamping jaw 1252 abuts an outer surface of the first connecting element 121 that faces away from the first gear 122 and the second gear 123, and the second clamping jaw 1253 abuts an outer surface of the second connecting element 124 that faces away from the first gear 122 and the second gear 123.

[0049] The distance between the first clamping jaw 1252 and the second clamping jaw 1253 can be smaller than the distance between the outer surface of the first connecting element 121 and the outer surface of the second connecting element 124. This allows the elastic clamping element 125 to bridge the first connecting element 121 and the second connecting element 124, enabling the first clamping jaw 1252 and the second clamping jaw 1253 to deform elastically relative to the elastic clamping element body 1251. This deformation increases the distance between them, thereby providing the elastic force needed to clamp the first connecting element 121 and the second connecting element 124. Furthermore, the first clamping jaw 1252, the second clamping jaw 1253, and the elastic clamping element 1251 can all be positioned opposite or near the first connecting element 121 and the second connecting element 124, thus reducing the volume of the discharge coupling assembly 120.

[0050] In one example, the outer surface of the first connecting element 121 is provided with a first groove 1211, and the outer surface of the second connecting element 124 is provided with a second groove 1241. The first clamping jaw 1252 is provided with a first projection 1252a that engages in the first groove 1211, and the second clamping jaw 1253 is provided with a second projection 1253a that engages in the second groove 1241. This improves the contact area between the first connecting element 121 and the first clamping jaw 1252, as well as between the second connecting element 124 and the second clamping jaw 1253, so that the elastic clamping element 125 does not tend to detach from the first connecting element 121 and the second connecting element 124, thereby improving the reliability of the discharge coupling arrangement 120.

[0051] In some embodiments, the main body 110 can also be provided with a first position limiter 111 and a second position limiter 112. The discharge coupling assembly 120 is movable between the first position limiter 111 and the second position limiter 112. The first position limiter 111 and the second position limiter 112 can both be configured to protrude from the main body 110. For example, the first position limiter 111 can comprise a bolt, wherein a threaded section of the bolt can be screwed into a threaded hole in the main body 110 and a head section of the bolt can be arranged outside the threaded hole.

[0052] The first position limiter 111 is positioned on a movement path of the discharge coupling assembly 120 relative to the main body 110 such that the discharge coupling assembly 120 is in the first position when it is moved against the first position limiter 111. With reference to the Fig. 6 and Fig. In section 8, the first position limiter 111 is arranged with respect to the second end 1213 of the second connecting element 124 of the discharge coupling assembly 120 such that, when the discharge coupling assembly 120 is in the first position, an upper edge of the second end 1213 of the second connecting element 124 can bear against the first position limiter 111. The first position limiter 111 can provide resistance to the frictional force between the first connecting element 121 and the first gear 122, so that the discharge coupling assembly 120 can remain in the first position. The first position limiter 111 also makes it possible to reduce the contact force between the second gear 123 and the first mating gear 151, thereby reducing wear on both gears and extending the service life of the discharge coupling assembly 120.

[0053] The second position limiter 112 is positioned on a movement path of the discharge coupling assembly 120 relative to the main body 110 such that the discharge coupling assembly 120 is in the second position when it is moved against the second position limiter 112. With reference to the Fig. 7 and Fig. In section 8, the second position limiter 112 is arranged with respect to the second end 1213 of the second connecting element 124 of the discharge coupling assembly 120 such that, when the discharge coupling assembly 120 is in the second position, a lower edge of the second end 1213 of the second connecting element 124 can bear against the second position limiter 112. The second position limiter 112 can provide resistance to the frictional force between the first connecting element 121 and the first gear 122, so that when the transmission shaft 132 continues to rotate in the second direction, the discharge coupling assembly 120 can remain in the second position, thereby shortening the travel distance of the discharge coupling assembly 120 and reducing unnecessary movement of the discharge coupling assembly 120.

[0054] It should be noted that the amount by which the first position limiter 111 and the second position limiter 112 protrude from the main body 110 is larger than the gap between the second connecting element 124 and the main body 110, but smaller than the gap between the second gear 123 and the main body 110. In this way, the first position limiter 111 and the second position limiter 112 can play a limiting role without, however, affecting the normal rotation of the second gear 123.

[0055] The functions of the first position limiter 111 and the second position limiter 112 are described above using an example in which the second connecting element 124 of the discharge coupling assembly 120 is located between the first connecting element 121 and the main body 110 (as in Fig. 5 shown). In some embodiments, the first connecting element 121 can be located between the second connecting element 124 and the main body 110, and the first position limiter 111 and the second position limiter 112 can then be configured to abut an upper edge and a lower edge, respectively, of the first connecting element 121. The spatial terms “upper” and “lower” are used here in relation to the Fig. 6 and Fig. 7 are used and should not be interpreted as restrictive.

[0056] Fig. Figure 10 is a schematic structure diagram of the material feeding mechanism. Fig. 5, with the main body 110 removed; Fig. Figure 11 is an axonometric view of the material feeding mechanism 100. Fig. 4 at a second angle; Fig. Figure 12 is a schematic structure diagram of the material feeding mechanism. Fig. 11, with one wire support frame removed; Fig. Figure 13 is a schematic structure diagram of a loading coupling arrangement 140 in the material feeding mechanism of Fig. 12 in a third position; and Fig. Figure 14 is a schematic structure diagram of the loading coupling arrangement 140 in the material feed mechanism of Fig. 12 in a fourth position. The arrow direction in Fig. 13 is the first direction.

[0057] With reference to the Fig. In some embodiments, the material feed mechanism 100 further comprises a loading coupling arrangement 140. The loading coupling arrangement 140 is connected to the main body 110. Under the drive of the drive arrangement 130, the loading coupling arrangement 140 can be moved between a third position relative to the main body 110 (which is shown in the following description): Fig. 13 position shown) and a fourth position relative to the main body 110 (which is shown in Fig. 14 (position shown) can be switched.

[0058] When the loading coupling arrangement 140 is in the third position, the loading coupling arrangement 140 can be drive-disconnected from a wire 300, i.e. the drive force of the drive arrangement 130 cannot be transmitted to the wire 300.

[0059] When the loading coupling arrangement 140 is in the fourth position, the loading coupling arrangement 140 is drivenly coupled to the wire 300, and the loading coupling arrangement 140 can transmit the driving force delivered by the drive arrangement 130 to the wire 300 in order to pull the wire 300 from the spool 200 by driving the drive arrangement 130.

[0060] In one example, the main body 100 can be provided with a wire support frame 115. The wire 300 is wound around the coil 200, and the end of the wire 300 can protrude from the coil 200 and rest on the wire support frame 115. To fully illustrate the structure of the material feeding mechanism 100, the wire wound around the coil 200 is not shown in the drawings.

[0061] When the 3D printer needs to print a three-dimensional object, the drive assembly 130 drives the loading coupling assembly 140 to move into the fourth position relative to the main body 110, and the loading coupling assembly 140 is drivenly coupled to the wire 300 so that the wire 300 can be pulled to convey the wire 300 into the material guide tube.

[0062] The drive assembly 130 can then, for example, drive the loading coupling assembly 140 to move into the third position relative to the main body 110, and the loading coupling assembly 140 is thus disconnected from the wire 300. In this way, the 3D printer's print motor can pull the wire 300 into the material guide tube and perform the printing process. The drive assembly 130 does not need to provide any drive force in this process, thus saving energy. Since the loading coupling assembly 140 is disconnected from the wire 300, the drive force for pulling the wire 300 from the drive motor is also prevented from being transferred to the drive assembly 130, thereby reducing the load on the drive motor. Furthermore, the drive assembly 130 is not driven by the wire 300 during the printing process, thus reducing unnecessary wear.

[0063] The loading coupling assembly 140 can be driven in various ways. For example, the drive assembly 130 can include a first motor to drive the loading coupling assembly 140 to move between the third position and the fourth position, and a second motor to drive the unloading coupling assembly 120 to move between the first position and the second position.

[0064] In further embodiments, the loading coupling arrangement 140 and the unloading coupling arrangement 120 can be driven using the same drive motor 131. The unloading coupling arrangement 120 and the loading coupling arrangement 140 are each provided with a sleeve at two ends of the transmission shaft 132, and the output shaft of the drive motor 131 is drivenly coupled to a section of the transmission shaft 132 between the unloading coupling arrangement 120 and the loading coupling arrangement 140.

[0065] In one embodiment, the main body 110 can have a first wall surface 116 ( Fig. 5) and a second wall surface 117 ( Fig. 12) which are arranged opposite each other. The drive motor 131 can be arranged between the first wall surface 116 and the second wall surface 117, and the transmission shaft 132 can penetrate both the first wall surface 116 and the second wall surface 117. As shown in Fig. As shown in Figure 10, the output shaft of the drive motor 131 can be coaxially equipped with a worm 135, and the section of the transmission shaft 132 between the first wall surface 116 and the second wall surface 117 can be encased with a worm gear 134. The worm gear 134 interacts with the worm 135 so that the direction of a torque delivered by the drive motor 131 can be changed, thus simplifying the structure of the material feeding mechanism 100.

[0066] With reference to Fig. 5. A first end section of the transmission shaft 132, extending beyond the first wall surface 116, can be connected to the discharge coupling arrangement 120. With reference to Fig. 12 A second end section of the transmission shaft 132, extending beyond the second wall surface 117, can be connected to the loading coupling assembly 140. To prevent the unloading coupling assembly 120 and the loading coupling assembly 140 from shifting axially along the transmission shaft 132, locking devices 133 can also be provided on the transmission shaft 132. The side of the loading coupling assembly 140 facing away from the main body 110 is provided with a locking device 133, and the side of the unloading coupling assembly 120 facing away from the main body 110 can also be provided with a locking device 133.

[0067] With reference to Fig. In some embodiments, the material feeding mechanism 100 further comprises a loading friction wheel 160, which is rotatably connected to the main body 110. The loading friction wheel 160 has a wheel surface for a frictional connection with the wire 300. When the loading coupling assembly 140 is in the third position, the loading coupling assembly 140 is disengaged from the loading friction wheel 160, so that the loading coupling assembly 140 is disengaged from the wire 300. When the loading coupling assembly 140 is in the fourth position, the loading coupling assembly 140 is engaged with the loading friction wheel 160 to draw the wire 300 through the loading friction wheel 160.

[0068] With reference to Fig. 11. The loading friction wheel 160 can have a wheel-like structure, the wheel surface being provided with knurling or other structures. The wheel surface of the loading friction wheel 160 can be configured to come into contact with the wire 300, thereby driving the wire 300 to move in a tangential direction to the loading friction wheel 160. In one example, the wire 300 can be located between the wheel surface of the loading friction wheel 160 and the wire support frame 115, and the loading friction wheel 160 can drive the wire 300 to slide along a surface of the wire support frame 115. In another example, the main body 110 can be provided with a rotatable driven friction wheel, and the wire 300 can be arranged between the wheel surface of the loading friction wheel 160 and a wheel surface of the driven friction wheel.When the loading friction wheel 160 rotates, the driven friction wheel rotates with the loading friction wheel 160 to pull the wire 300, so that the frictional force between the wire 300 and the loading friction wheel 160 or the driven friction wheel is a rolling friction force and the wire 300 can be pulled more easily.

[0069] When the loading coupling assembly 140 is in the fourth position, it can be driven by the loading friction wheel 160. The drive force from the drive assembly 130 can be transmitted via the loading coupling assembly 140 to the loading friction wheel 160, and from there to the wire 300, thus driving the wire 300. Since the wheel surface of the loading friction wheel 160 is knurled, the static frictional force between the wheel surface and the wire 300 can be increased, effectively driving the wire 300 to move. This solution is simple in structure, easy to implement, and reduces production costs.

[0070] There are various versions of the loading coupling assembly 140. In some embodiments, the loading coupling assembly 140 is structurally identical to the unloading coupling assembly 120; however, the functions of the two assemblies differ in that the loading coupling assembly 140, when in the fourth position, is drivenly coupled to the wire 300, while the unloading coupling assembly 120, when in the first position, is drivenly coupled to the coil 200. That is, the structures to which the unloading coupling assembly 120 and the loading coupling assembly 140 are drivenly coupled are different.

[0071] For example, the loading coupling arrangement 140 can also comprise a first connecting element, a first gear, and a second gear. The first connecting element comprises a first end that is mounted on the transmission shaft 132 and a second end that is opposite the first end. The first gear is mounted on the transmission shaft 132 and is positively engaged with the transmission shaft 132. The second gear is rotatably connected to the second end of the first connecting element and engages with the first gear. The first connecting element abuts the first gear, so that the first connecting element and the second gear can pivot around the transmission shaft 132 with the rotation of the transmission shaft 132 and the first gear.

[0072] In one example, the loading coupling arrangement 140 further comprises a second connecting element which is arranged in relation to the first gear and the second gear in relation to the first connecting element.

[0073] In one example, the loading coupling arrangement 140 further comprises an elastic clamping element for bridging the first connecting element and the second connecting element in order to provide an elastic force that enables the first connecting element and the second connecting element to clamp the first gear.

[0074] As an example of an embodiment of the elastic clamping element of the loading coupling arrangement 140, the elastic clamping element comprises an elastic clamping element body extending axially parallel to the transmission shaft 132, and two clamping jaws, each connected to two ends of the elastic clamping element body. A first clamping jaw of the two clamping jaws abuts an outer surface of the first connecting element that faces away from the first gear and the second gear, and a second clamping jaw of the two clamping jaws abuts an outer surface of the second connecting element that faces away from the first gear and the second gear.

[0075] Furthermore, in the loading coupling arrangement 140, the outer surface of the first connecting element can be provided with a first groove, and the outer surface of the second connecting element can be provided with a second groove. The first clamping jaw is provided with a first projection that engages in the first groove, and the second clamping jaw is provided with a second projection that engages in the second groove.

[0076] The first connecting element, the first gear, the second gear, the elastic clamping element and the second connecting element in the loading coupling arrangement 140 are identical in structure and function to the first connecting element 121, the first gear 122, the second gear 123, the elastic clamping element 125 and the second connecting element 124 in the unloading coupling arrangement 120, and special reference can be made to the above description of the unloading coupling arrangement 120, which is not described again in detail here.

[0077] In some embodiments, the second gear of the loading coupling assembly 140 can drive the loading friction wheel 160 to rotate, the loading friction wheel 160 comprising a third wheel body and a fourth wheel body. The third and fourth wheel bodies can be integrally machined and formed. The third wheel body has a knurled wheel surface, and the fourth wheel body can have a plurality of circumferentially arranged teeth. The fourth wheel body can be configured to mesh with the second gear 123.

[0078] In other embodiments, the material feed mechanism 100 can include a second counter gear 161. The second counter gear 161 is coaxially connected to the loading friction gear 160, as shown in Fig. Figure 11 shows. For example, the main body 110 can be provided with a rotatable loading shaft, and the second counter gear 161 and the loading friction gear 160 can both be positively connected to the loading shaft, thus simplifying the machining of the loading friction gear 160 and reducing costs.

[0079] The second mating gear 161 is configured such that when the loading coupling assembly 140 is in the third position, the second mating gear 161 is disengaged from the second gear of the loading coupling assembly 140, and when the loading coupling assembly 140 is in the fourth position, the second mating gear 161 is engaged with the second gear of the loading coupling assembly 140, and the second gear can rotate the second mating gear 161, thereby rotating the loading friction gear 160 ().

[0080] With reference to Fig. 14. When the 3D printer needs to print a three-dimensional object, the drive motor 131 drives the transmission shaft 132 to move in a second direction (opposite the direction of the arrow in the Fig. 13) to rotate the first connecting element, the first gear, and the second gear of the loading coupling assembly 140 as a whole relative to the main body 110, so that the second gear can swing into a position where it can engage with the second mating gear 161, i.e., the loading coupling assembly 140 is in the fourth position. Since the second mating gear 161 is engaged with the second gear, the second mating gear 161 exerts resistance to the rotation of the second gear and the first connecting element in the circumferential direction of the transmission shaft 132 when the drive motor 131 continues to rotate the transmission shaft 132 in the second direction. The resistance can overcome a frictional force between the first connecting element and the first gear, so that a relative rotation occurs between the first gear and the first connecting element.This means that the first gear can continue to rotate with the transmission shaft 132, while the first connecting element can remain stationary relative to the main body 110. Since the first gear is meshed with the second gear, the first gear can drive the second gear to rotate relative to the first connecting element, while the second gear can drive the second mating gear 161 to rotate, thereby driving the loading friction gear 160 to rotate in order to feed the wire 300 in a right-to-left direction. Fig. 14 (i.e. in Fig. 11. The wire 300 moves in the direction of the arrow) to pull it into the material guide tube. After the wire 300 has been fed into the material guide tube, the drive motor 131 can, for example, drive the transmission shaft 132 to move in the first direction (the direction of the arrow in the direction of the arrow). Fig. 13) to rotate, the second gear of the loading coupling assembly 140 can be disengaged from the second mating gear 161, and the loading coupling assembly 140 is in the third position (as in Fig. (shown in Figure 13). In this way, the 3D printer's print motor can continue to pull the wire in the material guide tube to carry out the printing process.

[0081] In some embodiments, the unloading coupling arrangement 120 and the loading coupling arrangement 140 are configured such that the loading coupling arrangement 140 is in the third position when the unloading coupling arrangement 120 is in the first position, and that the loading coupling arrangement 140 is in the fourth position when the unloading coupling arrangement 120 is in the second position.

[0082] During an unloading process, the unloading coupling assembly 120 is located in the Fig. 6 shown position and the loading coupling arrangement 140 in the in Fig. 13. During a charging process, the unloading coupling assembly 120 is located in the position shown in Fig. 7 shown position and the loading coupling arrangement 140 in the in Fig. Position 14 shown.

[0083] When the 3D printer has completed the printing process or a wire change is required, the drive assembly 130 drives the unloading clutch assembly 120 to engage it with the unloading friction wheel 150 and drives the loading clutch assembly 140 to disengage it from the loading friction wheel 160. The unloading friction wheel 150 can then drive the spool 200 to reverse rotation, thereby winding the wire around the spool 200. During this process, the loading clutch assembly 140 is disengaged from the loading friction wheel 160 and does not impede the reverse rotation of the spool 200.

[0084] When the 3D printer needs to print a three-dimensional object, the drive assembly 130 drives the loading coupling assembly 140 to engage with the loading friction wheel 160 and drives the unloading coupling assembly 120 to disengage from the unloading friction wheel 150. The loading friction wheel 160 can then pull the wire 300 into the material guide tube. During this process, the spool 200 rotates forward relative to the spool holder 400, and the unloading coupling assembly 120 does not impede the forward rotation of the spool 200.

[0085] It should be noted that in some embodiments the drive arrangement 130 can be implemented by arranging a first motor and a second motor to drive the loading coupling arrangement 140 and the unloading coupling arrangement 120 respectively, and in some embodiments it can be implemented by the drive motor 131 and the transmission shaft 132.

[0086] In one example, the unloading coupling arrangement 120 and the loading coupling arrangement 140 are mounted on the transmission shaft 132 in such a way that the unloading coupling arrangement 120 and the loading coupling arrangement 140 can be pivoted around the transmission shaft 132 by rotating the transmission shaft 132.The unloading coupling assembly 120 and the loading coupling assembly 140 are positioned at an angle to each other in the circumferential direction of the transmission shaft 132, such that when the unloading coupling assembly 120 is pivoted circumferentially around the transmission shaft 132 in the first direction to the first position, the loading coupling assembly 140 is pivoted in the first direction to the third position; and when the unloading coupling assembly 120 is pivoted around the transmission shaft 132 in a second direction opposite to the first direction to the second position, the loading coupling assembly 140 is pivoted in the second direction to the fourth position. Therefore, a drive motor 131 can be provided, which simplifies the structure of the material feeding mechanism 100.

[0087] In some embodiments, the main body 110 of the material feed mechanism 100 is further provided with a third position limiter 113 and a fourth position limiter 114. The loading coupling assembly 140 is movable between the third position limiter 113 and the fourth position limiter 114.

[0088] The third position limiter 113 and the fourth position limiter 114 can both be configured to protrude from the main body 110, and the structure of the first position limiter 111 can be referenced for the specific implementation. In one example, the first position limiter 111 and the second position limiter 112 protrude from the first wall surface 116 of the main body 110, and the third position limiter 113 and the fourth position limiter 114 protrude from the second wall surface 117 of the main body 110.

[0089] The third position limiter 113 is positioned on a movement path of the loading coupling assembly 140 relative to the main body 110 such that the loading coupling assembly 140 is in the third position when it is moved against the third position limiter 113. The fourth position limiter 114 is positioned on a movement path of the loading coupling assembly 140 relative to the main body 110 such that the loading coupling assembly 140 is in the fourth position when it is moved against the fourth position limiter 114. With reference to Fig. The third position limiter 113 is arranged with respect to the second end (the smaller of the two ends of the second connecting element) of the second connecting element (the one of the two connecting elements of the loading coupling assembly 140 that is closer to the main body 110) of the loading coupling assembly 140, such that when the loading coupling assembly 140 is in the third position, a left edge of the second end of the second connecting element can abut the third position limiter 113. The fourth position limiter 114 is arranged relative to the third position limiter 113 with respect to the second end of the second connecting element of the loading coupling assembly 140, such that when the loading coupling assembly 140 is in the fourth position, a right edge of the second end of the second connecting element can abut the third position limiter 113. The spatial terms "left" and "right" are used here in relation to the Fig. 13 and Fig. 14 are used and are not to be understood as restrictive.

[0090] The following is an example in which the reverse rotation of the drive motor 131 causes the transmission shaft 132 to rotate in the first direction, and the forward rotation of the drive motor 131 causes the transmission shaft 132 to rotate in the second direction. Referring to the Fig. 6 and Fig. When the drive motor 131 reverses the unloading coupling assembly 120 to engage with the unloading friction wheel 150, the unloading coupling assembly 120 may collide with the first position limiter 111, and the loading coupling assembly 140 may collide with the third position limiter 113. If the drive motor 131 continues to reverse to rotate the coil 200, the transmission shaft 132 continues to rotate in the first direction, and the third position limiter 113 can provide resistance to the frictional force between the first connecting element and the first gear of the loading coupling assembly 140, thus holding the loading coupling assembly 140 in the third position. This can shorten the travel distance of the loading coupling assembly 140 and reduce unnecessary movement of the loading coupling assembly 140.

[0091] With reference to Fig. When the drive motor 131 rotates forward to drive the loading coupling assembly 140, so that it is drivenly coupled to the loading friction wheel 160, the loading coupling assembly 140 can be in contact with the fourth position limiter 114, and the unloading coupling assembly 120 can be in contact with the second position limiter 112. If the drive motor 131 continues to rotate forward, the fourth position limiter 114 can exert resistance against the frictional force between the first connecting element and the first gear of the loading coupling assembly 140, so that the loading coupling assembly 140 can remain in the fourth position and the drive motor 131 can pull the wire 300 through the loading friction wheel 160.By arranging the fourth position limiter 114, the contact force between the second gear and the second mating gear 161 can be reduced, the wear of the two gears can be reduced, and the service life of the loading coupling assembly 140 can be extended. Furthermore, the second position limiter 112 can provide resistance to the frictional force between the first connecting element 121 and the first gear 122 of the unloading coupling assembly 120, so that the unloading coupling assembly 120 can remain in the second position.

[0092] The specific limiting method of the third position limiter 113 and the fourth position limiter 114 can refer to the above description of the first position limiter 111 and the second position limiter 112 and is not described again in detail here.

[0093] One embodiment of the present disclosure further provides a multi-material unit comprising at least one coil 200 and at least one material feed mechanism 100. At least one wire 300 for a 3D printer is wound around each of the at least one coil 200. The at least one material feed mechanism 100 is used with each of the at least one coil 200 to feed at least one wire 300 to the 3D printer.

[0094] It should be noted that the multi-material unit can comprise a housing and at least one (or more) material feed module(s) arranged within the housing, and that each material feed module can be equipped with a spool 200 and a material feed mechanism 100. That is, the material feed mechanisms 100 and the spools 200 in the multi-material unit are numbered one-to-one, and a spool 200 can be wound with a wire 300 and equipped with a material feed mechanism 100. In an example, each spool 200 can further be equipped with a spool holder 400. Additionally, a material guide tube for guiding the wire to the hot end of the 3D printer can penetrate the housing of the multi-material unit; that is, several material feed units can share a single material guide tube.

[0095] The design and function of the material feed mechanism 100 correspond to those of the embodiment above and are not described again in detail here.

[0096] One embodiment of the present disclosure further provides a 3D printing system comprising a 3D printer and a multi-material unit. The multi-material unit is configured to feed a wire 300 to the 3D printer. The 3D printer has a hot end and a print motor, and the print motor can be configured to pull the wire 300 in a material guide tube and convey it to the hot end during printing. The hot end can heat and melt the wire 300, and the 3D printer can build a three-dimensional object layer by layer with a build material formed after the wire is melted.

[0097] As described above, the multi-material unit can comprise at least one spool 200 and at least one material feed mechanism 100. At least one wire 300 for a 3D printer is wound around each of the at least one spool 200. The at least one material feed mechanism 100 is intended for use with the respective 200 of the at least one spool 200 to feed at least one wire 300 to the 3D printer.

[0098] As described above, each material feeding mechanism 100 comprises a main body 110, a discharge coupling assembly 120 connected to the main body 110, and a drive assembly 130. The drive assembly 130 is configured to drive the discharge coupling assembly 120 so that it is switchable between a first position relative to the main body 110, in which the discharge coupling assembly 120 is drivenly coupled to a corresponding coil 200 of the at least one coil 200 in order to rotate the corresponding coil 200 under the drive of the drive assembly 130 in order to wind the corresponding wire 300 of the at least one wire 300 around the corresponding coil 200; and a second position relative to the main body 110, in which the discharge coupling assembly 120 is drivenly disconnected from the corresponding coil 200.

[0099] In some embodiments, each material feed mechanism 100 further comprises a loading coupling arrangement 140 connected to the main body 110. The drive arrangement 130 is further configured to drive the loading coupling arrangement 140 so that it is switchable between a third position relative to the main body 110, in which the loading coupling arrangement 140 is drive-disconnected from the corresponding wire 300, and a fourth position relative to the main body 110, in which the loading coupling arrangement 140 is drive-coupled to the corresponding wire 300 in order to draw the corresponding wire 300 from the corresponding spool 200 by driving the drive arrangement 130.

[0100] The specific structure and function of the multi-material unit and the material feed mechanism 100 can refer to the above embodiments and will not be described again in detail here.

[0101] In some embodiments, in each material feed mechanism 100 of the multi-material unit of the 3D printing system, the drive arrangement 130 can also be configured to perform the following operations.

[0102] When the material feed mechanism 100 is actuated for unloading, the drive arrangement 130 drives the unloading coupling arrangement 120 to move into the first position and drives the loading coupling arrangement 140 to move into the third position.

[0103] The "unloading" can occur when the printing process is complete or a wire change is required, which can be understood as a process in which the wire 300 must be pulled out of the material guide tube and rewound around the spool 200. During unloading, the drive assembly 130 drives the unloading coupling assembly 120 to engage with the unloading friction wheel 150 and drives the loading coupling assembly 140 to disengage from the loading friction wheel 160. The unloading friction wheel 150 can then drive the spool 200 to rotate backward, thereby winding the wire around the spool 200. During this process, the loading coupling assembly 140 is disengaged from the loading friction wheel 160 and does not impede the reverse rotation of the spool 200.

[0104] When the material feed mechanism 100 is actuated for loading, the drive assembly 130 drives the unloading coupling assembly 120 to move into the second position and drives the unloading coupling assembly 140 to move into the fourth position.

[0105] "Loading" can be understood as a process in which the multi-material unit supplies the wire 300 required for printing to the material guide tube. During loading, the drive assembly 130 drives the loading clutch assembly 140 to engage with the loading friction wheel 160 and drives the unloading clutch assembly 120 to disengage with the unloading friction wheel 150. The loading friction wheel 160 can draw the wire 300 into the material guide tube, and during the drawing of the wire 300, the spool 200 rotates forward relative to the reel holder 400, and the unloading clutch assembly 120 does not impede the forward rotation of the spool 200.

[0106] When the material feed mechanism 100 has been activated for loading so that the 3D printer can perform the printing process, the drive assembly 130 holds the unloading coupling assembly 120 in the second position, holds the loading coupling assembly 140 in the fourth position and switches off the drive assembly 130.

[0107] "Printing" can be understood as a process in which the print motor in the 3D printer pulls the wire 300 in the material guide tube and transports it to the hot end of the 3D printer. During the printing process, the drive assembly 130 can drive the loading coupling assembly 140 to engage it with the loading friction wheel 160, and drive the unloading coupling assembly 120 to disengage it from the unloading friction wheel 150, and then stop the drive assembly 130, for example, by switching off the power supply to the drive motor 131. With reference to the Fig. 11 and Fig. 14. The wire 300 can continue to move in the direction of the arrow through the drive motor. Fig. 11 (in Fig. 14 from right to left), and the driving force exerted by the drive motor on the wire 300 can simultaneously drive the loading friction wheel 160, moving clockwise in Fig. 14 to turn, and then drive the coaxial second counter gear 161, moving clockwise in Fig.The second counter gear 161 can exert a driving force on the second gear of the loading coupling assembly 140, causing it to rotate counterclockwise relative to the transmission shaft 132. This pushes the second gear away, disengaging the loading coupling assembly 140 from the second counter gear 161 and allowing it to be positioned between the third and fourth positions. Since the drive assembly 130 has ceased operation, the transmission shaft 132 does not rotate, and the unloading coupling assembly 120 can remain in the second position. The 3D printer can continue printing, and neither the loading coupling assembly 140 nor the unloading coupling assembly 120 interferes with the normal operation of the printer motor.

[0108] It should be noted that during the printing process, the loading coupling assembly 140 can be located between the third position, defined by the third position limiter 113, and the fourth position, defined by the fourth position limiter 114, after it has been pushed away. When the 3D printing system resumes unloading, the loading coupling assembly 140, together with the transmission shaft 132, can rotate in the first direction and be moved into the third position, with the unloading coupling assembly 120 moving from the second position to a position between the first and second positions at this time. If the transmission shaft 132 continues to rotate in the first direction, the unloading coupling assembly 120 can again collide with the position limiter 111 for the first position, i.e., the unloading coupling assembly 120 is in the first position.The transmission shaft 132 continues to rotate in the first direction and drives the coil 200 via the discharge coupling arrangement 120 to a reverse rotation in order to wind the wire 300 around the coil 200.

[0109] Similarly, when the 3D printing system resumes loading, the loading coupling assembly 140, along with the transmission shaft 132, can rotate in the second direction and be brought into the fourth position. At this point, the unloading coupling assembly 120 may be located between the first and second positions. As the transmission shaft 132 continues to rotate in the second direction to pull the wire 300 for loading, the unloading coupling assembly 120 can again engage the position limiter 112 for the second position, i.e., be in the second position.

[0110] In some embodiments, the unloading coupling arrangement 120 can also be located between the first and second positions during the printing process, and the loading coupling arrangement 140 can be located between the third and fourth positions by adjusting the rotation angle of the drive motor 131. The specific angle can be adjusted according to the actual situation.

[0111] According to the multi-material unit and the 3D printing system provided by the embodiments of the present disclosure, the unloading coupling arrangement 120 and the drive arrangement are arranged on the main body 110 of the material feed mechanism 100 such that the drive arrangement 130 can drive the unloading coupling arrangement 120 to switch between the first position relative to the main body 110 and the second position relative to the main body 110. In the first position, the unloading coupling arrangement 120 is drivenly coupled to the coil 200 and can rotate the coil 200 under the drive of the drive arrangement 130 to wind the wire 300 around the coil 200, thereby preventing the wire 300 from getting stuck or accumulating in the material feed mechanism 100 after unloading and thus improving the reliability and orderliness of the multi-material unit.In the second position, the discharge coupling arrangement 120 is drive-wise separated from the coil 200, and the 3D printing system can normally print a three-dimensional object.

[0112] The following embodiments are provided by this application. It should be noted that the numbering of the following embodiments does not necessarily have to follow the numbering sequence of the previous embodiments. Embodiment 1: A material feeding mechanism 100 comprising: a main body 110; a discharge coupling arrangement 120 connected to the main body 110; and a drive arrangement 130 configured to drive the discharge coupling arrangement 120 so that it is switchable between (i) a first position relative to the main body 110 in which the discharge coupling arrangement 120 is drivenly coupled to a coil 200 to rotate the coil 200 under the drive of the drive arrangement 130 in order to wind a wire 300 around the coil 200; and (ii) a second position relative to the main body 110 in which the discharge coupling arrangement 120 is drivenly disconnected from the coil 200. Embodiment 2: The material feed mechanism 100 according to embodiment 1, further comprising: a discharge friction wheel (150) rotatably connected to the main body (110), the discharge friction wheel (150) having a wheel surface for frictional connection with a flange (210) of the spool (200), the discharge coupling assembly (120) and the discharge friction wheel (150) being arranged such that, when the discharge coupling assembly (120) is in the first position, the discharge coupling assembly (120) is driven by the discharge friction wheel (150) to rotate the spool (200) through the discharge friction wheel (150), and when the discharge coupling assembly (120) is in the second position, the discharge coupling assembly (120) is driven by the discharge friction wheel (150) separated to drive the discharge coupling arrangement (120) away from the coil (200). Embodiment 3: The material feeding mechanism 100 according to embodiment 2, which further comprises: a loading coupling arrangement (140) connected to the main body (110), wherein the drive arrangement (130) is further configured to drive the loading coupling arrangement (140) so that it is switchable between (i) a third position relative to the main body (110) in which the loading coupling arrangement (140) is drive-disconnected from the wire (300); and (ii) a fourth position relative to the main body (110) in which the loading coupling arrangement (140) is drive-coupled to the wire (300) in order to pull the wire (300) by driving the drive arrangement (130) so that it is released from the spool (200). Embodiment 4: The material feeding mechanism 100 according to embodiment 3, which further comprises: a loading friction wheel (160) rotatably connected to the main body (110), wherein the loading friction wheel (160) has a wheel surface for frictional connection with the wire (300), wherein the loading coupling assembly (140) and the loading friction wheel (160) are arranged such that, when the loading coupling assembly (140) is in the third position, the loading coupling assembly (140) is drivenly disengaged from the loading friction wheel (160) in order to drive the loading coupling assembly (140) away from the wire (300), and when the loading coupling assembly (140) is in the fourth position, the loading coupling assembly (140) is drivenly connected to the loading friction wheel (160) in order to drive the wire (300) to be pulled through the loading friction wheel (160). Embodiment 5: The material feed mechanism 100 according to embodiment 4, wherein the unloading coupling arrangement (120) and the loading coupling arrangement (140) are arranged such that when the unloading coupling arrangement (120) is in the first position, the loading coupling arrangement (140) is in the third position, and when the unloading coupling arrangement (120) is in the second position, the loading coupling arrangement (140) is in the fourth position. Embodiment 6: The material feeding mechanism 100 according to embodiment 5, wherein the drive arrangement 130 comprises a drive motor 131 connected to the main body 110 and a transmission shaft 132 coupled to an output shaft of the drive motor 131, wherein the unloading coupling arrangement 120 and the loading coupling arrangement 140 are mounted on the transmission shaft 132 in such a way that the unloading coupling arrangement 120 and the loading coupling arrangement 140 are pivotable in the circumferential direction when the transmission shaft 132 is rotated around the transmission shaft 132.and wherein the unloading coupling arrangement 120 and the loading coupling arrangement 140 are at an angle to each other in the circumferential direction of the transmission shaft 132, such that when the unloading coupling arrangement 120 is pivoted circumferentially about the transmission shaft 132 in a first direction to the first position, the loading coupling arrangement 140 is pivoted in the first direction to the third position, and when the unloading coupling arrangement 120 is pivoted circumferentially about the transmission shaft 132 in a second direction opposite to the first direction to the second position, the loading coupling arrangement 140 is pivoted in the second direction to the fourth position.and preferably, wherein the unloading coupling arrangement 120 and the loading coupling arrangement 140 are each arranged at two ends of the transmission shaft 132, and preferably, wherein the output shaft of the drive motor 131 is drivenly coupled to a section of the transmission shaft 132 between the unloading coupling arrangement 120 and the loading coupling arrangement 140. Embodiment 7: The material feed mechanism 100 according to embodiment 6, wherein the unloading coupling arrangement 120 and the loading coupling arrangement 140 each comprise: a first connecting element 121 with a first end 1212 which is mounted on the transmission shaft 132 and a second end 1213 which is opposite the first end 1212; a first gear 122 which is mounted on the transmission shaft 132 and is positively connected to the transmission shaft 132; a second gear 123 which is rotatably connected to the second end 1213 of the first connecting element 121 and meshes with the first gear 122;a second connecting element 124, which is arranged with respect to the first gear 122 and the second gear 123 opposite the first connecting element 121, and wherein the first connecting element 121 bears against the first gear 122, so that the first connecting element 121 and the second gear 123 are pivotable in the circumferential direction with the rotation of the transmission shaft 132 and the first gear 122 about the transmission shaft 132. Embodiment 8: The material feed mechanism 100 according to embodiment 7, which further comprises: a first mating gear 151 which is coaxially connected to the discharge friction gear 150, wherein the first mating gear 151 is configured such that, when the discharge coupling arrangement 120 is in the first position, the first mating gear 151 is engaged with the second gear 123 of the discharge coupling arrangement 120, and when the discharge coupling arrangement 120 is in the second position, the first mating gear 151 is disengaged from the second gear 123 of the discharge coupling arrangement 120. Embodiment 9: The material feed mechanism 100 according to embodiment 7 or 8, further comprising: a second mating gear 161 which is coaxially connected to the loading friction gear 160, wherein the second mating gear 161 is configured such that when the loading coupling assembly 140 is in the third position, the second mating gear 161 is disengaged from the second gear 123 of the loading coupling assembly 140, and when the loading coupling assembly 140 is in the fourth position, the second mating gear 161 is engaged with the second gear 123 of the loading coupling assembly 140. Embodiment 10: The material feed mechanism 100 according to one of embodiments 7 to 9, wherein both the unloading coupling arrangement 120 and the loading coupling arrangement 140 further comprise an elastic clamping element 125 for bridging the first connecting element 121 and the second connecting element 124 in order to provide an elastic force that enables the first connecting element 121 and the second connecting element 124 to clamp the first gear 122, preferably, wherein the elastic clamping element 125 comprises: an elastic clamping element body 1251 extending axially parallel to the transmission shaft 132;and two clamping jaws, each connected to two ends of the elastic clamping element body 1251, wherein a first clamping jaw 1252 of the two clamping jaws bears against an outer surface of the first connecting element 121, which points away from the first gear 122 and the second gear 123, and a second clamping jaw 1253 of the two clamping jaws bears against an outer surface of the second connecting element 124, which points away from the first gear 122 and the second gear 123, preferably wherein the outer surface of the first connecting element 121 is provided with a first groove 1211, preferably wherein the outer surface of the second connecting element 124 is provided with a second groove 1241, preferably wherein the first clamping jaw 1252 is provided with a first projection 1252a which engages in the first groove 1211, and preferably wherein the second clamping jaw 1253 is provided with a second projection 1253a is provided, which engages in the second groove 1241.; Embodiment 11: The material feed mechanism 100 according to one of embodiments 3 to 10, wherein the main body 110 is provided with: a first position limiter 111, which is positioned on a movement path of the discharge coupling arrangement 120 relative to the main body 110 such that the discharge coupling arrangement 120 is in the first position when it is moved to bump against the first position limiter 111;and a second position limiter 112, which is positioned on the path of movement of the unloading coupling arrangement 120 relative to the main body 110 such that the unloading coupling arrangement 120 is in the second position when it is moved against the second position limiter 112, preferably wherein the main body 110 is further provided with: a third position limiter 113, which is positioned on a path of movement of the loading coupling arrangement 140 relative to the main body 110 such that the loading coupling arrangement 140 is in the third position when it is moved to abut the third position limiter 113; and a fourth position limiter 114, which is positioned on the path of movement of the loading coupling arrangement 140 relative to the main body 110 such that the loading coupling arrangement 140 is in the fourth position when it is moved against the fourth position limiter 114. Embodiment 12: A multi-material unit comprising: at least one coil 200 around which at least one wire 300 for a 3D printer is wound; and at least one material feed mechanism 100, wherein each material feed mechanism 100 comprises the material feed mechanism 100 according to one of embodiments 1 to 11, wherein the at least one material feed mechanism 100 is for use with the respective at least one coil 200 to feed the at least one wire 300 to the 3D printer. Embodiment 13: A 3D printing system comprising: a 3D printer; at least one spool 200 around which at least one wire 300 for the 3D printer is wound; and at least one material feed mechanism 100, each material feed mechanism 100 comprising: a main body 110; an unloading coupling arrangement 120 connected to the main body 110; and a drive arrangement 130 configured to drive the discharge coupling arrangement 120 in such a way that it is switchable between a first position relative to the main body 110, in which the discharge coupling arrangement 120 is drivenly coupled to a corresponding coil 200 of the at least one coil 200 in order to rotate the corresponding coil 200 under the drive of the drive arrangement 130 in order to wind a corresponding wire 300 of the at least one wire 300 around the corresponding coil 200;and ii a second position relative to the main body 110, in which the discharge coupling arrangement 120 is drive-disconnected from the corresponding coil 200, and wherein the at least one material feed mechanism 100 is for use with the corresponding coil 200 of the at least one coil 200 to feed the at least one wire 300 to the 3D printer. Embodiment 14: The 3D printing system according to embodiment 13, wherein each material feed mechanism 100 further comprises: a loading coupling arrangement 140 connected to the main body 110, wherein the drive arrangement 130 is further configured to drive the loading coupling arrangement 140 so that it is switchable between i a third position relative to the main body 110, in which the loading coupling arrangement 140 is drive-disconnected from the corresponding wire 300; and ii a fourth position relative to the main body 110, in which the loading coupling arrangement 140 is drive-coupled to the corresponding wire 300 in order to pull the corresponding wire 300 from the corresponding spool 200 by driving the drive arrangement 130. Embodiment 15: The 3D printing system according to embodiment 14, wherein for each material feed mechanism 100 the drive arrangement 130 is further configured such that: when the material feed mechanism 100 is actuated for unloading, it drives the unloading coupling arrangement 120 to move into the first position and drives the loading coupling arrangement 140 to move into the third position; when the material feed mechanism 100 is actuated for loading, it drives the unloading coupling arrangement 120 to move into the second position and drives the loading coupling arrangement 140 to move into the fourth position; and when the material feed mechanism 100 was operated for loading to allow the 3D printer to print, the unload coupling assembly 120 was held in the second position and the loading coupling assembly 140 in the fourth position, and the drive assembly 130 was switched off.

[0113] Although the present disclosure has been illustrated and described in detail in the drawings and the preceding description, these illustrations and descriptions should be regarded as illustrative and schematic, and not as limiting; and the present disclosure is not limited to the disclosed embodiments. By studying the drawings, the disclosure, and the accompanying claims, those skilled in the art in this field will be able to understand and implement modifications of the disclosed embodiments when practicing the claimed subject matter. In the claims, the word "comprising" does not exclude other elements or steps not listed, the indefinite article "a" or "an" does not exclude the plural, and the term "a plurality of" means two or more.The mere fact that certain measures are listed in differing dependent claims does not mean that a combination of these measures cannot be used to obtain an advantage. List of reference numbers: 100 Material feeding mechanism; 110 main body; 111 First position limiter; 113 Third position limiter; 112 Second position limiter; 114 Fourth position limiter; 115 wire support frames; 117 Second wall surface; 116 First wall surface; 120 Unloading coupling arrangement; 121 First connecting element; 1211 First groove; 1212 First End; 1213 Second Ending; 122 First gear; 123 Second gear; 124 Second connecting element; 1241 Second groove; 125 Elastic clamping element; 1251 Body of the elastic clamping element; 1252 First clamping jaw; 1253 Second clamping jaw; 1252a First lead; 1253a Second lead; 130 Drive arrangement; 132 Transmission wave; 131 Drive motor; 133 Catching device; 134 worm gear; 135 snail; 140 Loading coupling arrangement; 150 discharge friction wheel; 151 First counter gear; 160 loading friction wheel; 161 Second counter gear; 200 coil; 210 flange; 300 wire; 400 spool holders.

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