Additive printing tool head and additive printer

Abstract

An additive printing tool head, comprising a mounting body, a first nozzle (51), a second nozzle (52), and a filament channel, wherein the mounting body is provided with an extrusion mechanism (3) and a switching mechanism (4); the switching mechanism (4) is movably connected to the mounting body; the filament channel comprises a first filament channel and a second filament channel; and the switching mechanism (4) and the extrusion mechanism (3) work in conjunction such that a first filament in the first filament channel is intermittently clamped or released, or the switching mechanism (4) and the extrusion mechanism (3) work in conjunction such that a second filament in the second filament channel is intermittently clamped or released. The additive printing tool head further comprises a filament limiting mechanism (410) mounted on the mounting body or the switching mechanism. When a target filament in a target filament channel is in at least one position in a non-working state, the filament limiting mechanism (410) abuts against the target filament in the target filament channel so as to limit upward movement of the target filament, wherein the non-working state is a state in which the target filament is partially or fully released by the switching mechanism and the extrusion mechanism.

Description

Additive printing toolheads and additive printers

[0001] Priority information

[0002] This application claims priority to PCT patent application 2025 / 072614, filed on January 15, 2025, and patent application 202510343930.5, filed with the China National Intellectual Property Administration on March 22, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of printing technology, and in particular to an additive printing tool head and an additive printer. Background Technology

[0004] With the rapid development and widespread application of additive printers, dual-head printing assemblies are common printing components. For example, US2024 / 0009927A1 and CN115091750B both provide a dual-head printing assembly. Driven by a drive mechanism and in conjunction with a transmission structure, the first printhead can move up and down relative to the second printhead. Thus, when the working printhead is in use, the idle printhead will not interfere with or collide with the printed model. At the same time, the extrusion mechanism is driven to switch the extrusion position of the filament to correspond with the first or second printhead.

[0005] However, the current solution has technical problems such as unstable printing and easy failure when switching printheads, especially when the additive printer prints materials with high elasticity such as TPU, experiments have shown that the failure rate is high. Summary of the Invention

[0006] This application provides an additive printing tool head and an additive printer.

[0007] The additive printing tool head may include a mounting body, a first nozzle, a second nozzle, and a filament channel. The mounting body is provided with an extrusion mechanism and a switching mechanism, and the switching mechanism is movably connected to the mounting body.

[0008] The wire channel includes a first wire channel and a second wire channel. The switching mechanism 413 and the extrusion mechanism 303 cooperate to intermittently clamp or release the first wire in the first wire channel, or the switching mechanism 423 and the extrusion mechanism 303 cooperate to intermittently clamp or release the second wire in the second wire channel. The first nozzle is used to receive the first wire conveyed downward through the first wire channel, and the second nozzle is used to receive the second wire conveyed downward through the second wire channel.

[0009] It also includes a wire limiting mechanism 410 installed on the installation body or switching mechanism. When the target wire in the target wire channel is in at least one position in the non-working state, the wire limiting mechanism 410 abuts against the target wire in the target wire channel to restrict the target wire from moving upward. The non-working state is the state in which the target wire is partially or completely released by the switching mechanism and the extrusion mechanism.

[0010] The target wire channel is either the first wire channel or the second wire channel. When the target wire channel is the first wire channel, the target wire is the first wire; when the target wire channel is the second wire channel, the target wire is the second wire.

[0011] Thus, by setting the wire limiting mechanism 410 to abut against the target wire, the movement of the target wire relative to the mounting body or the switching mechanism can still be restricted after the target wire is released by the extrusion mechanism 303 and the switching mechanism 413. This avoids the target wire being pulled back into the throat and causing a blockage when the tool head uses another wire for printing.

[0012] In some embodiments, the extrusion mechanism includes an extrusion motor and an extrusion wheel. The extrusion motor is connected to the extrusion wheel and drives the extrusion wheel to rotate. The switching mechanism includes a first swing mechanism having a first wire channel and a second swing mechanism having a second wire channel. The first swing mechanism and the second swing mechanism are rotatably mounted on the mounting body.

[0013] In some embodiments, the movement of the switching mechanism relative to the mounting body is driven by an active drive element, which includes a drive motor. The drive motor is connected to the switching mechanism via a transmission element or directly. Under the control of the drive motor, the switching mechanism switches between a working state and a non-tooling state. In some embodiments, the movement of the switching mechanism relative to the mounting body can be passively triggered. Both the switching mechanism and the mounting body are mounted on the tool head. By controlling the movement of the tool head, the tool head can be made to abut against other structures other than the tool head at certain positions, thereby enabling the switching mechanism to switch between a working state and a non-tooling state.

[0014] When the target swing mechanism swings relative to the mounting body and cooperates with the extrusion wheel in the working state, the target wire in the target wire channel is clamped to convey or retract the target wire, and the wire limiting mechanism 410 releases the target wire.

[0015] When the target wire channel is the first wire channel, the target swing mechanism is the first swing mechanism; when the target wire channel is the second wire channel, the target swing mechanism is the second swing mechanism.

[0016] The wire limiting mechanism 410 includes a cutting edge, tip, protrusion structure, or downwardly extending tooth-like, hook-like, or claw-like structure that abuts the wire. The wire limiting mechanism 410 moves relative to the wire to abut or release the wire.

[0017] Furthermore, the wire limiting mechanism 410 includes a first wire limiting mechanism 410 disposed on and movably connected to the first swing mechanism, and a second wire limiting mechanism 410 disposed on and movably connected to the second swing mechanism.

[0018] The target swing mechanism swings to at least one non-working position, so that the target wire limiting mechanism 410 cooperates with the installation body to drive the target wire limiting mechanism 410 to abut against the target wire in the target wire channel and restrict the target wire from moving upward.

[0019] When the target wire channel is the first wire channel, the target wire limiting mechanism 410 is the first wire limiting mechanism 410; when the target wire channel is the second wire channel, the target wire limiting mechanism 410 is the second wire limiting mechanism 410.

[0020] In some embodiments, the wire limiting mechanism 410 is installed on the installation body and movably connected to the installation body, and the wire limiting mechanism 410 includes a first wire limiting mechanism 410 and / or a second wire limiting mechanism 410;

[0021] The first swing mechanism swings to at least one non-working position, causing the first wire limiting mechanism 410 to cooperate with the first swing mechanism, including: the first wire limiting mechanism 410 moving relative to the mounting body to abut against the first wire in the first wire channel and restrict the upward movement of the first wire, and / or,

[0022] The second swing mechanism swings to at least one non-working position, causing the second wire limiting mechanism 410 to cooperate with the second swing mechanism, including: the second wire limiting mechanism 410 moving relative to the mounting body to abut against the second wire in the second wire channel and restrict the upward movement of the second wire.

[0023] It is understood that the wire limiting mechanism 410 can be set on the switching mechanism, such as the first swing mechanism or the second swing mechanism, or it can be set on the installation body. As the switching mechanism moves relative to the installation body, the wire limiting mechanism 410 is in different trigger states at different positions through the interaction of the cooperative structure, thereby allowing the wire limiting mechanism 410 to switch between the state of contacting the target wire and releasing the target wire.

[0024] Specifically, the second swing mechanism engages with the extrusion wheel through swinging to clamp the second wire in the second wire channel, thus putting it into a working state. When the wire limiting mechanism 410 releases the first wire, the first swing mechanism swings to at least one non-working position, causing the first wire limiting mechanism 410 and the first swing mechanism to cooperate with each other. This includes: the first wire limiting mechanism 410 moving relative to the mounting body to abut against the first wire in the first wire channel and restrict the upward movement of the first wire; and / or...

[0025] The first swing mechanism engages with the extrusion wheel to clamp the first wire in the first wire channel, thus putting it into a working state. When the wire limiting mechanism 410 releases the first wire, the second swing mechanism swings to at least one position in the non-working state, so that the second wire limiting mechanism 410 and the second swing mechanism cooperate with each other, including: the second wire limiting mechanism 410 moves relative to the mounting body to abut against the second wire in the second wire channel and restrict the upward movement of the second wire.

[0026] In some embodiments, the switching mechanism includes a first swing mechanism having a first wire channel and a second swing mechanism having a second wire channel, the first swing mechanism rotating about a first rotating shaft 414 and the second swing mechanism rotating about a second rotating shaft 424;

[0027] The distance between the first wire limiting mechanism 410 and the first rotating shaft 414 is L1. In the working state, the distance between the clamping point of the extrusion wheel and the first wire and the first rotating shaft 414 is J1. L1 > J1, ensuring that before the first swing mechanism rotates to completely release the first wire, the first wire limiting mechanism 410 abuts against the first wire, and / or...

[0028] The distance between the second wire limiting mechanism 410 and the second rotating shaft 424 is L2. In the working state, the distance between the clamping point of the extrusion wheel and the second wire and the second rotating shaft 424 is J2. L2 > J2, so that before the second swing mechanism rotates to completely release the second wire, the second wire limiting mechanism 410 abuts against the second wire.

[0029] Understandably, by setting the wire limiting mechanism 410 at a position farther from the clamping point relative to the rotating shaft than the clamping point, the wire limiting mechanism releases the target wire during operation. Furthermore, after the switcher begins to swing or rotate, the movement distance of the wire limiting mechanism 410 is greater than the movement distance of the clamping point. This allows the wire limiting mechanism to engage the target wire before it is completely released, thus minimizing the time the target wire is in a released state from the start of the switching mechanism's release until the wire limiting mechanism engages with the wire. When the target wire is an elastic wire, this ensures the wire remains clamped, reducing the probability of clogging.

[0030] In some embodiments, the filament limiting mechanism 410 mounted on the tool head switches between positions of abutting and releasing the target filament by engaging with other structures other than the tool head. For example, the additive printing tool head is mounted on the 3D printer frame via a trolley and can move in at least one plane. The additive printing tool head engages with the trolley or frame to trigger the filament limiting mechanism 410 to move relative to the mounting body to abut or release the filament.

[0031] Furthermore, the wire limiting mechanism 410 is a spring-type latching mechanism or a push-push mechanism structure. When the wire limiting mechanism 410 and the trolley or frame first cooperate in the trigger position, the locking position is triggered. The locking position causes the wire limiting mechanism 410 to abut against the wire. When the wire limiting mechanism 410 and the trolley or frame cooperate again in the trigger position, the release position is triggered. The release position causes the wire limiting mechanism 410 to release the wire.

[0032] In some embodiments, the wire limiting mechanism 410 cooperates with the trolley or frame at a trigger position to push the wire limiting mechanism 410 to slide or rotate relative to the mounting body, thereby causing the wire limiting mechanism 410 to abut or release the wire.

[0033] In some embodiments, the wire limiting mechanism 410 includes a first wire limiting mechanism 410 corresponding to the first wire and a second wire limiting mechanism 410 corresponding to the second wire, and also includes a limiting mechanism connector that is slidably or rotatably connected to the mounting body. The first wire limiting mechanism 410 and the second wire limiting mechanism 410 are fixedly connected by the limiting mechanism connector.

[0034] The limiting mechanism connector drives the first wire limiting mechanism 410 and the second wire limiting mechanism 410 to move synchronously, so that when the first wire limiting mechanism 410 is in the position of abutting the first wire, the second wire limiting mechanism 410 is in the position of releasing the second wire; when the first wire limiting mechanism 410 is in the position of releasing the first wire, the second wire limiting mechanism 410 is in the position of abutting the second wire.

[0035] It is understandable that by setting a limiting mechanism connector to connect the first wire limiting mechanism 410 and the second wire limiting mechanism 410, the wire limiting mechanism 410 can switch positions of the first wire limiting mechanism 410 and the second wire limiting mechanism 410 with only one trigger or one drive. In some embodiments, when the first wire limiting mechanism 410 abuts against the first wire, the second wire limiting mechanism 410 releases the second wire, and when the first wire limiting mechanism 410 releases the first wire, the second wire limiting mechanism 410 abuts against the second wire.

[0036] In some embodiments, the wire limiting mechanism 410 is installed on the installation body and movably connected to the installation body, or the wire limiting mechanism 410 is installed on the switching mechanism and movably connected to the switching mechanism;

[0037] The wire limiting mechanism 410 includes a wire limiting drive motor and a wire limiting component. The limiting drive motor and the wire limiting component are directly connected in transmission. Alternatively, the wire limiting mechanism 410 includes a wire limiting drive motor and a transmission component. The wire limiting drive motor, the transmission component, and the wire limiting component are sequentially connected in transmission.

[0038] The wire limiting component moves relative to the wire under the drive of the limiting drive motor to abut or release the wire.

[0039] In some embodiments, the wire limiting mechanism 410 is installed on the installation body and movably connected to the installation body, or the wire limiting mechanism 410 is installed on the switching mechanism and movably connected to the switching mechanism;

[0040] The wire limiting mechanism 410 includes an electromagnetic coil, a magnetic conductor, and a wire limiting component. One of the electromagnetic coil or the magnetic conductor is disposed on the wire limiting component, and the other of the electromagnetic coil or the magnetic conductor is disposed on the mounting body or the switching mechanism. The magnetic conductor is a soft magnetic material or a magnet. The wire limiting component moves relative to the mounting body or the switching mechanism under the drive of the electromagnetic coil to abut or release the wire.

[0041] It is understandable that the wire limiting mechanism 410 can also be set as an active component. In this case, the state of the wire limiting mechanism 410 can be flexibly controlled according to the requirements, without relying on the movement of the switching mechanism relative to the installation body or the contact and cooperation between the tool head and other structures other than the tool head.

[0042] Furthermore, the wire limiting mechanism 410 includes an elastic element or a magnetic element and a wire limiting element, wherein the wire limiting element is connected to the elastic element or the magnetic element in a transmission connection or a fixed connection.

[0043] In some embodiments, the wire limiting mechanism 410 is disposed on the target swing mechanism. When the target wire in the target wire channel is clamped and thus in a working state, the elastic member is in either a compressed state or a restored state, so that the wire limiting member is released from the target wire. When the target wire channel is in at least one non-working state, the elastic member is in either a compressed state or a restored state, so that the wire limiting member abuts against the target wire to restrict the upward movement of the target wire in the target wire channel. Alternatively, when the target wire in the target wire channel is clamped and thus in a working state, the magnetic member is in either a released state or an attracted state, so that the wire limiting member is released from the target wire. When the target wire channel is in at least one non-working state, the magnetic member is in either a released state or an attracted state, so that the wire limiting member abuts against the target wire to restrict the upward movement of the target wire in the target wire channel.

[0044] In other embodiments, the wire limiting mechanism 410 is disposed on the mounting body. When the target wire in the target wire channel is clamped and thus in a working state, the elastic member is in either a compressed state or a restored state, so that the wire limiting member is released from the target wire. When the target wire channel is in at least one non-working state, the elastic member is in either a compressed state or a restored state, so that the wire limiting member abuts against the target wire to restrict the upward movement of the target wire in the target wire channel. Alternatively, when the target wire in the target wire channel is clamped and thus in a working state, the magnetic member is in either a released state or an attracted state, so that the wire limiting member is released from the target wire. When the target wire channel is in at least one non-working state, the magnetic member is in either a released state or an attracted state, so that the wire limiting member abuts against the target wire to restrict the upward movement of the target wire in the target wire channel.

[0045] When the target wire channel is the first wire channel, the target wire is the first wire, and the target swing mechanism is the first swing mechanism; when the target wire channel is the second wire channel, the target wire is the second wire, and the target swing mechanism is the second swing mechanism.

[0046] In some embodiments, the wire limiting mechanism 410 includes an elastic element and a wire limiting element, wherein the wire limiting element and the elastic element are connected in a transmission manner or in a fixed manner.

[0047] The wire limiting mechanism 410 is provided on the target swing mechanism or the mounting body. One end of the elastic element abuts against the target swing mechanism or the mounting body, and the other end of the elastic element is connected to the wire limiting element. When the target wire in the target wire channel is clamped and thus in a working state, the elastic element or the wire limiting element is abutted by the target swing mechanism or the mounting body, so that the elastic element is in either a compressed state or a restored state, so that the wire limiting element is released from the target wire.

[0048] When the target wire channel is in at least one non-working position, the elastic element or wire limiting element disengages from the target swing mechanism or mounting body, so that the elastic element is in either a compressed state or a restored state, and the wire limiting element abuts against the target wire to restrict the upward movement of the target wire within the target wire channel.

[0049] In some embodiments, the wire limiting mechanism 410 includes a magnetic element and a wire limiting element, wherein the wire limiting element and the magnetic element are connected in a transmission manner or in a fixed manner.

[0050] The wire limiting mechanism 410 is set on the target swing mechanism or the mounting body. When the target wire in the target wire channel is clamped and thus in working state, the magnetic component is in one of the repulsive, natural, or adsorption states, or the wire limiting component is abutted by the target swing mechanism or the mounting body, so that the wire limiting component is released from the target wire.

[0051] When the target wire channel is in at least one non-working position, the magnetic component is in a repulsive or natural state and an adsorption state, or the wire limiting component is disengaged from the target swing mechanism or the mounting body, so that the wire limiting component abuts against the target wire to restrict the upward movement of the target wire in the target wire channel.

[0052] This application provides an additive printer, which includes the additive printing tool head described above.

[0053] The additive printing tool head and additive printer provided in this application embodiment can make the filament limiting mechanism abut against the current filament of the target printhead to limit the retraction of the current filament, and control the switching mechanism to cooperate with the extrusion mechanism to make the extrusion mechanism release the clamping of the current filament, and before the switching mechanism and the extrusion mechanism clamp the filament again for printing, the filament limiting mechanism releases the abutment of the current filament. Thus, from the time the current filament of the target printhead is released to the time the target printhead and the extrusion mechanism are controlled to clamp the filament again for printing, the movement of the current filament is restricted by the filament limiting mechanism, thereby avoiding the current filament retracting into the throat and causing a blockage.

[0054] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0055] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0056] Figure 1 is a schematic diagram of the motor layout of an additive printing tool head according to an embodiment of this application;

[0057] Figure 2 is a front view of an additive printing tool head according to an embodiment of this application;

[0058] Figure 3 is a schematic diagram of the first fan of an additive printing tool head according to an embodiment of this application;

[0059] Figure 4 is a schematic diagram of the second cooling mechanism of an additive printing tool head according to an embodiment of this application;

[0060] Figure 5 is a side view of an additive printing tool head according to an embodiment of this application;

[0061] Figure 6 is a schematic diagram of the overall layout of an additive printing tool head according to an embodiment of this application;

[0062] Figure 7 is an exploded view of the overall structure of an additive printing tool head according to an embodiment of this application;

[0063] Figure 8 is a schematic diagram of an extrusion and switching mechanism for an additive printing tool head according to an embodiment of this application;

[0064] Figure 9 is a front view of an extrusion and switching mechanism of an additive printing tool head according to an embodiment of this application;

[0065] Figures 10a, 10b, and 10c are schematic diagrams of the operation of a switching mechanism for an additive printing tool head according to an embodiment of this application;

[0066] Figure 11 is an exploded view of the extrusion mechanism, switching mechanism, and cutting mechanism of an additive printing tool head according to an embodiment of this application;

[0067] Figure 12 is a front view of an extrusion, switching and cutting mechanism of an additive printing tool head according to an embodiment of this application;

[0068] Figure 13 is a schematic diagram of the first cutting mechanism of an additive printing tool head in the working position according to an embodiment of this application;

[0069] Figure 14 is a schematic diagram of the first cutting mechanism of an additive printing tool head according to an embodiment of this application;

[0070] Figure 15 is a schematic diagram of the first cutting mechanism of an additive printing tool head in a non-working position according to an embodiment of this application;

[0071] Figure 16 is a schematic diagram of the inner structure of the first cover and the material guide cover of an additive printing tool head according to an embodiment of this application;

[0072] Figure 17 is a top view of a limiting member and wire limiting mechanism for an additive printing tool head according to an embodiment of this application;

[0073] Figure 18 is a schematic diagram of a limiting member and a wire limiting mechanism for an additive printing tool head according to an embodiment of this application;

[0074] Figure 19 is a partial schematic diagram of the first limiting member and the first wire limiting mechanism of an additive printing tool head according to an embodiment of this application;

[0075] Figure 20 is a partial schematic diagram of the second limiting member of an additive printing tool head according to an embodiment of this application;

[0076] Figure 21 is a partial schematic diagram of the first limiting member of an additive printing tool head according to an embodiment of this application;

[0077] Figure 22 is a partial schematic diagram of a wire limiting mechanism for an additive printing tool head according to an embodiment of this application;

[0078] Figure 23 is a flowchart illustrating the control method of the additive printing tool head in some embodiments of this application;

[0079] Figure 24 is a schematic diagram of application scenarios in some embodiments of this application;

[0080] Figure 25 is a schematic diagram of application scenarios in some embodiments of this application;

[0081] Figure 26 is a schematic diagram of application scenarios in some embodiments of this application;

[0082] Figure 27 is a schematic diagram of application scenarios in some embodiments of this application;

[0083] Figure 28 is a schematic diagram of application scenarios in some embodiments of this application;

[0084] Figure 29 is a schematic diagram of application scenarios in some embodiments of this application;

[0085] Figure 30 is a schematic diagram of a wire limiting mechanism in some embodiments of this application;

[0086] Figure 31 is a schematic diagram of application scenarios in some embodiments of this application;

[0087] Figure 32 is a schematic diagram of application scenarios in some embodiments of this application. Detailed Implementation

[0088] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of this application, and should not be construed as limiting the embodiments of this application.

[0089] This application provides an additive printing tool head. The layout of the tool head components and the related structure and working principle of the extrusion mechanism are as follows:

[0090] As shown in Figures 1-7, the additive printing tool head of this embodiment includes a mounting body, a first printhead 51, a second printhead 52, and a filament channel. The mounting body is equipped with an extrusion mechanism 3, a guide rail mounting part 101, a lifting mechanism 5, the first printhead 51, and the second printhead 52. The extrusion mechanism 3 includes an extrusion motor 301, and the lifting mechanism 5 includes a lifting motor 501. The extrusion motor 301 is mounted on the first side of the mounting body and located above the guide rail mounting part 101, while the lifting motor 501 is mounted on the first side of the mounting body and located below the guide rail mounting part 101. The device also includes a switching mechanism 4, which includes a switching motor 401, arranged side-by-side on one side of the extrusion motor 301. The separately configured extrusion motor, lifting motor, and switching motor execute actions according to control commands, effectively preventing interference between printhead lifting, filament extrusion, and switching operations. This prevents unwanted filament overflow from printheads that have finished printing, and decouples the lifting, filament extrusion, and switching operations, allowing for independent control and monitoring of different processes. This improves the automation level of the equipment and enables more functions. The extrusion motor is located above the guide rail mounting section, while the lifting motor is below. This ensures the lifting motor is closer to the printhead, shortening the transmission chain, improving transmission accuracy, reducing the size of transmission components, and balancing the tool head's center of gravity, minimizing "nodding" deformation when moving along the guide rail.

[0091] The mounting body includes a first mounting part 1 and a second mounting part 2. The first mounting part 1 is at least partially fixed to the upper part of the second mounting part 2. The extrusion mechanism 3 and the switching mechanism 4 are disposed on the first mounting part 1, and the lifting mechanism 5, the first nozzle 51, and the second nozzle 52 are disposed on the second mounting part 2. The guide rail mounting part 101 is disposed on either the first mounting part 1 or the second mounting part 2. The mounting body can be manufactured as a single piece or constructed by connecting multiple parts. It is used to support the various components of the tool head. For example, a high-strength metal mounting body can be formed by integral die casting, and the installation positions of each component can be precisely machined through subtractive manufacturing. This can achieve a shorter relative positional dimension chain of each component, thereby improving the installation accuracy.

[0092] The switching mechanism 4 also includes a switching motor reduction mechanism 402. The switching motor 401 and the switching motor reduction mechanism 402 are stacked, with their stacked axial height being flush with or similar to the axial height of the extrusion motor 301. The power and size of the extrusion motor 301 are greater than those of the switching motor 401. The switching motor reduction mechanism 402 is a planetary reduction transmission mechanism, such as a double planetary reducer. The extrusion motor 301 is a permanent magnet synchronous motor. In this layout, the extrusion motor can use a relatively large size and operating power, enabling high-speed filament extrusion, thereby improving printing speed and efficiency. The switching motor is smaller, and the use of a planetary reducer ensures that the stacked axial height of the switching motor 401 and the switching motor reduction mechanism 402 is flush with or similar to the height of the extrusion motor, thus preventing the print head size from undesirably increasing due to the increased number of motors.

[0093] One or more linear guides are installed in the guide rail mounting part 101 and are located in the middle area of ​​the extrusion motor 301, the switching motor 401, the lifting motor 501, the first fan 601 and the second fan 701. The tool head is mounted on the linear rail via a guide rail mounting part and can move in the X direction, while the linear rail can move in the Y direction. The switching mechanism 4 also includes a switching motor reduction mechanism 402, and the lifting mechanism 5 also includes a lifting motor reduction mechanism 507. The centroid of the tool head's projection in the XY plane or the projection of the tool head's center of gravity in the XY plane coincides with the projection of the linear rail, and / or, at least one of the extrusion motor 301 and the switching motor 401 or the switching motor reduction mechanism 402, and at least one of the lifting motor 501 or the lifting motor reduction mechanism, all have projections in the XY plane that at least partially overlap with the projection of the linear rail. It is understood that the extrusion motor 301 and the switching motor 401 or the switching motor reduction mechanism 402 have high mass, which has a significant impact on the centroid distribution of the tool head. By distributing the motors up and down around the linear rail, the centroid of the tool head is closer to the linear rail in the height direction, thereby reducing the acceleration and deceleration torque of the tool head in the Y-axis direction, reducing the nozzle deformation introduced during the processing motion, and thus improving the printing quality.

[0094] When there are two or more linear guides, the centroid of the tool head's projection in the XY plane, or the center of gravity of the tool head, is located in the area between at least the two outermost linear guides. The tool head also includes a control plate. The tool head is connected to the additive manufacturing equipment via a cable chain, one end of which is mounted to the tool head via a cable chain connector. At least a portion of the projections of the first nozzle 51, the second nozzle 52, and the wire channel in the XY plane are located on the first side of the linear guide's projection in the XY plane. At least a portion of the cooling mechanism, the control plate, and at least one of the cable chain or cable chain connector have projections in the XY plane located on the second side of the linear guide's projection in the XY plane, opposite to the first side. This arrangement ensures that the components surround the linear guides, guaranteeing a stable center of gravity, stable operation, and high overall strength of the tool head. In this application, the linear guide can be fixedly installed on the support profile, which can move together with the linear guide along the Y direction. When referring to the projection of the linear guide, it can refer to the projection of the whole formed by the support profile and the linear guide, or more precisely, the projection of the linear guide on the support profile.

[0095] The extrusion mechanism 3 further includes an extrusion motor reduction mechanism 302 and an extrusion wheel 303. The extrusion motor reduction mechanism 302 includes a first reduction gear 304, which is centrally located on the second side of the mounting body, the second side being the side opposite to the first side. The extrusion wheel 303 and the output shaft of the extrusion motor employ a single-stage reduction transmission, and the extrusion wheel 303 and the first reduction gear 304 are coaxially arranged. The diameter of the extrusion wheel can be set to be consistent with the position of the wire channel, so that the wire is transported as straight as possible. The extrusion motor is distributed on both sides of the centerline of the mounting body through transmission gears, which can make full use of the tool head mounting space, allowing for a larger size of the extrusion motor reduction gear, thereby achieving greater driving force and single-stage reduction. The single-stage reduction transmission between the extrusion motor reduction gear and the extrusion motor effectively reduces the number of gear transmission stages, improves transmission accuracy, facilitates closed-loop control, and thus has greater power and extrusion speed, achieving high-speed printing.

[0096] The second nozzle 52 is fixedly disposed on the second side of the second mounting part 2 and is disposed adjacent to the first nozzle 51.

[0097] The relevant structure and working principle of the switching mechanism are as follows:

[0098] As shown in Figures 8-11, the switching mechanism 4 includes a switching motor 401, a switching motor reduction mechanism 402, a first transmission gear 403, a second transmission gear 404, a switching cam 405, a first swing mechanism 406, a second swing mechanism 407, and an elastic element 408. The switching motor reduction mechanism 402 is connected to the first transmission gear 403. The first swing mechanism 406, the second swing mechanism 407, and the elastic element 408 are all located on the second side of the mounting body. The first transmission gear 403 is meshed with the second transmission gear 404, and the second transmission gear 404 drives the switching cam 405 to swing. The switching cam 405 is centrally located on the mounting body and above the first reduction gear 304. The first swing mechanism 406 and the second swing mechanism 407 are symmetrically arranged on both sides of the switching cam 405. The first swing mechanism 406 includes a first switching part 411, a first pressure roller 413, and a first swing pivot part 414 arranged sequentially from top to bottom; the second swing mechanism 407 includes a second switching part 421, a second pressure roller 423, and a second swing pivot part 424 arranged sequentially from top to bottom; when the switching cam 405 applies a biasing force to the second switching part 421, the second switching part 421 moves away from the cam axis, and the first switching part 411 moves towards the cam axis under the action of the elastic element 408, the second pressure roller 423 moves away from the extrusion roller 303, and the first pressure roller 413 moves towards the extrusion roller 303, cooperating to transport the first wire; when the switching cam 405 applies a biasing force to the first switching part 411, the first switching part 411 moves away from the cam axis, and the second switching part 421 moves towards the cam axis under the action of the elastic element 408, the first pressure roller 413 moves away from the extrusion roller 303, and the second pressure roller 423 moves towards the extrusion roller 303, cooperating to transport the second wire.

[0099] The first swing pivot 414 and the second swing pivot 424 are respectively located near the lower ends of the first swing mechanism 406 and the second swing mechanism 407. The switching cam is located at the upper end, while the swing pivot is located at the lower end. The switching cam is positioned away from the swing pivot, which ensures that the bias force between the switching cam and the switching part is small, thereby reducing the wear of the cam and improving its service life.

[0100] Along the top-to-bottom direction of the first swing mechanism 406, a first hinge portion 412 is provided between the first switching portion 411 and the first pressure roller 413; along the top-to-bottom direction of the second swing mechanism 407, a second hinge portion 422 is provided between the second switching portion 421 and the second pressure roller 423; the first swing mechanism 406 and the second swing mechanism 407 are symmetrically arranged on both sides of the switching cam 405. The two ends of the elastic element 408 are respectively connected to the first hinge portion 412 and the second hinge portion 422; or, the elastic element 408 includes two elastic elements, the first ends of which are both fixed ends, and the second ends are respectively connected to one of the first hinge portion 412 and the second hinge portion 422. The elastic element 408 is a tension spring connected at both ends to the first hinge portion 412 and the second hinge portion 422 respectively. In the intermediate state of the switching action of the switching cam 405, the spring tension is relatively large. When the switching cam 405 drives the first switching portion 411 or the second switching portion 421 to the working position, the spring is in a non-horizontal state and the tension is relatively small. Thus, the first switching portion 411 or the second switching portion 421 can have a bistable position in the working positions on both sides, and an unstable position in the intermediate state, which helps improve the reliability of the switching action. It should be noted that the extrusion wheel is centrally located, and the two switching portions are symmetrically arranged on both sides of the extrusion wheel. More specifically, the extrusion wheel 303 is located between the first swing pivot portion 414, the second swing pivot portion 424, and the elastic element 408, and the switching cam is located above the extrusion wheel, allowing for a reasonable arrangement of the tool head space. The two swing mechanisms are identical in shape and symmetrically arranged. When in the working position on either side, the spring is in a non-horizontal state, and the spring force is less than the spring force when the connection point of the two springs is in a horizontal state. This can form a "bistable" switching, which is beneficial to improving the reliability of the switching action.

[0101] Since the distance between the elastic element 408 and the pivot is greater than the distance between the extrusion wheel 303 and the pivot, the force acting on the extrusion wheel 303 will be greater than the tension of the elastic element. This allows the size of the elastic element to be set smaller, which is beneficial for miniaturization and weight reduction of the tool head.

[0102] It also includes a first cover 11, which provides pivot support for at least one of the first swing pivot 414 and the second swing pivot 424 or the extrusion wheel. The first cover 11 is disposed on the second side of the mounting body. A cam positioning block 409 is provided on the switching cam 405, and a magnetic element 4091 is provided on the cam positioning block 409. A first Hall sensor 4092 and a second Hall sensor 4093 are provided on the first cover or the mounting body (e.g., the first mounting part) to detect the swing angle of the switching cam 405 or to detect the swing position of the first swing mechanism 406 and the second swing mechanism 407. A first positioning boss 111 and a second positioning boss 112 are also provided on the first cover 11 or the mounting body (e.g., the first mounting part) to limit the swing range of the cam positioning block 409. The cam positioning block 409 has a trapezoidal structure. The magnetic element 4091 is a ring magnet. The first Hall sensor 4092 and the second Hall sensor 4093 are arranged on the first cover 11 or the mounting body at a 90° angle to the line connecting the cam shaft, and are in the same plane as the ring magnet. The ring magnet also has a D-shaped hole. The switching cam cooperates with the switching parts of the swing mechanism on the left and right sides. The plane of the trapezoidal positioning block, which is coaxial with the switching cam, contacts the positioning boss on the first cover to form a limit and position. The switching cam and the trapezoidal positioning block can be integrally formed. A magnet can be set on the outside of the trapezoidal positioning block. Hall sensors arranged at right angles are provided on the first cover at the corresponding positions of the magnets to detect the position angle of the switching cam.

[0103] Through extensive experimentation and summarization, the inventors discovered that in intermittently clamped dual-nozzle or multi-nozzle printers, when the printing filament is released by the extrusion mechanism, the filament end typically retracts due to its own elasticity, wobbling, and filament friction as the tool head moves. During printing, along the filament transport direction, there is generally at least an extrusion mechanism, a heat dissipation end, a throat, and a nozzle. The filament is heated in the nozzle to keep it in a molten state. If the extrusion mechanism releases the filament, the molten filament in the nozzle below the extrusion mechanism may retract to the throat (heat break) and cool and solidify, forming a hard lump that blocks the throat channel, leading to clogging and preventing subsequent printing jobs. Understandably, clogging requires operators to stop the machine to clean the throat or replace the heat break, resulting in printing job failures, consuming significant maintenance time, and impacting the lifespan of the additive printer—a serious printing malfunction.

[0104] As shown in Figures 24-32, the additive printing tool head may include a mounting body, a first nozzle, a second nozzle, and a filament channel. The mounting body is provided with an extrusion mechanism and a switching mechanism, and the switching mechanism is movably connected to the mounting body.

[0105] The wire channel includes a first wire channel and a second wire channel. The switching mechanism 413 and the extrusion mechanism 303 cooperate to intermittently clamp or release the first wire in the first wire channel, or the switching mechanism 423 and the extrusion mechanism 303 cooperate to intermittently clamp or release the second wire in the second wire channel. The first nozzle is used to receive the first wire conveyed downward through the first wire channel, and the second nozzle is used to receive the second wire conveyed downward through the second wire channel.

[0106] It also includes a wire limiting mechanism 410 installed on the installation body or switching mechanism. When the target wire in the target wire channel is in at least one position in the non-working state, the wire limiting mechanism 410 abuts against the target wire in the target wire channel to restrict the target wire from moving upward. The non-working state is the state in which the target wire is partially or completely released by the switching mechanism and the extrusion mechanism.

[0107] The target wire channel is either the first wire channel or the second wire channel. When the target wire channel is the first wire channel, the target wire is the first wire; when the target wire channel is the second wire channel, the target wire is the second wire.

[0108] Thus, by setting the wire limiting mechanism 410 to abut against the target wire, the movement of the target wire relative to the mounting body or the switching mechanism can still be restricted after the target wire is released by the extrusion mechanism 303 and the switching mechanism 413. This avoids the target wire being pulled back into the throat and causing a blockage when the tool head uses another wire for printing.

[0109] In some embodiments, the extrusion mechanism includes an extrusion motor and an extrusion wheel. The extrusion motor is connected to the extrusion wheel and drives the extrusion wheel to rotate. The switching mechanism includes a first swing mechanism having a first wire channel and a second swing mechanism having a second wire channel. The first swing mechanism and the second swing mechanism are rotatably mounted on the mounting body.

[0110] The oscillation of the first and second oscillating mechanisms relative to the mounting body includes, as shown in CN115091750A, driving the extrusion wheel or mating wheel to move via a slide block, or as shown in US20240009927A, driving the extrusion wheel or mating wheel to move via a crank or cam. In some embodiments, the movement of the switching mechanism relative to the mounting body is driven by an active drive element, including a drive motor, which is connected to the switching mechanism via a transmission element or directly. Under the control of the drive motor, the switching mechanism switches between a working state and a non-tooling state. In some embodiments, the movement of the switching mechanism relative to the mounting body can be passively triggered. Both the switching mechanism and the mounting body are mounted on a tool head. By controlling the movement of the tool head, the tool head can be made to abut against other structures other than the tool head at certain positions, thereby enabling the switching mechanism to switch between a working state and a non-tooling state.

[0111] When the target swing mechanism swings relative to the mounting body and cooperates with the extrusion wheel in the working state, the target wire in the target wire channel is clamped to convey or retract the target wire, and the wire limiting mechanism 410 releases the target wire.

[0112] When the target wire channel is the first wire channel, the target swing mechanism is the first swing mechanism; when the target wire channel is the second wire channel, the target swing mechanism is the second swing mechanism.

[0113] The wire limiting mechanism 410 includes a cutting edge, tip, protrusion, or downwardly extending toothed, hook-shaped, or claw-shaped structure that abuts against the wire. The wire limiting mechanism 410 moves relative to the wire to abut or release the wire. It is understood that the wire limiting mechanism can include various types; mechanisms that abut against the wire to limit the movement of the wire relative to the mounting body or switching mechanism can all achieve the effect of abutting the wire and limiting its upward movement.

[0114] Furthermore, the wire limiting mechanism 410 includes a first wire limiting mechanism 410 disposed on and movably connected to the first swing mechanism, and a second wire limiting mechanism 410 disposed on and movably connected to the second swing mechanism.

[0115] The target swing mechanism swings to at least one non-working position, so that the target wire limiting mechanism 410 cooperates with the installation body to drive the target wire limiting mechanism 410 to abut against the target wire in the target wire channel and restrict the target wire from moving upward.

[0116] When the target wire channel is the first wire channel, the target wire limiting mechanism 410 is the first wire limiting mechanism 410; when the target wire channel is the second wire channel, the target wire limiting mechanism 410 is the second wire limiting mechanism 410.

[0117] In some embodiments, the wire limiting mechanism 410 is installed on the installation body and movably connected to the installation body, and the wire limiting mechanism 410 includes a first wire limiting mechanism 410 and / or a second wire limiting mechanism 410;

[0118] The first swing mechanism swings to at least one non-working position, causing the first wire limiting mechanism 410 to cooperate with the first swing mechanism, including: the first wire limiting mechanism 410 moving relative to the mounting body to abut against the first wire in the first wire channel and restrict the upward movement of the first wire, and / or,

[0119] The second swing mechanism swings to at least one non-working position, causing the second wire limiting mechanism 410 to cooperate with the second swing mechanism, including: the second wire limiting mechanism 410 moving relative to the mounting body to abut against the second wire in the second wire channel and restrict the upward movement of the second wire.

[0120] It is understood that the wire limiting mechanism 410 can be set on the switching mechanism, such as the first swing mechanism or the second swing mechanism, or it can be set on the installation body. As the switching mechanism moves relative to the installation body, the wire limiting mechanism 410 is in different trigger states at different positions through the interaction of the cooperative structure, thereby allowing the wire limiting mechanism 410 to switch between the state of contacting the target wire and releasing the target wire.

[0121] Specifically, the second swing mechanism engages with the extrusion wheel through swinging to clamp the second wire in the second wire channel, thus putting it into a working state. When the wire limiting mechanism 410 releases the first wire, the first swing mechanism swings to at least one non-working position, causing the first wire limiting mechanism 410 and the first swing mechanism to cooperate with each other. This includes: the first wire limiting mechanism 410 moving relative to the mounting body to abut against the first wire in the first wire channel and restrict the upward movement of the first wire; and / or...

[0122] The first swing mechanism engages with the extrusion wheel to clamp the first wire in the first wire channel, thus putting it into a working state. When the wire limiting mechanism 410 releases the first wire, the second swing mechanism swings to at least one position in the non-working state, so that the second wire limiting mechanism 410 and the second swing mechanism cooperate with each other, including: the second wire limiting mechanism 410 moves relative to the mounting body to abut against the second wire in the second wire channel and restrict the upward movement of the second wire.

[0123] In some embodiments, the switching mechanism includes a first swing mechanism having a first wire channel and a second swing mechanism having a second wire channel, the first swing mechanism rotating about a first rotating shaft 414 and the second swing mechanism rotating about a second rotating shaft 424;

[0124] The distance between the first wire limiting mechanism 410 and the first rotating shaft 414 is L1. In the working state, the distance between the clamping point of the extrusion wheel and the first wire and the first rotating shaft 414 is J1. L1 > J1, ensuring that before the first swing mechanism rotates to completely release the first wire, the first wire limiting mechanism 410 abuts against the first wire, and / or...

[0125] The distance between the second wire limiting mechanism 410 and the second rotating shaft 424 is L2. In the working state, the distance between the clamping point of the extrusion wheel and the second wire and the second rotating shaft 424 is J2. L2 > J2, so that before the second swing mechanism rotates to completely release the second wire, the second wire limiting mechanism 410 abuts against the second wire.

[0126] Understandably, by setting the wire limiting mechanism 410 at a position farther from the clamping point relative to the rotating shaft than the clamping point, the wire limiting mechanism releases the target wire during operation. Furthermore, after the switcher begins to swing or rotate, the movement distance of the wire limiting mechanism 410 is greater than the movement distance of the clamping point. This allows the wire limiting mechanism to engage the target wire before it is completely released, thus minimizing the time the target wire is in a released state from the start of the switching mechanism's release until the wire limiting mechanism engages with the wire. When the target wire is an elastic wire, this ensures the wire remains clamped, reducing the probability of clogging.

[0127] In some embodiments, the filament limiting mechanism 410 mounted on the tool head switches between positions of abutting and releasing the target filament by engaging with other structures other than the tool head. For example, the additive printing tool head is mounted on the 3D printer frame via a trolley and can move in at least one plane. The additive printing tool head engages with the trolley or frame to trigger the filament limiting mechanism 410 to move relative to the mounting body to abut or release the filament.

[0128] Furthermore, the wire limiting mechanism 410 is a spring-type latching mechanism or a push-push mechanism structure. When the wire limiting mechanism 410 and the trolley or frame first cooperate in the trigger position, the locking position is triggered. The locking position causes the wire limiting mechanism 410 to abut against the wire. When the wire limiting mechanism 410 and the trolley or frame cooperate again in the trigger position, the release position is triggered. The release position causes the wire limiting mechanism 410 to release the wire.

[0129] In some embodiments, the wire limiting mechanism 410 cooperates with the trolley or frame at a trigger position to push the wire limiting mechanism 410 to slide or rotate relative to the mounting body, thereby causing the wire limiting mechanism 410 to abut or release the wire.

[0130] In some embodiments, the wire limiting mechanism 410 includes a first wire limiting mechanism 410 corresponding to the first wire and a second wire limiting mechanism 410 corresponding to the second wire, and also includes a limiting mechanism connector that is slidably or rotatably connected to the mounting body. The first wire limiting mechanism 410 and the second wire limiting mechanism 410 are fixedly connected by the limiting mechanism connector.

[0131] The limiting mechanism connector drives the first wire limiting mechanism 410 and the second wire limiting mechanism 410 to move synchronously, so that when the first wire limiting mechanism 410 is in the position of abutting the first wire, the second wire limiting mechanism 410 is in the position of releasing the second wire; when the first wire limiting mechanism 410 is in the position of releasing the first wire, the second wire limiting mechanism 410 is in the position of abutting the second wire.

[0132] It is understandable that by setting a limiting mechanism connector to connect the first wire limiting mechanism 410 and the second wire limiting mechanism 410, the wire limiting mechanism 410 can switch positions of the first wire limiting mechanism 410 and the second wire limiting mechanism 410 with only one trigger or one drive. In some embodiments, when the first wire limiting mechanism 410 abuts against the first wire, the second wire limiting mechanism 410 releases the second wire, and when the first wire limiting mechanism 410 releases the first wire, the second wire limiting mechanism 410 abuts against the second wire.

[0133] In some embodiments, the wire limiting mechanism 410 is installed on the installation body and movably connected to the installation body, or the wire limiting mechanism 410 is installed on the switching mechanism and movably connected to the switching mechanism;

[0134] The wire limiting mechanism 410 includes a wire limiting drive motor and a wire limiting component. The limiting drive motor and the wire limiting component are directly connected in transmission. Alternatively, the wire limiting mechanism 410 includes a wire limiting drive motor and a transmission component. The wire limiting drive motor, the transmission component, and the wire limiting component are sequentially connected in transmission.

[0135] The wire limiting component moves relative to the wire under the drive of the limiting drive motor to abut or release the wire.

[0136] In some embodiments, the wire limiting mechanism 410 is installed on the installation body and movably connected to the installation body, or the wire limiting mechanism 410 is installed on the switching mechanism and movably connected to the switching mechanism;

[0137] The wire limiting mechanism 410 includes an electromagnetic coil, a magnetic conductor, and a wire limiting component. One of the electromagnetic coil or the magnetic conductor is disposed on the wire limiting component, and the other of the electromagnetic coil or the magnetic conductor is disposed on the mounting body or the switching mechanism. The magnetic conductor is a soft magnetic material or a magnet. The wire limiting component moves relative to the mounting body or the switching mechanism under the drive of the electromagnetic coil to abut or release the wire.

[0138] It is understandable that the wire limiting mechanism 410 can also be set as an active component. In this case, the state of the wire limiting mechanism 410 can be flexibly controlled according to the requirements, without relying on the movement of the switching mechanism relative to the installation body or the contact and cooperation between the tool head and other structures other than the tool head.

[0139] Furthermore, the wire limiting mechanism 410 includes an elastic element or a magnetic element and a wire limiting element, wherein the wire limiting element is connected to the elastic element or the magnetic element in a transmission connection or a fixed connection.

[0140] In some embodiments, the wire limiting mechanism 410 is disposed on the target swing mechanism. When the target wire in the target wire channel is clamped and thus in a working state, the elastic member is in either a compressed state or a restored state, so that the wire limiting member is released from the target wire. When the target wire channel is in at least one non-working state, the elastic member is in either a compressed state or a restored state, so that the wire limiting member abuts against the target wire to restrict the upward movement of the target wire in the target wire channel. Alternatively, when the target wire in the target wire channel is clamped and thus in a working state, the magnetic member is in either a released state or an attracted state, so that the wire limiting member is released from the target wire. When the target wire channel is in at least one non-working state, the magnetic member is in either a released state or an attracted state, so that the wire limiting member abuts against the target wire to restrict the upward movement of the target wire in the target wire channel.

[0141] In other embodiments, the wire limiting mechanism 410 is disposed on the mounting body. When the target wire in the target wire channel is clamped and thus in a working state, the elastic member is in either a compressed state or a restored state, so that the wire limiting member is released from the target wire. When the target wire channel is in at least one non-working state, the elastic member is in either a compressed state or a restored state, so that the wire limiting member abuts against the target wire to restrict the upward movement of the target wire in the target wire channel. Alternatively, when the target wire in the target wire channel is clamped and thus in a working state, the magnetic member is in either a released state or an attracted state, so that the wire limiting member is released from the target wire. When the target wire channel is in at least one non-working state, the magnetic member is in either a released state or an attracted state, so that the wire limiting member abuts against the target wire to restrict the upward movement of the target wire in the target wire channel.

[0142] When the target wire channel is the first wire channel, the target wire is the first wire, and the target swing mechanism is the first swing mechanism; when the target wire channel is the second wire channel, the target wire is the second wire, and the target swing mechanism is the second swing mechanism.

[0143] In some embodiments, the wire limiting mechanism 410 includes an elastic element and a wire limiting element, wherein the wire limiting element and the elastic element are connected in a transmission manner or in a fixed manner.

[0144] The wire limiting mechanism 410 is provided on the target swing mechanism or the mounting body. One end of the elastic element abuts against the target swing mechanism or the mounting body, and the other end of the elastic element is connected to the wire limiting element. When the target wire in the target wire channel is clamped and thus in a working state, the elastic element or the wire limiting element is abutted by the target swing mechanism or the mounting body, so that the elastic element is in either a compressed state or a restored state, so that the wire limiting element is released from the target wire.

[0145] When the target wire channel is in at least one non-working position, the elastic element or wire limiting element disengages from the target swing mechanism or mounting body, so that the elastic element is in either a compressed state or a restored state, and the wire limiting element abuts against the target wire to restrict the upward movement of the target wire within the target wire channel.

[0146] In some embodiments, the wire limiting mechanism 410 includes a magnetic element and a wire limiting element, wherein the wire limiting element and the magnetic element are connected in a transmission manner or in a fixed manner.

[0147] The wire limiting mechanism 410 is set on the target swing mechanism or the mounting body. When the target wire in the target wire channel is clamped and thus in working state, the magnetic component is in one of the repulsive, natural, or adsorption states, or the wire limiting component is abutted by the target swing mechanism or the mounting body, so that the wire limiting component is released from the target wire.

[0148] When the target wire channel is in at least one non-working position, the magnetic component is in a repulsive or natural state and an adsorption state, or the wire limiting component is disengaged from the target swing mechanism or the mounting body, so that the wire limiting component abuts against the target wire to restrict the upward movement of the target wire in the target wire channel.

[0149] In some embodiments, the switching mechanism includes a first pressure roller disposed on a first swing mechanism and a second pressure roller disposed on a second swing mechanism. When the target pressure roller and the extrusion roller approach each other, the target wire is clamped and thus in a working state. When the target pressure roller and the extrusion roller move away from each other, the extrusion mechanism releases the clamping of the target wire. Specifically, when the target wire is a first wire, the target pressure roller is the first pressure roller; when the target wire is a second wire, the target pressure roller is the second pressure roller. Furthermore, when the first pressure roller and the extrusion roller approach each other and the first wire is clamped and thus in a working state, the second pressure roller moves away from the extrusion roller to release the clamping of the second wire; when the second pressure roller and the extrusion roller approach each other and the second wire is clamped and thus in a working state, the first pressure roller moves away from the extrusion roller to release the clamping of the first wire.

[0150] In some embodiments, the first swing mechanism (406) includes a first switching part (411), a first hinge part (412), a first pressure roller (413), and a first swing pivot part (414) arranged sequentially from top to bottom; the second swing mechanism (407) includes a second switching part (421), a second hinge part (422), a second pressure roller (423), and a second swing pivot part (424) arranged sequentially from top to bottom; one end of the elastic element (408) is connected to the first hinge part (412), and the other end is connected to the second hinge part (422). The switching mechanism (4) also includes a switching motor (401), a switching motor reduction mechanism (402), a first transmission gear (403), a second transmission gear (404), a switching cam (405), and an elastic element (408); the first transmission gear (403), the second transmission gear (404), the first swing mechanism (406), the second swing mechanism (407), and the elastic element (408) are all mounted on the mounting body; the first transmission gear (403) and the second transmission gear (404) are meshed and connected, and the second transmission gear (404) drives the switching cam (405) to swing; the switching cam (405) is centrally located on the mounting body and above the first reduction gear (304); the first swing mechanism (406) and the second swing mechanism (407) are symmetrically arranged on both sides of the switching cam (405).

[0151] In some embodiments, the switching mechanism and the extrusion mechanism cooperate to allow the first wire in the first wire channel and the second wire in the second wire channel to work alternately; it also includes a first cover, which is disposed on the mounting body; the first cover is provided with a first limiting member and a second limiting member; when the first wire channel is in at least one non-working position, the first limiting member cooperates with the first wire limiting mechanism to restrict the upward movement of the first wire in the first wire channel; when the second wire channel is in at least one non-working position, the second limiting member cooperates with the second wire limiting mechanism to restrict the upward movement of the second wire in the second wire channel.

[0152] To more clearly illustrate the embodiments of this application, please refer to Figures 23-29, which are schematic diagrams of application scenarios in some embodiments of this application.

[0153] As shown in Figures 24 and 25, in this embodiment of the application, the wire limiting mechanism 410 can be driven by an external force, such as driving the rack above the wire limiting mechanism 410, or the wire limiting mechanism 410 can be triggered by an external force to slide or rotate, thereby causing part of the wire limiting mechanism 410 to be stuck inside the left or right wire to restrict the wire from retracting, or to be pulled out from inside the left or right wire.

[0154] As shown in Figures 26 and 27, in this embodiment, the wire limiting mechanism 410 can move along the axial direction of the wire under the influence of external force. Furthermore, as shown in the left side of Figure 26 and the left side of Figure 27, when the left wire limiting mechanism 410 moves upward, its sides are no longer abutted by the left and right side structures, and the left wire limiting mechanism 410 returns to its state of releasing the abutment against the left wire under its own elasticity. Conversely, as shown in the right side of Figure 26 and the right side of Figure 27, when the right wire limiting mechanism 410 moves downward, after its sides are abutted by the left and right side structures, the right wire limiting mechanism 410 abuts against the right wire.

[0155] As shown in Figures 28 and 29, in this embodiment, the wire limiting mechanism 410 can rotate under the influence of external force, thereby abutting against or releasing the wire. For example, as shown in Figures 28 and 29, after the left-hand wire limiting mechanism 410 rotates or slides in a first direction, the left-hand wire limiting mechanism 410 releases its contact with the left-hand wire. Similarly, as shown in Figures 28 and 29, after the right-hand wire limiting mechanism 410 rotates or slides in a second direction, the right-hand wire limiting mechanism 410 abuts against the right-hand wire.

[0156] Furthermore, as shown in Figure 31, in this embodiment, the wire limiting mechanism 410 can be located at a distance from the pivot. In other words, the distance between the wire limiting mechanism 410 and the first swing pivot 414 and the second swing pivot 424 is greater than the distance between the first pressure roller 413 and the first swing pivot 414, and the distance between the second pressure roller 413 and the second swing pivot 424. In other words, the pivot of the wire limiting mechanism 410 is longer than the pivot of the first pressure roller or the second pressure roller. Thus, when the swing mechanism swings at the same swing angle, the distance the wire moves relative to the wire limiting mechanism is longer than the distance the wire moves relative to the pressure roller. Therefore, the wire limiting mechanism 410 can abut against the wire even when the first pressure roller or the second pressure roller is not completely separated from the wire.

[0157] As shown in Figures 17-22, the wire channel includes a first wire channel and a second wire channel; the switching mechanism and the extrusion mechanism cooperate to allow the first wire in the first wire channel and the second wire in the second wire channel to work alternately; it also includes a first cover 11, which is disposed on the mounting body; the first cover 11 is provided with a first limiting member 431 and a second limiting member 432; the first swing mechanism 406 is provided with a first wire limiting mechanism 441, and the second swing mechanism 407 is provided with a second wire limiting mechanism 442; when the first wire channel is in at least one position of non-working state, the first limiting member 431 cooperates with the first wire limiting mechanism 441 to restrict the first wire in the first wire channel from moving upward; when the second wire channel is in at least one position of non-working state, the second limiting member 432 cooperates with the second wire limiting mechanism 442 to restrict the second wire in the second wire channel from moving upward. The first limiting member 431 includes a first steel ball 4311 and a first mounting groove 4313, and the second limiting member 432 includes a second steel ball 4321 and a second mounting groove 4323. The first wire limiting mechanism 441 includes a first movable limiting member 4411 and a first limiting structure 4412, and the second wire limiting mechanism 442 includes a second movable limiting member 4421 and a second limiting structure 4422. The first movable limiting member 4411 and the first limiting structure 4412 can be integrally formed or separately formed; the second movable limiting member 4421 and the second limiting structure 4422 can be integrally formed or separately formed. The first mounting groove 4313 and the second mounting groove 4323 are disposed on the first cover 11; the first limiting member 431 is disposed opposite to the first wire channel, and the second limiting member 432 is disposed opposite to the second wire channel; the first wire limiting mechanism 441 is disposed on the first swing mechanism 406, and the second wire limiting mechanism 442 is disposed on the second swing mechanism 407; when the first wire channel is at the end position of the non-working state, the first limiting member 431 abuts against the first wire limiting mechanism 441; when the second wire channel is at the end position of the non-working state, the second limiting member 432 abuts against the second wire limiting mechanism 442. When the first wire channel or the second wire channel is in the working state, the first wire limiting mechanism 441 or the second wire limiting mechanism 442 returns to the position that does not restrict the upward movement of the wire under the action of the wire or elastic element.

[0158] Specifically, the first limiting structure 4412 or the second limiting structure 4422 is a cutting edge, tip, protrusion, or other structure disposed at the end of the first movable limiting member 4411 or the second movable limiting member 4421, capable of engaging the wire, used to restrict the upward movement of the wire at the end position in the non-working state. In one embodiment, the first limiting structure 4412 or the second limiting structure 4422 is a one-way limiting structure. Specifically, the first limiting structure 4412 and the second limiting structure 4422 are downwardly extending tooth-like, hook-like, or claw-like structures. The first limiting structure 4412 or the second limiting structure 4422 has a slope or arc surface and a cutting edge or tip for engaging the wire. When the wire moves from top to bottom, it can act on the slope or arc surface, causing the one-way limiting structure to move away from the wire. When the wire moves from bottom to top, the wire is engaged by the cutting edge or tip for engaging the wire, restricting its movement.

[0159] It also includes a first elastic mechanism 4312 and a second elastic mechanism 4322. One end of the first elastic mechanism 4312 is disposed in the first mounting groove 4313, and the other end is connected to a first steel ball 4311. One end of the second elastic mechanism 4322 is disposed in the second mounting groove 4323, and the other end is connected to a second steel ball 4321. The first steel ball 4311 and the second steel ball 4321 both protrude at least partially from the first mounting groove 4313 and the second steel ball 4321, respectively. When the first wire channel is in at least one non-working position, the first steel ball 4311 abuts against the first movable limiting member 4411, causing the first limiting structure 4412 to at least partially enter the first wire channel and compress the first wire. When the second wire channel is in at least one non-working position, the second steel ball 4321 abuts against the second movable limiting member 4421, causing the second limiting structure 4422 to at least partially enter the second wire channel and compress the second wire. The first elastic mechanism 4312 and the second elastic mechanism 4322 are springs. By setting an elastic mechanism, the force applied during the pushing process can be made gentler, reducing the chance of jamming and increasing the service life of the first wire limiting mechanism 441 or the second wire limiting mechanism 442.

[0160] It also includes a first elastic reset member 4413 disposed on the first swing mechanism 406, and a second elastic reset member 4423 disposed on the second swing mechanism 407; one end of the first elastic reset member 4413 is connected to the first movable limiting member 4411, and the other end is connected to the first swing mechanism 406. When the first wire channel is in the working state or between the working state and the end position of the non-working state, the first movable limiting member 4411 moves away from the wire under the action of the first elastic reset member 4413; one end of the second elastic reset member 4423 is connected to the second movable limiting member 4421, and the other end is connected to the second swing mechanism 406. When the second wire channel is in the working state or between the working state and the end position of the non-working state, the second movable limiting member 4421 moves away from the wire under the action of the second elastic reset member 4423.

[0161] It should be noted that, through the limiting function of the wire limiting mechanism, the wire in the non-working state will be reliably fixed and will not be pulled by external forces (such as tool head movement, wire guide tube shaking, etc.). This avoids inaccurate control of the spray volume in the next spray and also prevents the problem of some melted but not completely solidified wire being pulled into the throat of the hot end and thus clogging the spray head.

[0162] The relevant structure and working principle of the cutting mechanism are as follows:

[0163] As shown in Figures 12-16, the cutting mechanism includes a first cutting mechanism 81 and a second cutting mechanism 82; the first cutting mechanism includes a first cutting blade 811, a first cutting blade rod 812, and a first cutting blade shaft 813; the second cutting mechanism 82 includes a second cutting blade 821, a second cutting blade rod 822, and a second cutting blade shaft 823; a first swing pivot 414 is arranged adjacent to the first cutting blade shaft 813; and a second swing pivot 424 is arranged adjacent to the second cutting blade shaft 823. The first cutting bar 812 and the second cutting bar 822 are located on the second side of the mounting body, and are arranged opposite to each other. The first cutting bar 812 is provided with a first cutting trigger point 8121, a first cutting shaft mounting part 8122, and a first cutting mounting part 8123 in sequence from top to bottom. The second cutting bar 822 is provided with a second cutting trigger point 8221, a second cutting shaft mounting part 8222, and a second cutting mounting part 8223 in sequence from top to bottom. The distance between the first cutting trigger point 8121 and the first cutting shaft mounting part 8122 is greater than the distance between the first cutting shaft mounting part 8123 and the first cutting shaft mounting part 8122, and the distance between the second cutting trigger point 8221 and the second cutting shaft mounting part 8222 is greater than the distance between the second cutting shaft mounting part 8223 and the second cutting shaft mounting part 8222. The first cutter 811 includes a first blade 8111, a first blade holder 8112, and a first pulling rod 8113. The second cutter 821 includes a second blade 8211, a second blade holder 8212, and a second pulling rod 8213. The first blade 8111 is disposed inside the first blade holder 8112, with its cutting edge facing the first cutter rod 812. The second blade 8211 is disposed inside the second blade holder 8212, with its cutting edge facing the second cutter rod 822. The first cutter is located between the first cutter shaft and the first nozzle, and the second cutter is located between the second cutter shaft and the second nozzle. It should be noted that in the layout of the extrusion mechanism, switching mechanism, and cutting mechanism in this embodiment, due to the need to achieve switching and lifting of the dual nozzles, as well as the arrangement of the cutter, and considering the multiple requirements of not wanting wire overflow from the nozzle after operation, the switching cam is positioned close to the switching motor and at the top, while the pivot of the swing mechanism is positioned at the bottom, leaving the middle position for the extrusion wheel and the cutter, thereby achieving near-end extrusion and near-end cutting. The shorter the distance from the extrusion wheel to the hot end of the nozzle, the better. If the distance is longer, the control of the extrusion volume is more easily affected by wire deformation. The farther the cutter position is, the more material is wasted during material change. The distance between the cutter trigger point and the cutter shaft is greater than the distance between the cutter and the cutter shaft (force amplification effect), achieving effortless cutting. Simultaneously, the cutter shaft is positioned close to the pivot of the swing mechanism, avoiding the cutter occupying space in the lower hot-end air duct, which is beneficial for heat dissipation. Furthermore, the blade being encased inside the cutter is also safer.

[0164] The system also includes a guide cover 12, a follower slider 53, and a guide rail 54. The follower slider 53 has a sliding groove 531 on one side and slides in cooperation with the guide rail 54. The guide rail 54 is mounted on the guide cover 12, which is at least partially located below the extrusion wheel. The follower slider 53 has a sliding cavity 532 in a horizontal direction, and the first cutter 811 is slidably disposed in the sliding cavity 532. The first cutter mounting portion 8123 includes a receiving portion 8000 movably connected to the first pulling protrusion 8113. When the first pulling protrusion 8113 is in the first working position, it is located within the receiving portion 8000, and the first cutter 811 can be pulled by the first cutter rod 812. When the first pulling protrusion 8113 is at least in the second working position, it is located outside the receiving part 8000, and the first cutting rod 812 cannot pull the first cutting blade 811. The receiving part 8000 has an upper opening structure, and the first pulling protrusion 8113 enters or leaves the receiving part 8000 through the upper opening. The receiving part is a component that drives the first pulling protrusion to move. The receiving part 8000 can be a U-shaped opening groove, or it can be a structure with a wall thickness that decreases from bottom to top. The thicker lower wall can block the first pulling protrusion, so that the receiving part can drive the first pulling protrusion to move. The thinner upper wall can avoid the first pulling protrusion, so as to ensure that the first pulling protrusion can disengage from the receiving part.

[0165] The sliding groove 531 is a dovetail groove. It also includes a first guide member 55 and a second guide member 56, which are fixedly mounted on the guide cover 12 and used to guide the first wire and the second wire, respectively. The guide cover 12 also has a sliding positioning part 121, which guides the sliding of the second cutter 821. The follower slider 53 has a sliding channel 533, and the first guide member 55 slides in conjunction with the sliding channel 533 of the follower slider 53. It also includes a compression spring 57, which has a compression spring mounting part 534 on the follower slider 53. One end of the compression spring 57 is fixed or abuts against the guide cover 12, and the other end is located within the compression spring mounting part 534. The compression spring on the follower slider keeps it pressed against the movable hot end. This ensures the cutter can move up and down with the hot end and also keeps it pressed in place, preventing the drive slider from failing to fall smoothly due to unforeseen circumstances. This would prevent the preload magnetic element from suddenly attracting the drive block, reducing the impact noise when the drive slider contacts the positioning block at the bottom working position. Furthermore, by positioning the cutter's pivot above the cutter, the cutter moves up and down with the first nozzle, ensuring the cutting point is as close as possible to the hot end of the nozzle. Positioning the pivot above the cutter also ensures the cutter can move downwards relative to the cutter rod without being obstructed by the pivot.

[0166] When the switching mechanism is running, when the switching cam 405 applies a biasing force to the second switching part 421, the second pressure roller 423 moves away from the extrusion roller 303, and the first pressure roller 413 moves closer to the extrusion roller 303, thus cooperating to convey the first wire; when the switching cam 405 applies a biasing force to the first switching part 411, the first pressure roller 413 moves away from the extrusion roller 303, and the second pressure roller 423 moves closer to the extrusion roller 303, thus cooperating to convey the second wire.

[0167] In the process of printing a target object using an additive printer with an additive printing toolhead as described above, the consumables typically refer to the materials used in the process, that is, the basic raw materials that are built up layer by layer to form a three-dimensional object through specific techniques. The type and characteristics of the consumables directly affect the performance, accuracy, and application scenarios of the printed product. Therefore, users can comprehensively select consumables based on printing technology, functional requirements, and cost budget to ensure that the printed items are suitable for the application scenarios.

[0168] For example, fused deposition modeling (FDM) additive printers typically use filaments, also known as filaments, with diameters of 1.75 mm or 2.85 mm. Furthermore, to ensure the stability of the object, filaments made of PLA (Polylactic Acid) can be used to print objects such as models, educational supplies, and household items.

[0169] Based on the aforementioned potential problems, please refer to Figure 23. This application provides a method for controlling an additive printing toolhead. The toolhead includes a first nozzle 51, a second nozzle 52, an extrusion mechanism 3, a switching mechanism 4, and a filament limiting mechanism. The method includes:

[0170] 01: The wire limiting mechanism abuts against the current wire of the target nozzle to restrict the retraction of the current wire, wherein the target nozzle is the first nozzle 51 or the second nozzle 52;

[0171] 02: Control switching mechanism 4 cooperates with extrusion mechanism 3 to make extrusion mechanism 3 loosen the clamp on the current wire;

[0172] 03: Before clamping the filament with the switching mechanism 4 and the extrusion mechanism 3 again for printing, release the filament limiting mechanism from contact with the current filament.

[0173] This application also provides an additive printing tool head, which includes a memory and a processor. The control method of the additive printing tool head of this application can be implemented by the additive printing tool head of this application. Specifically, the memory stores a computer program, and the processor is used to cause the filament limiting mechanism to abut against the current filament of the target nozzle to limit the retraction of the current filament, and to control the switching mechanism 4 to cooperate with the extrusion mechanism 3 to cause the extrusion mechanism 3 to release the clamping of the current filament, and to cause the filament limiting mechanism to release the abutment of the current filament before the switching mechanism 4 and the extrusion mechanism 3 clamp the filament again for printing, wherein the target nozzle is a first nozzle 51 or a second nozzle 52.

[0174] Specifically, to prevent the molten filament from retracting to the heat break in the throat and solidifying into a hard lump when printing with elastic materials, thereby blocking the throat channel, in this embodiment, the tool head can use a pre-set filament limiting mechanism to abut against the current filament of the target printhead, so that the filament limiting mechanism hinders the movement of the current filament and thus prevents the current filament from retracting into the throat.

[0175] More specifically, in the embodiments of this application, the tool head can cause the wire limiting mechanism to abut against the current wire of the target nozzle to restrict the movement of the current wire.

[0176] Next, when the wire limiting mechanism comes into contact with the current wire of the target nozzle, making it difficult for the current wire to move, the tool head can control the switching mechanism 4 to operate so that the extrusion mechanism 3 can release the clamp on the current wire.

[0177] Before the tool head can control the switching mechanism 4 to operate so that the extrusion mechanism 3 releases its clamp on the current wire, the tool head can control the first cutter 811 and the second cutter 821 to perform actions, such as controlling the first cutter 811 or the second cutter 821 to cut the current wire. It can be understood that when the extrusion mechanism 3 clamps the current wire, the current wire is difficult to move. After the first cutter 811 or the second cutter 821 cuts the current wire, the extruder releasing its clamp on the current wire will no longer cause the wire to retract and thus prevent clogging.

[0178] In one example, the target printhead is the printhead that is performing a printing job in the first printhead 51 and the second printhead 52.

[0179] In one example, the current filament refers to the filament used by the target printhead for the printing job.

[0180] In one example, the filament limiting mechanism is a device independent of the additive printing tool. For instance, if the cover of the additive printing tool head has two through holes, one of which allows the filament in the first nozzle to pass through and the other of which allows the filament in the second nozzle to pass through, then the filament limiting mechanism can be a device independent of the additive printing tool that can pass through the through holes to abut against the filament, thereby limiting the movement of the filament.

[0181] In one example, the wire limiting mechanism can be a cutting edge, tip, protrusion, or downward-extending toothed, hooked, or claw-like structure that abuts the wire.

[0182] Thus, in this embodiment, the filament limiting mechanism can abut against the current filament of the target printhead to restrict the retraction of the current filament, and the switching mechanism 4 can cooperate with the extrusion mechanism 3 to loosen the clamping of the current filament. Before the switching mechanism 4 and the extrusion mechanism 3 clamp the filament again for printing, the filament limiting mechanism loosens its abutment against the current filament. Therefore, from the time the current filament of the target printhead is loosened until the target printhead and the extrusion mechanism 3 are clamped again for printing, the movement of the current filament is restricted by the filament limiting mechanism, thereby preventing the current filament from retracting into the throat and causing a clogging.

[0183] In some embodiments of this application, when the wire of one of the first nozzles 51 and the second nozzle 52 is brought into contact, the wire of the other nozzle is released.

[0184] Specifically, in this embodiment, when the filament of the first printhead 51 is engaged, the filament of the second printhead 52 is disengaged. For example, when the filament limiting mechanism engages with the filament of the first printhead 51 to restrict the retraction of the filament in the first printhead 51, the filament in the second printhead 52 is not engaged with the filament limiting mechanism. Conversely, when the filament limiting mechanism engages with the filament of the second printhead 52 to restrict the retraction of the filament in the second printhead 52, the filament in the first printhead 51 is not engaged with the filament limiting mechanism. Thus, while one printhead is performing a printing operation using the current filament, the other printhead remains relatively stationary relative to the filament in that printhead.

[0185] Thus, in this embodiment of the application, when the wire of one of the first printhead 51 and the second printhead 52 is engaged, the wire of the other printhead is disengaged, thereby ensuring the stability of the dual printheads during printing operations.

[0186] The problem of filament pullback can further increase the probability of nozzle blockage when printing with elastic materials. For example, when printing wear-resistant, impact-resistant, and flexible features, filaments made of TPU (Thermoplastic Polyurethane) can be used to print objects such as shock-absorbing pads, soft rubber parts, watch straps, joint models, and springs.

[0187] For filaments made of elastic materials such as TPU, these filaments have high elasticity. After the extrusion mechanism releases the filament, the end of the filament will usually experience a large pullback due to its own elasticity. This will have a certain probability of causing the molten filament in the nozzle below the extrusion mechanism to retract to the throat (heat break) to cool and solidify, forming a hard lump, which will then block the throat channel.

[0188] In some embodiments of this application, the wire limiting mechanism includes an abutment mechanism and a wire limiting device, a tool head switching mechanism 4 and a first cover 11, the wire limiting device is disposed on the switching mechanism 4, and the first cover 11 is provided with an abutment portion. Step 01 includes:

[0189] The contact mechanism is controlled to move to the first position so that it contacts the current wire of the target nozzle to limit the retraction of the current wire, wherein the target nozzle is the first nozzle 51 or the second nozzle 52;

[0190] And, step 02 includes:

[0191] The control switching mechanism 4 cooperates with the extrusion mechanism 3 to loosen the clamping of the current wire by the extrusion mechanism 3, and to make the wire limiting device contact the abutment part to clamp the current wire.

[0192] Specifically, in the embodiments of this application, the wire limiting mechanism may include an abutting mechanism and a wire limiting device disposed on the switching mechanism 4. The additive printing tool head may utilize the abutting mechanism, the switching mechanism 4 and the extrusion mechanism 3 in sequence, so that the wire currently in use in the additive printing tool head is first abutted by the abutting mechanism to prevent the current wire from moving.

[0193] In some embodiments, the contact mechanism is the aforementioned cutting mechanism, and the tool head can control the first cutter 811 or the second cutter 821 in the cutting mechanism to travel to a first position so that the cutter reaching the first position can contact the current wire of the target nozzle to restrict the movement of the current wire.

[0194] Next, when the current wire is in contact with the first cutter 811 or the second cutter 821 and thus the wire is difficult to move, the tool head can control the switching mechanism 4 to operate so that the extrusion mechanism 3 releases the clamp on the current wire, and makes the wire limiting device of the switching mechanism 4 contact the contact portion of the first cover 11 to tighten the current wire, thereby restricting the movement of the current wire.

[0195] In one example, the first cutter 811 can abut against the wire in the first nozzle 51 to restrict the movement of the wire in the first nozzle 51, and the second cutter 821 can abut against the wire in the second nozzle 52 to restrict the movement of the wire in the second nozzle 52.

[0196] In one example, the abutting portion of the first cover 11 refers to a part of the body of the first cover 11, such as the convex portion of the body of the first cover 11. In another example, the abutting portion of the first cover 11 refers to a component that is separately disposed from the first cover 11. In some embodiments, the abutting portion of the first cover 11 is the first limiting member 431 or the second limiting member 432 described above, and the wire limiting device is the first wire limiting mechanism 441 or the second wire limiting mechanism 442 described above, which will not be described again here.

[0197] Thus, in this embodiment, the cutting mechanism can be controlled to travel to the first position so that the cutting mechanism abuts against the current wire of the target nozzle to limit the retraction of the current wire. If the current wire is difficult to retract due to the abutment of the cutting mechanism, the switching mechanism 4 is controlled to cooperate with the extrusion mechanism 3 so that the extrusion mechanism 3 releases the clamp on the current wire and the wire limiting device contacts the abutment part to clamp the current wire. This forms two abutments. Between the switching mechanism from the switching start point to the switching end point where the wire limiting device abuts against the wire, the wire is also in an abutment state, ensuring that the wire is abutted throughout the switching process, which can prevent the current wire from retracting into the throat and causing a blockage.

[0198] In some embodiments of this application, step 01 includes:

[0199] Control the wire limiting mechanism or tool head to move to the first position so that the wire limiting mechanism abuts against the current wire;

[0200] And, step 03 includes:

[0201] Before the switching mechanism 4 and the extrusion mechanism 3 clamp the filament again for printing, control the filament limiting mechanism or the tool head to move to the second position or move back to the first position, so that the filament limiting mechanism releases its contact with the current filament.

[0202] The processor in this embodiment is also used to control the wire limiting mechanism or the tool head to travel to a first position so that the wire limiting mechanism abuts against the current wire, and to control the wire limiting mechanism or the tool head to travel to a second position or to travel to the first position again before the switching mechanism 4 and the extrusion mechanism 3 clamp the wire again for printing, so that the wire limiting mechanism releases its abutment against the current wire.

[0203] Specifically, in this embodiment, the wire limiting mechanism or tool head can be controlled to travel to a first position so that the wire limiting mechanism abuts against the current wire, thereby restricting the current limit from moving, such as retracting. Furthermore, the wire limiting mechanism or tool head can be controlled to move to a second position, or to move from the first position to another position, or to make a reciprocating motion based on the first position, thereby releasing the wire limiting mechanism from abutting the current wire.

[0204] In one example, when the wire limiting mechanism is engaged with the current wire, if the wire limiting mechanism or the tool head moves once, the wire limiting mechanism can release its engagement with the current wire after the movement. Conversely, when the wire limiting mechanism releases its engagement with the current wire, if the wire limiting mechanism or the tool head moves once, it will engage with the current wire again after the movement.

[0205] In one example, the wire limiting mechanism includes the first cutter 811, the first cutter bar 812, the second cutter 821, and the second cutter bar 822 described above. The first cutter bar 812 and the second cutter bar 822 can change their stroke as the tool head moves. Furthermore, if the stroke of the cutter bar is small, the stroke by which the cutter bar drives the cutter to move is also small, thereby causing part of the cutter to enter the consumable to abut against the current wire without cutting it.

[0206] In one example, the wire limiting mechanism is a spring-loaded latching mechanism that uses an insertion and ejection locking mechanism (or push-push mechanism) to actuate the wire with one trigger / displacement and release the wire with another trigger / displacement.

[0207] Thus, in this embodiment, the wire limiting mechanism or tool head can be controlled to move to a first position so that the wire limiting mechanism abuts against the current wire, and the wire limiting mechanism or tool head can be moved to a second position so that the wire limiting mechanism releases its abutment against the current wire, thereby realizing the current wire abutment or release based on position movement.

[0208] In some embodiments of this application, the wire limiting mechanism includes a drive member and a wire limiting member, causing the wire limiting mechanism to abut against the current wire of the target nozzle to limit the retraction of the current wire, including:

[0209] The control drive unit drives the wire limiting member to the first position so that the wire limiting member abuts against the current wire;

[0210] Before the switching mechanism 4 and the extrusion mechanism 3 clamp the filament again for printing, the filament limiting mechanism releases its contact with the current filament, including:

[0211] Before the switching mechanism 4 and the extrusion mechanism 3 clamp the filament again for printing, the control drive drives the filament limiter to the second position, causing the filament limiter to release its contact with the current filament.

[0212] The processor in this embodiment is also configured to control the drive member to drive the wire limiting member to a first position so that the wire limiting member abuts against the current wire, and to control the drive member to drive the wire limiting member to a second position before the switching mechanism 4 and the extrusion mechanism 3 clamp the wire again for printing, so that the wire limiting member releases its abutment against the current wire.

[0213] Specifically, in the embodiments of this application, the wire limiting mechanism includes a driving member and a wire limiting member. The driving member can drive the wire limiting member to move to a first position or a second position, so that the wire limiting member abuts against the current wire, or the wire limiting member releases its abutment against the current wire.

[0214] In one example, the driving element includes a power source such as a motor or electromagnet, which can transmit power to the wire limiting member to cause displacement of the wire limiting member. For example, when the driving element includes an electromagnet, the electromagnet can drive a transmission mechanism such as a crank or slider to switch between two positions, or the electromagnet can attract and reset under other elastic forces, gravity, or magnetic forces, thereby causing the transmission mechanism such as the crank or slider to drive the wire limiting member to abut against the current wire, or to release the abutment against the current wire. As another example, when the driving element includes a drive motor, the drive motor can drive the wire limiting member to perform linear or rotational motion, thereby abutting against the current wire, or releasing the abutment against the current wire.

[0215] In one example, the driving component includes switching devices such as electronic switches, which can change the position state of the wire limit component according to its own opening and closing state.

[0216] Thus, in this embodiment, the driving component can be controlled to drive the wire limiting component to the first position so that the wire limiting component abuts against the current wire. Before the switching mechanism 4 and the extrusion mechanism 3 clamp the wire again for printing, the driving component can be controlled to drive the wire limiting component to the second position so that the wire limiting mechanism releases its abutment against the current wire. This allows the abutment and release of the current wire and the wire limiting component to be achieved based on the driving component, thereby ensuring the robust execution of the abutment or release of the current wire and the wire limiting component.

[0217] In some embodiments of this application, the driving component includes a wire limiting drive motor, which is directly connected to the wire limiting member; or, the driving component includes a wire limiting drive motor and a transmission member, which are sequentially connected in a transmission manner.

[0218] Specifically, in the embodiments of this application, the driving component of the wire limiting mechanism may include a wire limiting drive motor. Furthermore, the wire limiting drive motor may be directly connected to the wire limiting component, so that the wire limiting drive motor can directly transmit power to the wire limiting component to cause the wire limiting component to move, thereby ensuring efficient power transmission between the wire limiting drive motor and the wire limiting component to a certain extent.

[0219] Furthermore, in the embodiments of this application, the driving component of the wire limiting mechanism may include a wire limiting drive motor and a transmission component. The wire limiting drive motor can be connected to the wire limiting component through the transmission component. Therefore, the wire limiting drive motor can control the movement of the wire limiting component through the transmission component, which can ensure transmission accuracy to a certain extent, facilitate closed-loop control, and thus ensure the accuracy of the displacement of the wire limiting component.

[0220] Thus, in the embodiments of this application, the driving component can be implemented based on a wire limit drive motor, or based on a wire limit drive motor and a transmission component, thereby ensuring robust control of the wire limit component by the driving component.

[0221] In some embodiments of this application, the step of controlling the contact mechanism to move to the second position and release the contact with the current wire includes:

[0222] Before the contacting mechanism moves to the second position and releases its contact with the current wire, the contacting mechanism moves to the third position to cut off the current wire.

[0223] The processor in this embodiment is further configured to control the abutment mechanism to move to a third position to cut off the current wire before controlling the abutment mechanism to move to a second position and release the abutment on the current wire.

[0224] Specifically, in this embodiment of the application, before the tool head contacts the wire limiting mechanism of the switching mechanism 4 and the abutment part of the first cover 11 to clamp the current wire, the tool head can first control the abutment mechanism to move to the third position to cut the current wire.

[0225] In one example, when the switching mechanism 4 clamps the wire with the extrusion mechanism 3, it can proceed to the third position to cut the current wire.

[0226] Furthermore, after the contacting mechanism moves to the third position to cut the current wire, the tool head can control the contacting mechanism to move to the second position to release the current wire, thereby completing a wire cutting operation.

[0227] Thus, in this embodiment, when the switching mechanism 4 and the extrusion mechanism 3 are clamping the wire, the abutting mechanism is first controlled to move to the third position to cut the current wire, and then the abutting mechanism is controlled to move to the second position to release the abutment on the current wire, thereby completing the cutting operation of the current wire. At the same time, because the current wire is clamped due to the cooperation between the switching mechanism 4 and the extrusion mechanism 3 during the cutting process of the abutting mechanism, the cut end of the current wire is unlikely to spring back to the throat or other components, thereby ensuring the stable execution of the cutting operation of the current wire.

[0228] This application also provides an additive printer that includes the additive printing tool head described above.

[0229] In this specification, the terms "specifically," "furthermore," "particularly," "understandably," etc., refer to specific features, structures, materials, or characteristics described in connection with embodiments or examples that are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0230] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0231] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An additive printing toolhead, comprising a mounting body, a first printhead, a second printhead, and a filament channel; wherein: The main body of the installation is provided with an extrusion mechanism (3) and a switching mechanism (4), and the switching mechanism is movably connected to the main body of the installation. The wire channel includes a first wire channel and a second wire channel. The switching mechanism and the extrusion mechanism cooperate to intermittently clamp or release the first wire in the first wire channel, or the switching mechanism and the extrusion mechanism cooperate to intermittently clamp or release the second wire in the second wire channel. The first nozzle is used to receive the first wire conveyed downward through the first wire channel, and the second nozzle is used to receive the second wire conveyed downward through the second wire channel. It also includes a wire limiting mechanism installed on the installation body or switching mechanism. When the target wire in the target wire channel is in at least one position in the non-working state, the wire limiting mechanism abuts against the target wire in the target wire channel to restrict the target wire from moving upward. The non-working state is the state in which the target wire is partially or completely released by the switching mechanism and the extrusion mechanism. The target wire channel is either the first wire channel or the second wire channel. When the target wire channel is the first wire channel, the target wire is the first wire; when the target wire channel is the second wire channel, the target wire is the second wire.

2. The additive printing tool head according to claim 1, wherein: The extrusion mechanism includes an extrusion motor and an extrusion wheel. The extrusion motor is connected to the extrusion wheel and drives the extrusion wheel to rotate. The switching mechanism includes a first swing mechanism with a first wire channel and a second swing mechanism with a second wire channel. The first swing mechanism and the second swing mechanism are rotatably mounted on the mounting body. When the target swing mechanism swings relative to the mounting body and cooperates with the extrusion wheel in the working state, the target wire in the target wire channel is clamped to convey or retract the target wire, and the wire limiting mechanism releases the target wire. When the target wire channel is the first wire channel, the target swing mechanism is the first swing mechanism; when the target wire channel is the second wire channel, the target swing mechanism is the second swing mechanism.

3. The additive printing tool head according to claim 2, wherein: The wire limiting mechanism includes a cutting edge, tip, protrusion, or downwardly extending toothed, hooked, or claw-like structure that abuts the wire. The wire limiting mechanism moves relative to the wire to abut or release the wire.

4. The additive printing tool head according to claim 3, wherein: The wire limiting mechanism includes a first wire limiting mechanism disposed on and movably connected to the first swing mechanism, and a second wire limiting mechanism disposed on and movably connected to the second swing mechanism; The target swing mechanism swings to at least one position in the non-working state, so that the target wire limiting mechanism and the installation body cooperate with each other to drive the target wire limiting mechanism to abut against the target wire in the target wire channel and restrict the target wire from moving upward. When the target wire channel is the first wire channel, the target wire limiting mechanism is the first wire limiting mechanism; when the target wire channel is the second wire channel, the target wire limiting mechanism is the second wire limiting mechanism.

5. The additive printing tool head according to claim 3, wherein: The wire limiting mechanism is installed on the installation body and is movably connected to the installation body. The wire limiting mechanism includes a first wire limiting mechanism and / or a second wire limiting mechanism. The first swing mechanism swings to at least one non-working position, causing the first wire limiting mechanism to cooperate with the first swing mechanism, including: the first wire limiting mechanism moving relative to the mounting body to abut against the first wire in the first wire channel and restrict the upward movement of the first wire, and / or, The second swing mechanism swings to at least one position in the non-working state, so that the second wire limiting mechanism and the second swing mechanism cooperate with each other, including: the second wire limiting mechanism moves relative to the mounting body to abut against the second wire in the second wire channel and restrict the upward movement of the second wire.

6. The additive printing tool head according to claim 4 or 5, wherein: The second swing mechanism engages with the extrusion wheel through swinging to clamp the second wire in the second wire channel, thus entering a working state. When the wire limiting mechanism releases the first wire, the first swing mechanism swings to at least one non-working position, causing the first wire limiting mechanism and the first swing mechanism to cooperate with each other, including: the first wire limiting mechanism moving relative to the mounting body to abut against the first wire in the first wire channel and restrict the upward movement of the first wire, and / or... The first swing mechanism engages with the extrusion wheel to clamp the first wire in the first wire channel, thus putting it into a working state. When the wire limiting mechanism releases the first wire, the second swing mechanism swings to at least one position in the non-working state, so that the second wire limiting mechanism and the second swing mechanism cooperate with each other, including: the second wire limiting mechanism moves relative to the mounting body to abut against the second wire in the second wire channel and restrict the upward movement of the second wire.

7. The additive printing tool head according to claim 4 or 5, wherein: The switching mechanism includes a first swing mechanism with a first wire channel and a second swing mechanism with a second wire channel. The first swing mechanism rotates around a first pivot, and the second swing mechanism rotates around a second pivot. The distance between the first wire limiting mechanism and the first rotating shaft is L1. In the working state, the distance between the clamping point of the extrusion wheel and the first wire and the first rotating shaft is J1. L1 > J1, ensuring that before the first swing mechanism rotates to completely release the first wire, the first wire limiting mechanism abuts against the first wire, and / or... The distance between the second wire limiting mechanism and the second rotating shaft is L2. In the working state, the distance between the clamping point of the extrusion wheel and the second wire and the second rotating shaft is J2. L2 > J2, so that the second wire limiting mechanism abuts against the second wire before the second swing mechanism rotates to completely release the second wire.

8. The additive printing tool head according to claim 3, wherein: The additive printing tool head is mounted to the 3D printer frame via a trolley and can move in at least one plane. The additive printing tool head cooperates with the trolley or frame to trigger a filament limiting mechanism to move relative to the mounting body to engage or disengage the filament.

9. The additive printing tool head according to claim 8, wherein: The wire limiting mechanism is a spring-loaded latching mechanism or a push-push mechanism. When the wire limiting mechanism and the trolley or frame first engage in the trigger position, they trigger the locking position, causing the wire limiting mechanism to abut the wire. When the wire limiting mechanism and the trolley or frame engage again in the trigger position, they trigger the release position, causing the wire limiting mechanism to release the wire; or... The wire limiting mechanism cooperates with the trolley or frame at the trigger position to push the wire limiting mechanism to slide or rotate relative to the installation body, thereby causing the wire limiting mechanism to abut or release the wire.

10. The additive printing tool head according to claim 9, wherein: The wire limiting mechanism includes a first wire limiting mechanism corresponding to the first wire and a second wire limiting mechanism corresponding to the second wire, and also includes a limiting mechanism connector that is slidably or rotatably connected to the mounting body. The first wire limiting mechanism and the second wire limiting mechanism are fixedly connected through the limiting mechanism connector. The limiting mechanism connector drives the first wire limiting mechanism and the second wire limiting mechanism to move synchronously, so that when the first wire limiting mechanism is in the position of abutting the first wire, the second wire limiting mechanism is in the position of releasing the second wire; when the first wire limiting mechanism is in the position of releasing the first wire, the second wire limiting mechanism is in the position of abutting the second wire.

11. The additive printing tool head according to claim 1, wherein: The wire limiting mechanism is installed on the installation body and is movably connected to the installation body; or, the wire limiting mechanism is installed on the switching mechanism and is movably connected to the switching mechanism. The wire limiting mechanism includes a wire limiting drive motor and a wire limiting component. The limiting drive motor and the wire limiting component are directly connected in transmission. Alternatively, the wire limiting mechanism includes a wire limiting drive motor and a transmission component. The wire limiting drive motor, the transmission component, and the wire limiting component are sequentially connected in transmission. The wire limiting component moves relative to the wire under the drive of the limiting drive motor to abut or release the wire.

12. The additive printing tool head according to claim 1, wherein: The wire limiting mechanism is installed on the installation body and is movably connected to the installation body; or, the wire limiting mechanism is installed on the switching mechanism and is movably connected to the switching mechanism. The wire limiting mechanism includes an electromagnetic coil, a magnetic conductor, and a wire limiting component. One of the electromagnetic coil or the magnetic conductor is disposed on the wire limiting component, and the other of the electromagnetic coil or the magnetic conductor is disposed on the mounting body or the switching mechanism. The magnetic conductor is a soft magnetic material or a magnet. The wire limiting component moves relative to the mounting body or the switching mechanism under the drive of the electromagnetic coil to abut or release the wire.

13. The additive printing tool head according to claim 2, wherein: The wire limiting mechanism includes an elastic or magnetic component and a wire limiting component, which is either connected to the elastic or magnetic component in a transmission or fixed manner. A wire limiting mechanism is disposed in the target swing mechanism. When the target wire in the target wire channel is clamped and thus in a working state, the elastic element is in either a compressed state or a restored state, so that the wire limiting element is released from the target wire. When the target wire channel is in at least one non-working state, the elastic element is in either a compressed state or a restored state, so that the wire limiting element abuts against the target wire to restrict the upward movement of the target wire in the target wire channel. Alternatively, when the target wire in the target wire channel is clamped and thus in a working state, the magnetic element is in either a released state or an attracted state, so that the wire limiting element is released from the target wire. When the target wire channel is in at least one non-working state, the magnetic element is in either a released state or an attracted state, so that the wire limiting element abuts against the target wire to restrict the upward movement of the target wire in the target wire channel. The wire limiting mechanism is disposed in the mounting body. When the target wire in the target wire channel is clamped and thus in a working state, the elastic element is in either a compressed state or a restored state, so that the wire limiting element is released from the target wire. When the target wire channel is in at least one non-working state, the elastic element is in either a compressed state or a restored state, so that the wire limiting element abuts against the target wire to restrict the upward movement of the target wire in the target wire channel. Alternatively, when the target wire in the target wire channel is clamped and thus in a working state, the magnetic element is in either a released state or an attracted state, so that the wire limiting element is released from the target wire. When the target wire channel is in at least one non-working state, the magnetic element is in either a released state or an attracted state, so that the wire limiting element abuts against the target wire to restrict the upward movement of the target wire in the target wire channel. When the target wire channel is the first wire channel, the target wire is the first wire, and the target swing mechanism is the first swing mechanism; When the target wire channel is the second wire channel, the target wire is the second wire, and the target swing mechanism is the second swing mechanism.

14. The additive printing tool head according to claim 13, wherein: The wire limiting mechanism includes an elastic element and a wire limiting element, and the wire limiting element and the elastic element are connected by transmission or fixed connection; The wire limiting mechanism is set on the target swing mechanism or the mounting body. One end of the elastic element abuts against the target swing mechanism or the mounting body, and the other end of the elastic element is connected to the wire limiting element. When the target wire in the target wire channel is clamped and thus in the working state, the elastic element or the wire limiting element is abutted by the target swing mechanism or the mounting body, so that the elastic element is in either the compressed state or the restored state, so that the wire limiting element is released from the target wire. When the target wire channel is in at least one non-working position, the elastic element or wire limiting element disengages from the target swing mechanism or mounting body, so that the elastic element is in either a compressed state or a restored state, and the wire limiting element abuts against the target wire to restrict the upward movement of the target wire within the target wire channel.

15. The additive printing tool head according to claim 13, wherein: The wire limiting mechanism includes a magnetic component and a wire limiting component, wherein the wire limiting component and the magnetic component are connected by transmission or fixed connection; The wire limiting mechanism is set on the target swing mechanism or the mounting body. When the target wire in the target wire channel is clamped and thus in working state, the magnetic component is in one of the repulsive, natural, or adsorption states, or the wire limiting component is abutted by the target swing mechanism or the mounting body, so that the wire limiting component is released from the target wire. When the target wire channel is in at least one non-working position, the magnetic component is in a repulsive or natural state and an adsorption state, or the wire limiting component is disengaged from the target swing mechanism or the mounting body, so that the wire limiting component abuts against the target wire to restrict the upward movement of the target wire in the target wire channel.

16. The additive printing tool head according to claim 2, wherein, The switching mechanism includes a first pressure roller disposed on the first swing mechanism and a second pressure roller disposed on the second swing mechanism. When the target pressure roller and the extrusion roller approach each other, the target wire is clamped and thus in working state. When the target pressure roller and the extrusion roller move away from each other, the extrusion mechanism releases the clamping of the target wire. When the target wire is the first wire, the target pressure roller is the first pressure roller. When the target wire is the second wire, the target pressure roller is the second pressure roller.

17. The additive printing toolhead according to claim 16, wherein, When the first pressure roller and the extrusion roller are close together and the first wire is clamped and thus in working condition, the second pressure roller and the extrusion roller move away from each other so that the extrusion mechanism releases the clamping of the second wire; when the second pressure roller and the extrusion roller are close together and the second wire is clamped and thus in working condition, the first pressure roller and the extrusion roller move away from each other so that the extrusion mechanism releases the clamping of the first wire.

18. The additive printing tool head according to claim 6, wherein, The first swing mechanism (406) includes a first switching part (411), a first hinge part (412), a first pressure roller (413) and a first swing pivot part (414) arranged sequentially from top to bottom; the second swing mechanism (407) includes a second switching part (421), a second hinge part (422), a second pressure roller (423) and a second swing pivot part (424) arranged sequentially from top to bottom; one end of the elastic element (408) is connected to the first hinge part (412) and the other end is connected to the second hinge part (422).

19. The additive printing toolhead according to claim 18, wherein, The switching mechanism (4) also includes a switching motor (401), a switching motor reduction mechanism (402), a first transmission gear (403), a second transmission gear (404), a switching cam (405), and an elastic element (408); the first transmission gear (403), the second transmission gear (404), the first swing mechanism (406), the second swing mechanism (407), and the elastic element (408) are all mounted on the mounting body; the first transmission gear (403) and the second transmission gear (404) are meshed and connected, and the second transmission gear (404) drives the switching cam (405) to swing; the switching cam (405) is centrally located on the mounting body and above the first reduction gear (304); the first swing mechanism (406) and the second swing mechanism (407) are symmetrically arranged on both sides of the switching cam (405).

20. The additive printing tool head according to claim 4, wherein: The switching mechanism and the extrusion mechanism work together to allow the first wire in the first wire channel and the second wire in the second wire channel to work alternately; it also includes a first cover, which is disposed on the mounting body; the first cover is provided with a first limiting member and a second limiting member; when the first wire channel is in at least one non-working position, the first limiting member cooperates with the first wire limiting mechanism to restrict the upward movement of the first wire in the first wire channel; when the second wire channel is in at least one non-working position, the second limiting member cooperates with the second wire limiting mechanism to restrict the upward movement of the second wire in the second wire channel.

21. An additive printer that uses an additive printing tool head as described in any one of claims 1-20.

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