Cutting device and 3D printing head

Abstract

The application discloses a cutting device and a 3D printing head. The cutting device is used for cutting a continuous filament material which is configured to be transmitted along an axial direction. The cutting device comprises a cutting knife which can rotate around a rotating axis. The rotating axis is fixedly arranged relative to the axial direction of the continuous filament material. The cutting knife has at least one cutting edge. The position of the cutting edge gradually changes relative to the rotating axis along the rotating direction of the cutting knife, so that the distance between the cutting edge rotating to the position corresponding to the axial direction of the continuous filament material and the axial direction of the continuous filament material gradually changes. The 3D printing head comprises a material pipe and the cutting device. The material pipe is used for conveying a cutting object. The material pipe is provided with a gap for exposing the cutting object. The cutting edge rotates with the cutting knife and cuts the cutting object at the gap. Compared with the prior art, the cutting device has the advantages of small cutting torque, simple structure, light weight, high reliability, good dynamic performance or quality and the like.

Description

Technical Field

[0001] This invention belongs to the technical field of 3D printing, and in particular relates to cutting devices and 3D printing heads. Background Technology

[0002] 3D printing constructs objects by printing layer by layer based on digital model files. One such process is Fused Filament Fabrication (FFF) or FDM, where flowable printing material is extruded through nozzles that move along the printing path, stacking layer by layer to form a three-dimensional model. Based on the layer pattern information in the digital model file, the nozzle moves relative to the platform in the XY plane, allowing the nozzle to reach any position within a certain area above the platform. While moving above the platform, the nozzle extrudes printing material at an appropriate speed until one layer is printed. After one layer is completed, the print head and printing platform move away from each other by a certain distance, such as the layer thickness, before printing a new layer, stacking layer by layer until a three-dimensional solid is formed.

[0003] Printing materials are generally fusible thermoplastics, construction slurries, food slurries, or biological slurries, etc. Construction slurries or biopharmaceutical slurries may not require heating. Continuous fiber materials can also be used for printing, enabling 3D printing models of composite materials. For continuous filaments, such as continuous fiber materials, during the printing process, it is often necessary to cut the continuous filaments or fibers in areas where fiber laying is not required, or when changing layers or areas. Traditionally, a cutting blade is used for direct cutting, which requires a large driving force, increasing the power or size of the drive motor. If a scissor-like or linkage-controlled cutting blade is used, the cutting device becomes complex in structure, large in size and weight, resulting in a complex and heavy print head, affecting reliability and printing dynamics or quality. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome at least one of the defects of existing cutting devices, such as large cutting torque, complex structure and large mass, and impact on reliability and printing dynamics or quality, and to provide a cutting device and 3D printing head.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] A first aspect of the present invention provides a cutting apparatus for cutting continuous filaments configured to be conveyed along their axial direction, characterized in that the cutting apparatus includes a cutting blade rotatable about a rotation axis, the positional relationship between the rotation axis and the axis of the continuous filaments being fixed, the cutting blade having at least one cutting edge, the position of the cutting edge gradually changing relative to the rotation axis along the rotation direction of the cutting blade, such that the distance from the cutting edge to the axis of the continuous filaments at a position corresponding to the axis of the continuous filaments gradually changes.

[0007] In this technical solution, a rotating cutting blade is used to cut continuous filaments. During operation, only the direction or angle of rotation needs to be controlled to achieve cutting and resetting of the cutting blade. The structure is simple and easy to control. The position of the cutting edge gradually changes relative to the axis of rotation. When cutting continuous filaments, the cutting edge, as it rotates, glides across the continuous filaments along its extension direction, while the distance between the cutting edge and the axis of the continuous filaments also gradually changes, thus cutting into the continuous filaments. This process ensures that the cutting edge has a certain cutting stroke relative to the continuous filaments, reducing the cutting torque, improving the reliability of the cutting operation, and enabling more efficient cutting of continuous filaments. Furthermore, this cutting method is less likely to cause deformation of the continuous filaments due to excessive force during cutting, which is very beneficial for maintaining the shape of the continuous filaments, making it suitable for cutting both soft and very hard materials. Due to its simple structure, this technical solution reduces the power, torque, size, and weight of the driver (such as a motor or servo) that drives the cutting blade. It is particularly suitable for cutting continuous filament materials in 3D printing based on melt extrusion molding, effectively reducing the size and weight of the 3D print head and improving the dynamic performance and print quality of 3D printing. Furthermore, even if the blade develops some nicks after prolonged use, this will not adversely affect the cutting efficiency. In fact, the nicks create a sawtooth-like cutting effect when the blade cuts through the continuous filament, thereby improving cutting efficiency.

[0008] In this invention, the position or location corresponding to the continuous filament or the axis of the continuous filament refers to the point or area where the cutting edge of the cutting knife is closest to the continuous filament; or the point or area where a plane passing through the axis of the continuous filament and largely coinciding with the rotation axis of the cutting knife intersects with the cutting edge of the cutting knife; or the normal line or normal plane on the cutting edge of the cutting knife at the position or location corresponding to the continuous filament or the axis of the continuous filament intersects with the continuous filament or the axis of the continuous filament.

[0009] In this invention, the axis of the continuous filament refers to the line in the slender continuous filament that is perpendicular to the cross-section and intersects the cross-section. Ideally, it is the line formed along the axial direction of the continuous filament by the center point of the cross-section of the continuous filament; or a line parallel to the length direction in the continuous filament; or the line where the filaments of the continuous filament are located; or a line that can generate the geometry of the connecting filament by moving along the cross-sectional area of ​​the continuous filament.

[0010] Preferably, the cutting edge faces the axis of rotation, or the cutting edge faces a direction away from the axis of rotation; the distance from the cutting edge to the axis of rotation gradually changes along the rotation direction of the cutting blade.

[0011] In this technical solution, the cutting blade is essentially blade-shaped, with the cutting edge generally aligned with the plane of the blade. This effectively utilizes the circumferential length of the cutting blade to ensure the cutting stroke and improve the cutting effect. Furthermore, in this solution, the rotation axis can be easily aligned with the axial direction of the continuous wire feed, facilitating the placement of the cutting blade and saving lateral space. Additionally, the cutting edge of the blade is on a single plane, ensuring cutting quality.

[0012] Preferably, the distance from the position of the blade corresponding to the axis of the continuous filament to the rotation axis varies uniformly with the rotation angle of the cutting blade; and / or, during the rotation of the cutting blade around the rotation axis, the circumferential speed at the position corresponding to the axis of the continuous filament is greater than the rate of change of the distance to the rotation axis.

[0013] In this technical solution, the distance from the position corresponding to the axis of the continuous wire to the rotation axis varies uniformly with the rotation angle of the cutting blade. This ensures that the increase in the blade radius (i.e., the change in distance from the blade to the rotation axis) is the same for every unit angle of rotation of the cutting blade, thus achieving a smoother cutting process. At the position corresponding to the axis of the continuous wire, the movement of the blade has two components: one component is perpendicular to the radius, or in the circumference of the rotation axis, and the other component is along the radius. By making the speed of the blade's movement perpendicular to the radius greater than the speed of position change along the radius, the force is amplified through a lever arm, increasing the cutting force of the cutting blade on the continuous wire and improving cutting efficiency. Alternatively, the feed rate can be reduced, resulting in less force on the continuous wire during the cutting process and better preventing deformation of the continuous wire.

[0014] Preferably, the blade shape is a segment of a gradient curve.

[0015] Further preferred:

[0016] The blade is shaped like a segment of an involute.

[0017] Preferably, the center of the base circle of the involute is located on the axis of rotation.

[0018] Alternatively, the blade may be a segment of a planar helix. Preferably, the starting point of the planar helix is ​​located on the axis of rotation.

[0019] Alternatively, the blade may be circular or arc-shaped, and the center of the circle or arc may be located outside the axis of rotation.

[0020] Preferably, the blade is on a plane.

[0021] In this technical solution, the blade edge gradually changes shape, ensuring smooth cutting. Different blade shapes can meet various cutting requirements. When the blade edge is circular (an eccentric circle relative to the axis of rotation), processing is easier and the cutting tool cost is lower.

[0022] Preferably, the cutting tool has a cutting edge for cutting one continuous filament or multiple continuous filaments simultaneously. Preferably, multiple continuous filaments are arranged sequentially along the extension direction of the cutting edge, and the multiple continuous filaments are equidistant from the normal distance of the cutting edge.

[0023] In this technical solution, multiple continuous filaments can be cut simultaneously using a single blade, allowing them to be severed at the same time despite their different positions. The solution is compact, reliable, and highly efficient.

[0024] Preferably, the cutting tool has two cutting edges, each used for cutting two different continuous filaments:

[0025] When both cutting edges are facing the axis of rotation, or when both cutting edges are facing away from the axis of rotation, the distances of the two cutting edges from the axis of rotation change in opposite directions along the rotation direction of the cutting blade. Preferably, the two cutting edges are linearly symmetrical about a radial direction relative to the rotation of the cutting blade. More preferably, the two continuous filaments are respectively positioned at positions corresponding to the cutting edges that are closer to the axis of rotation.

[0026] Preferably, the cutting tool has two cutting edges, each used for cutting two different continuous filaments:

[0027] When the two cutting edges are respectively facing the direction of rotation and away from the rotation axis, the distances of the two cutting edges to the rotation axis change in the same trend along the rotation direction of the cutting blade. Preferably, the shapes of the two cutting edges are equidistant lines. More preferably, the rays passing through the two continuous filaments pass through the rotation axis, and / or the two continuous filaments are positioned at the midpoint of the two cutting edges, which are equidistant lines, along their extension or rotation direction.

[0028] In this technical solution, by cleverly setting two cutting edges on a single cutting blade, the requirement for independent cutting of two objects at different positions can be met simply by controlling the rotation of the cutting blade. The structure is compact, reliable, fast-responding, and easy to arrange.

[0029] Preferably, the rotation axis is parallel to the axis of the continuous filament, or is set at an angle within ±45°.

[0030] In this technical solution, the axis of rotation is preferably roughly parallel to the axis of the continuous filament. The cutting effect is best when the axis of rotation is parallel to the axis of the continuous filament. Cutting the continuous filament can also be achieved well when the axis of rotation and the axis of the continuous filament are at a certain angle, for example, within ±45°.

[0031] Preferably, the blade faces the axial direction of the rotation axis, and the distance from the blade to the rotation axis is equal along the rotation direction of the cutting blade, and the position of the blade gradually changes in the axial direction of the rotation axis.

[0032] In this technical solution, the cutting blade has a ring structure. The ring-shaped cutting blade is equivalent to "curling" the blade-type cutting blade, which can greatly reduce the volume of the cutting blade. It also allows the rotation axis of the cutting blade to be set approximately perpendicular to or at an angle to the axis of the continuous filament. This facilitates placing the driver away from the continuous filament (i.e., away from the feed tube used to transport the continuous filament), avoiding interference between the driver and the feed tube. It also allows the cutting blade to approach and penetrate into the gaps or notches of the feed tube for cutting, which helps to reduce the rotation radius of the cutting blade and thus increases the cutting torque of the cutting blade.

[0033] Preferably, during the rotation of the cutting blade around the rotation axis, the circumferential speed of the blade at the position corresponding to the axis of the continuous filament is greater than the speed of change along the axial direction of the rotation axis.

[0034] In this technical solution, at the position corresponding to the continuous filament, the movement of the cutting edge has two components: one component is along the axial direction of the rotation axis, and the other component is perpendicular to the rotation axis, which is along the circumference around the rotation axis. By making the speed of the cutting edge perpendicular to the rotation axis greater than the speed of change along the axial direction of the rotation axis, it is equivalent to amplifying the force through a lever arm, which can increase the cutting force of the cutting blade on the continuous filament and improve cutting efficiency. Alternatively, the cutting feed speed can be reduced, resulting in less force on the continuous filament during the cutting process, and better preventing deformation of the continuous filament during cutting.

[0035] Preferably, the blade is a segment of a cylindrical helix, or the blade is a segment of the edge of a cylindrical oblique section.

[0036] Preferably, the curve containing the cutting edge is located on a ring surface.

[0037] In this technical solution, a suitable blade shape can be selected according to different cutting requirements. The machining of the blade shapes for both structures is relatively simple.

[0038] Preferably, the cutting edge is located on the side of the cutting blade closer to the axis of rotation, or the cutting edge is located on the side of the cutting blade away from the axis of rotation.

[0039] In this technical solution, the shape of the cutting edge can be reasonably selected according to the relative position of the cutting edge and the cutting point to achieve a better cutting effect.

[0040] Preferably, the cutting tool has two cutting edges, each used for cutting two continuous filaments:

[0041] When the two cutting edges face the same direction along the axis of rotation, their positions change in opposite directions along the axis of rotation. Preferably, the two cutting edges are symmetrical with respect to a plane passing through the axis of rotation. More preferably, the two continuous filaments are respectively positioned at positions corresponding to the cutting edges extending shorter along the axis of rotation in their oriented direction.

[0042] Preferably, the cutting tool has two cutting edges, each used for cutting two continuous filaments:

[0043] When the two cutting edges face opposite directions of the rotation axis, the positions of the two cutting edges change in the same trend along the rotation axis along the direction of rotation of the cutting blade. Preferably, the two cutting edges have the same shape, and the distance between the two cutting edges along the axial direction of the rotation axis is equal everywhere. More preferably, the two continuous filaments are arranged sequentially along the axial direction of the rotation axis.

[0044] In this technical solution, by cleverly setting two cutting edges on a single cutting blade, the requirement for independent cutting of two objects at different positions can be met simply by controlling the rotation of the cutting blade. The structure is compact, reliable, fast-responding, and easy to arrange.

[0045] Preferably, the rotation axis is perpendicular to the axis of the continuous filament or is set at an angle within the range of 45°-135°.

[0046] In this technical solution, when using a ring-shaped cutting blade, the rotation axis is preferably approximately perpendicular to the axis of the continuous filament. A good cutting effect is achieved when the angle between the rotation axis and the axis of the continuous filament is within the range of 45°-135°. The best cutting effect is achieved when the rotation axis is perpendicular to the axis of the continuous filament.

[0047] Preferably, the cutting edge is a smooth, continuous cutting edge or a serrated cutting edge. Preferably, the serration height of the serrated cutting edge is less than the diameter of the continuous filament, and / or, the envelope formed at the top or tip of the serration is a segment of a gradient curve. Preferably, the gradient curve includes an involute, a spiral, or an eccentric circle.

[0048] In this technical solution, the cutting edge can be a smooth, continuous cutting edge. Alternatively, the cutting edge can have a structure with minute serrations, i.e., a serrated cutting edge, which can achieve faster cutting, a cleaner cutting surface, or lower cutting force.

[0049] Preferably, the cutting device further includes a driver having a rotatable output shaft connected to the cutting blade to drive the cutting blade to rotate. Preferably, the driver includes a servo motor, a stepper motor, or a servo motor. Preferably, the cutting blade has a shaft hole for fitting onto the output shaft of the driver.

[0050] In this technical solution, a servo, also known as a servo motor, is an actuator that uses a combination of a miniature motor and a reduction gear system to rotate or oscillate the output shaft at a limited angle. It may also include a control board. Generally, it can precisely control the rotation angle and determine the starting zero point. It is typically controlled by a PWM (pulse width modulation) signal. For example, the internally integrated control board can be used to control the rotation angle of the output shaft, enabling oscillation of positive and negative angles or multi-turn rotation within a certain range. For instance, when a certain frequency or pulse width is reached, the output shaft returns to zero. When the frequency or pulse width increases, the output shaft rotates in one direction, and when the frequency or pulse width decreases, the output shaft rotates in the other direction. It is commonly used in rudder drives in drones or steering drives in remote-controlled cars. It is lightweight, small in size, and has high torque, or significantly reduces the size and weight of the actuator for the same torque.

[0051] A second aspect of the present invention provides a 3D printing head, including a feed tube and the cutting device, wherein the feed tube is used to transport the continuous filament, the feed tube is provided with a notch for exposing the continuous filament, and the cutting blade rotates with the cutting blade and cuts the continuous filament at the notch.

[0052] In this technical solution, a rotating cutting blade is used to cut continuous filaments. During operation, only the direction or angle of rotation needs to be controlled to achieve cutting and resetting of the cutting blade. The structure is simple and easy to control. The position of the cutting edge gradually changes relative to the axis of rotation. When cutting continuous filaments, the cutting edge, as it rotates, glides across the continuous filaments along its extension direction, while the distance between the cutting edge and the axis of the continuous filaments also gradually changes, thus cutting into the continuous filaments. This process ensures that the cutting edge has a certain cutting stroke relative to the continuous filaments, reducing the cutting torque, improving the reliability of the cutting operation, and enabling more efficient cutting of continuous filaments. Furthermore, this cutting method is less likely to cause deformation of the continuous filaments due to excessive force during cutting, which is very beneficial for maintaining the shape of the continuous filaments, making it suitable for cutting both soft and very hard materials. Due to its simple structure, this technical solution reduces the power, torque, size, and weight of the driver (such as a motor or servo) that drives the cutting blade. It is particularly suitable for cutting continuous filament materials in 3D printing based on melt extrusion molding, effectively reducing the size and weight of the 3D print head and improving the dynamic performance and print quality of 3D printing. Furthermore, even if the blade develops some nicks after prolonged use, this will not adversely affect the cutting efficiency. In fact, the nicks create a sawtooth-like cutting effect when the blade cuts through the continuous filament, thereby improving cutting efficiency.

[0053] Preferably:

[0054] The feed tube includes a first feed tube and a second feed tube, which are arranged coaxially and have a gap between them. The gap forms the notch, and the continuous filament is conveyed from the first feed tube to the second feed tube.

[0055] Alternatively, the side wall of the feed tube is provided with a notch to expose the continuous filament at the notch, and the notch forms the gap;

[0056] Alternatively, one end of the feed tube is provided with a nozzle, the extrusion port of which is used for material discharge from the 3D printing head, and the extrusion port forms the notch. Preferably, the cutting blade has a stepped structure between the cutting edge and the position where the rotation axis passes through the cutting blade, so that the position where the rotation axis passes through the cutting blade is away from the extrusion port.

[0057] Preferably, when the cutting edge is facing the axis of rotation or the cutting edge is facing away from the axis of rotation; and the distance from the cutting edge to the axis of rotation gradually changes along the rotation direction of the cutting blade:

[0058] The material tube has a first material tube end face at one end of the notch, and the cutting edge is located on the edge of the cutting blade facing the first material tube, and the first material tube end face is flat; or, the material tube has a second material tube end face at the other end of the notch, and the cutting edge is located on the edge of the cutting blade facing the second material tube, and the second material tube end face is flat.

[0059] Preferably, when the blade is oriented in the axial direction of the rotation axis, the distance from the blade to the rotation axis is equal along the rotation direction of the cutting blade, and the position of the blade gradually changes in the axial direction of the rotation axis:

[0060] The feed tube has a first feed tube end face at one end of the notch. The first feed tube end face faces the side of the cutting blade that is close to the axis of rotation in the radial direction of its rotation. The first feed tube end face is a cylindrical or spherical surface that matches the cutting blade.

[0061] Alternatively, the feed tube has a first feed tube end face at one end of the notch, the first feed tube end face facing the side of the cutting blade away from the axis of rotation in the radial direction of its rotation, and the first feed tube end face is a cylindrical or spherical surface that matches the cutting blade.

[0062] Alternatively, the feed tube has a second feed tube end face at the other end of the notch, the second feed tube end face facing the side of the cutting blade away from the axis of rotation in the radial direction of its rotation, and the second feed tube end face is a cylindrical or spherical surface that matches the cutting blade;

[0063] Alternatively, the feed tube has a second feed tube end face at the other end of the notch, the second feed tube end face facing the side of the cutting blade close to the axis of rotation in the radial direction of its rotation, and the second feed tube end face is a cylindrical or spherical surface that matches the cutting blade.

[0064] Preferably, the feed tube is provided with a cutting ring at the notch, the sidewall of the cutting ring is provided with an inlet hole or an outlet hole corresponding to the feed tube, the cutting blade is disposed in the cutting ring and is rotatably clearance-fitted with the cutting ring, the inner side of the cutting ring at the inlet hole or the outlet hole forms the first feed tube end face, or the inner side of the cutting ring at the inlet hole or the outlet hole forms the second feed tube end face.

[0065] Preferably, two pipes are provided inside the material pipe; or two material pipes are provided, each of which is provided with one pipe.

[0066] Preferably, the feed tube includes a feed tube section and a bend, the pipe inside the bend is a bend, the pipe in the vertical part of the bend is coaxial with the pipe inside the feed tube section, the bend and the feed tube section have a gap, and the cutting blade can penetrate into the gap between the bend and the feed tube section to cut the continuous fiber material conveyed from the feed tube section to the bend.

[0067] Preferably, it further includes a printhead, a nozzle seat ring, and a driver. The nozzle seat ring is rotatably connected to the printhead via a bearing. The driver and the feed tube are fixedly connected to the nozzle seat ring. The bent tube is inserted into the heating block, and the heating block is fixedly connected to the nozzle seat ring via a second pin. The driver drives the cutting blade to rotate. When the cutting blade rotates, the distance by which the cutting blade extends into the gap between the bent tube and the feed tube changes.

[0068] Preferably, a chamfer is provided at the upper end of the bend to guide the continuous filament material in.

[0069] Preferably, it further includes an inclined nozzle section, the inclined nozzle section having a through hole, and the pipe of the inclined portion of the bend is coaxial with the through hole in the inclined nozzle section.

[0070] Preferably, it further includes a first extrusion port and a second extrusion port, the second extrusion port being disposed on the inclined nozzle portion, the inclined nozzle portion being in an inclined state and inclined toward the direction of the first extrusion port.

[0071] This technical solution can adapt to the cutting of continuous wire under different conditions, has a wide range of applications, and is flexible in use. The matching of the material tube end face with the cutting blade can improve the cutting quality.

[0072] The positive and progressive effects of this invention are as follows:

[0073] In this technical solution, a rotating cutting blade is used to cut continuous filaments. During operation, only the direction or angle of rotation needs to be controlled to achieve cutting and resetting of the cutting blade. The structure is simple and easy to control. The position of the cutting edge gradually changes relative to the axis of rotation. When cutting continuous filaments, the cutting edge, as it rotates, glides across the continuous filaments along its extension direction, while the distance between the cutting edge and the axis of the continuous filaments also gradually changes, thus cutting into the continuous filaments. This process ensures that the cutting edge has a certain cutting stroke relative to the continuous filaments, reducing the cutting torque, improving the reliability of the cutting operation, and enabling more efficient cutting of continuous filaments. Furthermore, this cutting method is less likely to cause deformation of the continuous filaments due to excessive force during cutting, which is very beneficial for maintaining the shape of the continuous filaments, making it suitable for cutting both soft and very hard materials. Due to its simple structure, this technology reduces the power, torque, size, and weight of the driver (such as a motor or servo) that drives the cutting blade. This solution is particularly suitable for cutting continuous filamentary materials, such as continuous fiber materials, in 3D printing based on melt extrusion molding. It effectively reduces the size and weight of the 3D print head, improving the dynamic performance and print quality of 3D printing. Furthermore, even if the cutting edge develops some nicks after prolonged use, this will not adversely affect the cutting efficiency. In fact, the nicks create a sawtooth-like cutting effect when the blade cuts through the continuous filament, thereby improving cutting efficiency. Attached Figure Description

[0074] Figure 1a This is a front view schematic diagram of a cutting device for a blade-type cutting knife according to the present invention;

[0075] Figure 1b for Figure 1a A three-dimensional schematic diagram of the cutting device;

[0076] Figure 2a and Figure 2b for Figure 1a or Figure 1b A bottom view of the cutting device, in which... Figure 2a This is for continuous filament feeding. Figure 2b This refers to the cutting state of continuous filaments;

[0077] Figure 3a This is a schematic diagram of the specific structure of a cutting blade according to the present invention;

[0078] Figure 3b This is a schematic diagram of the blade curve of a cutting knife according to the present invention;

[0079] Figure 4 This is a schematic diagram of a cutting blade with double inner and outer blades according to the present invention;

[0080] Figure 5a The diagram shows a symmetrical double-bladed cutting knife of the present invention, where the blade radius is smallest at the symmetrical point.

[0081] Figure 5b This is a schematic diagram of another symmetrical double-bladed cutting blade of the present invention, where the blade radius is largest at the symmetrical point;

[0082] Figure 6a This is a schematic diagram of a cutting blade with an eccentric circular blade according to the present invention;

[0083] Figure 6b This is a schematic diagram of a serrated cutting blade according to the present invention;

[0084] Figure 7a This is a cross-sectional schematic diagram of a 3D printing head equipped with a cutting device according to the present invention;

[0085] Figure 7b for Figure 7a A partial cross-sectional view of the cutting device area of ​​the 3D printing head;

[0086] Figure 7c for Figure 7a A magnified view of a portion of the cutting blade area of ​​a 3D printing head;

[0087] Figure 7d This is a partial cross-sectional schematic diagram of the extrusion port of the 3D printing head where the blade of the present invention is located;

[0088] Figure 8a and Figure 8b for Figure 7a or Figure 7b A bottom-view diagram. Figure 8a In continuous filament conveying mode, Figure 8b In the cutting state;

[0089] Figure 9a and Figure 9b This is a three-dimensional schematic diagram of a cutting device for a ring-shaped (tubular) cutting blade according to the present invention. Figure 9c and Figure 9d This is a side view of the cutting device for a ring-shaped (tubular) cutting blade. Figure 9a and Figure 9c This is a continuous filament feeding state. Figure 9b and Figure 9d In the cutting state;

[0090] Figure 10a and Figure 10b This is a schematic diagram of a beveled ring-shaped cutting blade according to the present invention. Figure 10a This is a 3D schematic diagram. Figure 10b This is a side view;

[0091] Figure 11a and Figure 11b This is a schematic diagram of a ring-shaped cutting blade with a spiral blade according to the present invention. Figure 11a This is a schematic diagram of the inner cutting edge of the ring. Figure 11b A schematic diagram of the outer edge of the ring;

[0092] Figure 12a and Figure 12b This is a three-dimensional schematic diagram of a cutting device for cutting the outer side of a ring-shaped (tubular) cutting blade according to the present invention. Figure 12c and Figure 12d This is a side view. Figure 12a and Figure 12c This is a continuous filament feeding state. Figure 12b and Figure 12d In the cutting state;

[0093] Figure 12e A schematic diagram showing a cutting ring installed on the outside of the cutting blade;

[0094] Figure 13a and Figure 13b This is a schematic diagram of a cutting blade with two adjacent cutting edges along the rotation axis of the cutting blade according to the present invention;

[0095] Figure 14a and Figure 14b This invention employs... Figure 13a and Figure 13b A schematic diagram of the cutting device for the cutting blade shown;

[0096] Figure 15a This is a schematic diagram of a symmetrical double-blade cutting device of the present invention, where the blade extends the longest at the symmetrical point;

[0097] Figure 15b for Figure 15a A schematic diagram of a symmetrical double-edged cutting blade, with the blade extending the longest at the symmetrical point;

[0098] Figure 16a This is a schematic diagram of another double-symmetrical double-blade cutting device of the present invention, where the blades extend the shortest at the symmetrical point;

[0099] Figure 16b for Figure 16a A schematic diagram of a symmetrical double-bladed cutting blade, with the blade extending the shortest distance at the symmetrical point;

[0100] Figure 17 This is a partial cross-sectional view of the annular cutting blade of the present invention located at the extrusion port of the 3D printing head. Detailed Implementation

[0101] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0102] A cutting apparatus is provided for cutting a continuous filament 20, the continuous filament 20 being configured to be conveyed along its axial direction. The cutting apparatus includes a cutting blade 131 rotatable about a rotation axis 99, the rotation axis 99 having a fixed positional relationship with the axis of the continuous filament 20. The cutting blade 131 has at least one cutting edge 1311, the position of which gradually changes relative to the rotation axis 99 along the rotation direction of the cutting blade 131, such that the distance from the cutting edge 1311 to the axis of the continuous filament 20 at a position corresponding to the axis of the continuous filament 20 gradually changes. Preferably, the continuous filament comprises a continuous linear material or wire, such as continuous fiber filament, metal wire, or optical fiber.

[0103] In this technical solution, the continuous filament 20 is cut by rotating the cutting blade 131. During operation, only the direction or angle of rotation needs to be controlled to achieve cutting and resetting of the cutting blade 131. The structure is simple and easy to control. The position of the blade 1311 gradually changes relative to the axis of rotation. When cutting the continuous filament 20, as the cutting blade 131 rotates, it passes through the continuous filament 20 along the extension direction of the blade 1311. At the same time, the distance between the blade 1311 and the axis of the continuous filament 20 also gradually changes, thus cutting into the continuous filament 20. This process ensures that the blade 1311 has a certain cutting stroke relative to the continuous filament 20, which reduces the cutting torque, improves the reliability of the cutting operation, and enables more efficient cutting of the continuous filament 20. In addition, this cutting method is less likely to cause deformation of the continuous filament 20 due to excessive force during the cutting process, which is very beneficial to maintaining the shape of the continuous filament 20, making it suitable for cutting materials that are relatively soft or very hard. Due to its simple structure, this technical solution reduces the power, torque, size, or weight of the driver (such as a motor or servo) that drives the cutting blade 131. It is particularly suitable for cutting continuous filament materials in 3D printing based on melt extrusion molding, effectively reducing the size and weight of the 3D print head and improving the dynamic performance and print quality of 3D printing. Furthermore, even if the blade 1311 develops a certain nick after prolonged use, it will not adversely affect the cutting efficiency. In fact, the nick creates a sawtooth-like cutting effect when the blade 1311 cuts through the continuous filament 20, thereby improving cutting efficiency.

[0104] The following cutting device embodiments 1-5 provide a cutting device with a blade-type structure for the cutting blade. Further, the cutting edge 1311 of the cutting device faces the rotation axis 99, or the cutting edge 1311 faces a direction away from the rotation axis 99; along the rotation direction of the cutting blade 131, the distance from the cutting edge 1311 to the rotation axis 99 gradually changes.

[0105] For the blade-type cutting blade 131, the cutting blade 131 is basically blade-shaped, or the curve of the cutting edge 1311 of the cutting blade 131 is located on a plane, and the direction of the cutting edge 1311 is generally along the direction of the blade plane of the cutting blade 131. This can effectively utilize the circumferential length of the cutting blade 131 to ensure the cutting stroke and improve the cutting effect. Moreover, the rotation axis 99 can be easily ensured to be generally consistent with the axial direction of the continuous wire 20, making it easy to arrange the cutting blade 131 and saving lateral space. In addition, the cutting edge 1311 of the cutting blade 131 is on a plane, which can ensure the cutting quality.

[0106] Example 1 of the cutting device:

[0107] Figures 1a to 3b This diagram illustrates a cutting device for cutting continuous filament (20 of which can be conveyed by a feed tube 50). A cutting blade 131 is mounted on the output shaft 89 of a driver 80, and the driver 80 can control the output shaft 89 to rotate along its rotation axis 99. Figure 1a The rotation indicated by the arrow θ causes the cutting blade 131 to rotate.

[0108] The cutting blade 131 has a blade-type structure with a cutting edge 1311 at its edge. The distance (i.e., radius) from the cutting edge 1311 to the rotation axis 99 varies with the rotation angle, that is, it gradually changes along the rotation direction of the cutting blade 131. For example, as it rotates clockwise with arrow θ, the radius of the cutting edge 1311 increases. The cutting edge 1311 of the cutting blade 131 faces the rotation axis 99 of the cutting blade 131 or faces a direction away from the rotation axis 99 of the cutting blade 131. As the cutting blade 131 rotates around the rotation axis 99, the distance from the position of the cutting edge 1311 corresponding to the axis of the continuous wire 20 to the rotation axis 99 of the cutting blade 131 gradually changes. Figure 1a , 1b In step 2a, the cutting blade 131 is in a state where the blade 1311 has not yet touched the continuous wire 20, and the continuous wire 20 can be continuously fed downwards, unaffected by the cutting blade. When the cutting blade rotates clockwise along arrow θ, it will rotate to the position shown in the image. Figure 2bAs shown, the larger radius blade 1311 will move to the position of the continuous wire 20 as it rotates. When it rotates to a certain angle, the larger radius blade 1311 will touch the continuous wire 20. With continued rotation, an even larger radius blade 1311 will cut into the continuous wire. As the cutting blade continues to rotate and the larger radius blade continues to cut, the continuous wire 20 can eventually be completely severed. Then, the cutting blade 131 can rotate in the opposite direction (e.g., counterclockwise) back to its original position. Figure 2a In the state shown, the cutting blade avoids the continuous wire 20, which can then be fed back along the feed tube 50. Alternatively, the cutting blade can continue to rotate, such as clockwise, until the rotation returns to the starting position. Figure 2a The state shown avoids the continuous wire material while allowing the blade 1311 to re-approach the continuous wire material, so that the continuous wire material 20 can be fed downwards again, preparing for the next rapid cut.

[0109] In this embodiment, as Figure 3b As shown, the cutting edge 1311 of the cutting blade 131 is a segment of a planar gradient curve 901. The gradient curve can be a planar spiral, an involute, or an arc, etc. More preferably, if the gradient curve is a planar spiral or an involute, the starting point (center point) can be located on the rotation axis 99. Of course, the cutting edge 1311 of the cutting blade 131 can also be of other forms. For example, in other embodiments, the shape of the cutting edge 1311 of the cutting blade 131 can be a segment of an involute, and preferably, the center of the base circle of the involute is located on the rotation axis 99. Alternatively, the shape of the cutting edge 1311 of the cutting blade 131 can also be as follows: Figure 6a The eccentric circular structure (i.e., the center of the circle is offset from the rotation axis 99) is located at the eccentric position of the circular cutting edge 1311. In practical applications, a suitable cutting edge shape can be selected according to different cutting requirements.

[0110] In the various embodiments of this invention, the cutting edge can be a smooth, continuous cutting edge structure, or it can be a structure with tiny serrations, i.e., a serrated cutting edge, such as... Figure 6b As shown, this can achieve faster cutting results, cleaner cut surfaces, or lower cutting forces; optimally, as... Figure 6b The height h of the saw teeth shown can be less than the diameter or radius of the continuous filament 20. The envelope formed at the top of the saw teeth or the tip of the teeth is a gradient curve, which can be an involute, a spiral, or part of an eccentric circle.

[0111] like Figure 3bFurthermore, the distance from the cutting edge 1311 to the rotation axis 99 varies uniformly with the rotation angle of the cutting blade 131 (the distance from the position of the cutting edge 1311 corresponding to the axis of the continuous wire 20 to the rotation axis 99 varies uniformly with the rotation angle of the cutting blade 131). For every unit angle of rotation of the cutting blade 131, the increase in the radius of the cutting edge 1311 is the same, thus achieving a smoother cutting process. Furthermore, during the rotation of the cutting blade 131, at the position corresponding to the continuous wire 20, the circumferential speed of the cutting edge 1311 is greater than the rate of change of the distance from the cutting edge 1311 to the rotation axis 99. At the position corresponding to the axis of the continuous filament 20, the movement of the blade 1311 has two components: one component is perpendicular to the radius, or in the direction of the circumference around the rotation axis 99, and the other component is along the radius. By making the speed of the blade 1311 moving perpendicular to the radius greater than the speed of change along the radius, it is equivalent to amplifying the force through the lever arm. This can increase the cutting force of the cutting blade 131 on the continuous filament 20, improve the cutting efficiency, or reduce the cutting feed speed. The continuous filament is subjected to less force during the cutting process, which can better prevent the continuous filament from deforming during the cutting process.

[0112] exist Figure 3b and Figure 3a As illustrated, a shaft hole 1312 can also be provided on the cutting blade 131 so that it can be fitted onto the output shaft of the driver 80, such as... Figures 1b to 2b The cutting blade 131 can be fixed to the output shaft 89 by screw 68. A spline 1313 can also be provided within the shaft hole 1312 for connection with… Figure 1b The output shaft 89 of the servo shown is fitted with an external spline. It is understood that the connection method between the cutting blade 131 and the output shaft 89 is not limited to the method described in this embodiment; other connection methods, such as key connections or other connection methods, may be used.

[0113] Figure 1b The driver 80 shown in the diagram can be a servo. A servo is an actuator that uses a combination of a miniature motor and a reduction gear system to rotate or oscillate the output shaft at a limited angle. It can generally precisely control the rotation angle and can determine the starting zero point. It is typically controlled by a PWM signal and is commonly used in rudder drives in drones or steering drives in remote-controlled cars. It is lightweight, small in size, and has high torque. Of course, it is understood that in other embodiments, the driver 80 can also be a stepper motor or a servo motor.

[0114] In this embodiment, the continuous filament 20 is further conveyed in a straight line by the feed tube 50, and the axis of the continuous filament 20 or the feed tube 50 is substantially parallel to the rotation axis of the cutting blade.

[0115] Cutting device embodiment 2:

[0116] The cutting device in this embodiment is basically the same as that in embodiment 1, except that the cutting device in this embodiment is used to cut two continuous filaments 20, such as... Figure 3b As shown, two continuous wires 20 are arranged sequentially along the extension direction of the blade 1311, and the two continuous wires 20 are equidistant from the normal distance of the blade 1311.

[0117] Thus, when the cutting blade 131 is used Figure 3b When rotating clockwise (or in the direction of increasing radius), the two continuous wires 20, although in different positions, can be cut simultaneously. This allows for the simultaneous cutting of two continuous wires by a single blade 1311, ensuring that the two continuous wires, despite their different positions, can be cut at the same time. The structure is compact, reliable, and highly efficient. Generally, when feeding continuous wires into the feed tube, the cutting blade 131 can rotate around a rotation axis 99 that is approximately perpendicular to the blade. The distance (radius) from the blade 1311 to the rotation axis 99 increases or decreases with the rotation angle. The axis of the continuous wires 20 (i.e., the axis of the feed tube 50) is approximately parallel to the rotation axis 99 of the cutting blade. When not cutting, the portion with a radius smaller than the distance between the continuous wire 20 and the rotation axis 99 of the cutting blade 131 corresponds to the continuous wire 20. When cutting, the cutting blade 131 is rotated, increasing the radius of the blade 1311 until the portion with a radius larger than the distance between the continuous wire 20 and the rotation axis 99 corresponds to the continuous wire 20, thus achieving cutting. Alternatively, when the blade 1311 of the cutting blade 131 is facing the direction of the rotation axis of the cutting blade, when not cutting, the portion with a radius larger than the distance between the continuous wire 20 and the rotation axis 99 of the cutting blade 131 corresponds to the continuous wire 20. When cutting, the cutting blade 131 is rotated, decreasing the radius of the blade 1311 until the portion with a radius smaller than the distance between the continuous wire 20 and the rotation axis 99 corresponds to the continuous wire 20, thus achieving cutting.

[0118] In other embodiments, more continuous wires 20 can be provided, and these continuous wires 20 need to have equal normal distances from the cutting edge 1311. Of course, the normal distances from two continuous wires to the cutting edge can also be different, so that the cutting order of the two continuous wires can be adjusted accordingly.

[0119] Cutting device embodiment 3:

[0120] The cutting device in this embodiment is basically the same as that in cutting device embodiment 1, except that in this embodiment, the cutting blade 131 has two blades 1311a and 1311b. The two blades 1311a and 1311b are used for cutting two different continuous filaments (first continuous filament 201 and second continuous filament 202), respectively. Furthermore, in this embodiment, the two blades 1311a and 1311b are oriented in a direction away from the rotation axis 99 and in a direction toward the rotation axis 99, respectively. Along the rotation direction of the cutting blade 131, the distances of the two blades 1311a and 1311b from the rotation axis 99 change in the same trend.

[0121] like Figure 4 As shown, for example, cutting edges 1311a and 1311b can be parts of involutes or helices 901a and 901b, respectively, and 901a and 901b can be equidistant curves (offsets). Cutting edges 1311a and 1311b are arranged opposite each other, with cutting edge 1311a facing away from the shaft hole 1312 (or rotation axis 99), and cutting edge 1311b facing the shaft hole 1312 (i.e., rotation axis 99). Furthermore, the connecting line of the first continuous wire 201 and the second continuous wire 202 passes through the shaft hole 1312 (or rotation axis 99), and furthermore, the first continuous wire 201 and the second continuous wire 202 are located at the midpoint of the cutting edge 1311a or 1311b along the extension direction (or rotation direction) of the cutting edge. When the cutting blade 131 rotates clockwise, the radii of both blades 1311a and 1311b increase. The inner blade 1311a will cut the first continuous filament 201, while the outer blade 1311a will move away from the second continuous filament 202, preventing it from being cut. When the cutting blade 131 rotates counterclockwise, the radii of both blades 1311a and 1311b decrease. The inner blade 1311a will move away from the first continuous filament 201, preventing it from being cut, while the outer blade 1311a will cut the second continuous filament 202. Thus, a single cutting blade can achieve independent cutting control of two continuous filaments (the first continuous filament 201 and the second continuous filament 202).

[0122] In this embodiment, two pipes can be provided in the material pipe 50 for conveying the filaments 201 and 202, or there can be two material pipes 50, each of which is provided with a feeding pipe. These two pipes convey the continuous filaments 201 and 202 respectively.

[0123] Cutting device embodiment 4:

[0124] This embodiment is basically the same as the cutting device embodiment 1, except that in this embodiment, the cutting blade 131 has two blades 1311a and 1311b. The two blades 1311a and 1311b are used for cutting two different continuous filaments (the first continuous filament 201 and the second continuous filament 202), respectively. Furthermore, in this embodiment, both blades are oriented away from the rotation axis 99. Along the rotation direction of the cutting blade 131, the distances of the two blades 1311a and 1311b from the rotation axis 99 change in opposite directions.

[0125] In this embodiment, Figure 5a The two blades 1311a and 1311b, which face outward (towards the direction away from the axis of rotation 99), can be arranged symmetrically above and below each other in the figure. Figure 5a The cutting edge at the symmetrical point is closest to the shaft hole 1312, allowing the first continuous wire 201 and the second continuous wire 202 to be positioned relatively symmetrically close to the symmetrical point. In this configuration, the first continuous wire 201 and the second continuous wire 202 are respectively positioned close to the rotation axis 99 corresponding to the two cutting edges 1311a and 1311b. Thus, when the cutting blade rotates clockwise, the radius of the cutting edge 1311b corresponding to the second continuous wire 202 increases, allowing it to cut the second continuous wire 202, while the radius of the cutting edge 1311a corresponding to the first continuous wire 201 decreases, preventing it from cutting the first continuous wire 201. If the cutting blade continues to rotate clockwise, the cutting edge 1311b can further cut the first continuous wire 201. When the cutting blade rotates counterclockwise, the radius of the blade 1311a corresponding to the first continuous filament 201 increases, allowing it to cut the first continuous filament 201. Conversely, the radius of the blade 1311b corresponding to the second continuous filament 202 decreases, preventing it from cutting the second continuous filament 202. If the cutting blade continues to rotate counterclockwise, the blade 1311b can further cut the first continuous filament 201.

[0126] Cutting device embodiment 5:

[0127] The cutting device in this embodiment is basically the same as that in cutting device embodiment 4, except that, in this embodiment, as... Figure 5bAs shown, the two outward-facing cutting edges 1311a and 1311b can be symmetrically arranged vertically relative to the diagram. The cutting edge at the symmetrical point is furthest from the shaft hole 1312, allowing the first continuous wire 201 and the second continuous wire 202 to also be symmetrically arranged vertically, separated from the symmetrical point. At this time, the first continuous wire 201 and the second continuous wire 202 are respectively positioned at positions corresponding to the two cutting edges 1311a and 1311b that are closer to the rotation axis 99. Thus, when the cutting blade rotates clockwise, the radius of the cutting edge 1311a corresponding to the first continuous wire 201 increases and can cut the second continuous wire 202, while the radius of the cutting edge 1311b corresponding to the second continuous wire 202 decreases and does not cut the second continuous wire 202. When the cutting blade rotates counterclockwise, the radius of the blade 1311b at the position corresponding to the second continuous filament 202 increases, allowing it to cut the second continuous filament 202. The radius of the blade 1311a at the position corresponding to the first continuous filament 201 decreases, preventing it from cutting the first continuous filament 201.

[0128] The following cutting apparatus embodiments 6-9 provide a cutting apparatus in which the cutting blade 131 has a ring-shaped structure. Further, the cutting edge 1311 faces the axial direction of the rotation axis 99. Along the rotation direction of the cutting blade 131, the distance from the cutting edge 1311 to the rotation axis is equal, and the position of the cutting edge 1311 gradually changes in the axial direction of the rotation axis. The so-called ring-shaped cutting blade 131 can be a ring or a tube, or it can be part of a ring or a tube. The cutting edge can be located on the annular surface of the ring or tube, or the curve containing the cutting edge of the cutting blade can be located on the annular surface.

[0129] The annular cutting blade is essentially formed by "curling" a blade-type cutting blade, which greatly reduces the volume of the cutting blade 131. It also allows the rotation axis 99 of the cutting blade 131 to be set approximately perpendicular to or at an angle to the axis of the continuous filament 20. This facilitates setting the driver 80 away from the continuous filament 20 (i.e., away from the feed tube 50 used to transport the continuous filament 20), avoiding interference between the driver 80 and the feed tube 50. It also allows the cutting blade 131 to approach and penetrate into the gaps or notches of the feed tube 50 for cutting, which helps to reduce the rotation radius of the cutting blade 131 and thus increases the cutting torque of the cutting blade 131.

[0130] Cutting device embodiment 6:

[0131] The parts of the cutting device in this embodiment that are the same as those in cutting device embodiment 1 will not be described again. The differences are as follows: Figures 9a to 10b As shown, the cutting blade has a ring-shaped structure, and the cutting blade 131 is as follows. Figure 10aThe diagram illustrates a ring-shaped blade structure, with the cutting edge 1311 at the tip of the ring blade, and a shaft hole 1312 at the root. The distance from the cutting edge 1311 to the root of the blade along the axial direction of this ring blade varies with the rotation angle (i.e., the position of the cutting edge 1311 gradually changes towards one end in the axial direction of the rotation axis 99), for example, optimally increasing, or the cutting edge 1311 of the cutting blade 131 faces the axial direction of the rotation axis 99 of the cutting blade 131. Along the rotation direction of the cutting blade 131, the distance from the cutting edge 1311 to the rotation axis 99 is equal. As the cutting blade 131 rotates, the position of the cutting edge 1311 corresponding to the axis of the continuous filament 20 gradually changes in the axial direction of the rotation axis 99. In this embodiment, for example... Figure 10b As shown, the lateral projection of the blade 1311 can be a diagonal line (i.e., the shape of the blade 1311 is a segment of the edge of a cylindrical bevel). Of course, the blade 1311 of the cutting tool 131 can also be in other forms, such as in other embodiments, like... Figure 11a and 11b As shown, the blade shape can be a segment (part) of a cylindrical helix 902.

[0132] In this embodiment, the cutting edge 1311 can be located on the inner side of the annular curved blade (e.g., Figure 10a and Figure 11a As shown), the blade 1311 is located on the side of the cutting blade 131 near the rotation axis 99. In this example... Figures 9a to 9d The embodiments in the examples may employ a cutting blade structure with an inner blade edge, such as the embodiments shown in 10a and 11a.

[0133] Furthermore, during the rotation of the cutting blade 131, the circumferential speed of the cutting edge 1311 at the position corresponding to the axis of the continuous wire 20 is greater than the speed of change along the axial direction of the rotation axis 99. That is, at the position corresponding to the continuous wire 20, the movement of the cutting edge 1311 has two components: one component is along the axial direction of the rotation axis 99, and the other component is perpendicular to the rotation axis 99 and also substantially perpendicular to the axis of the continuous wire 20; this direction is along the circumference around the rotation axis 99. By making the speed of the cutting edge 1311 perpendicular to the rotation axis 99 greater than the speed of change along the axial direction of the rotation axis 99, it is equivalent to amplifying the force through a lever arm, which increases the cutting force of the cutting blade 131 on the continuous wire and improves the cutting efficiency. Furthermore, the axis of the continuous wire 20 is substantially perpendicular to the rotation axis 99 of the output shaft 89 (or the axis of the shaft hole 1312 of the cutting blade 131).

[0134] Figure 9aAs illustrated, the cutting blade 131 is mounted and fixedly connected to the output shaft 89 of the driver 80. For example, the driver 80 can be a servo motor, a stepper motor, or a servo motor. The driver 80 drives the cutting blade 131 along... Figure 9b or Figure 9d The arrow in the diagram rotates clockwise, causing the cutting blade's extension along the continuous filament 20 at the corresponding position to increase in length, thus cutting the continuous filament. For example... Figure 9b or Figure 9d The continuous filament 20 is cut, and then the cutting blade can rotate counterclockwise or continue to rotate clockwise to return to the initial state of avoiding the continuous filament 20, as shown. Figure 9a and 9c As shown, the continuous filament can be conveyed downwards.

[0135] Of course, it is understandable that in other embodiments, as shown in FIG11, the cutting edge 1311 may also be on the outside of the annular curved blade, such as... Figure 11b As shown, the blade 1311 is located on the side of the cutting blade 131 away from the rotation axis 99. Figure 12a This illustrates a cutting blade structure using an outer blade edge, such as... Figure 11b The cutting blade shown Figure 12a and 12c In the middle, the cutting blade is in a state of avoiding the continuous wire 20, and the continuous wire can be continuously conveyed. When cutting is required, the cutting blade 131 moves as follows: Figure 12b Alternatively, rotating clockwise within 12d increases the length of the cutting edge extending along the cutting blade axis towards the continuous wire, cutting the continuous wire by 20. After cutting, the cutting blade can continue to rotate clockwise or counterclockwise until... Figure 12a Alternatively, the cutting blade shown in 12c is in a state of avoiding continuous filament material, and continuous filament material is conveyed.

[0136] In this embodiment, the blade can be a smooth, continuous blade structure or a structure with tiny serrations, i.e., a serrated blade.

[0137] Cutting device embodiment 7:

[0138] The cutting device in this embodiment is basically the same as that in cutting device embodiment 6, except that the cutting blade 131 in this embodiment has two cutting edges 1311a and 1311b, which are used for cutting two different continuous filaments (first continuous filament 201 and second continuous filament 202), respectively. Furthermore, the two cutting edges 1311a and 1311b are oriented in different directions toward the rotation axis 99. Along the rotation direction of the cutting blade 131, the positions of the two cutting edges 1311a and 1311b change with the same trend on the rotation axis 99.

[0139] In this embodiment, the cutting blade 131 adopts the following... Figure 13a and Figure 13b The double-bladed structure shown has blade 1311a pointing away from the shaft hole 1312, and blade 1311b pointing towards the shaft hole 1312. The two blades can be curves that translate relative to each other. Furthermore, Figure 14a and Figure 14b As illustrated, the plane defining the axes of the first continuous filament 201 and the second continuous filament 202 is optimally aligned with or parallel to the rotation axis 99 of the cutting blade. Thus, when the cutting blade 131 rotates clockwise, the extension lengths of the blades 1311a and 1311b along the rotation axis 99 of the cutting blade at their corresponding positions on the feed tube 50 (or the continuous filament section) decrease. Since blade 1311a is located on the side of the first continuous filament 201 closest to the shaft hole 1312, it will not cut the first continuous filament 201. However, blade 1311b, located on the side of the second continuous filament 202 furthest from the shaft hole 1312, will cut the second continuous filament 202 due to its reduced axial extension along the rotation axis 99 of the cutting blade 131. When the cutting blade 131 rotates counterclockwise, the extension lengths of both blades 1311a and 1311b along the rotation axis 99 of the cutting blade increase at the feed tube (or continuous wire section). Since blade 1311a is located on the side of the first continuous wire 201 closer to the shaft hole 1312, the blade with the increased axial extension length along the rotation axis 99 of the cutting blade 131 will cut the first continuous wire 201. Meanwhile, blade 1311b is located on the side of the second continuous wire 202 farther from the shaft hole 1312 and will not cut the second continuous wire 202. Thus, a single cutting blade can achieve independent cutting control of two continuous wires by rotating in both directions. It features a compact structure, reliable operation, fast response, and convenient placement.

[0140] Cutting device embodiment 8:

[0141] This embodiment is basically the same as the cutting device embodiment 7, except that in this embodiment, the two blades 1311a and 1311b face the same direction along the rotation axis 99, and the positions of the two blades 1311a and 1311b change in opposite directions along the rotation axis 99 along the rotation direction of the cutting blade 131.

[0142] In this embodiment, Figure 15a and 15b The cutting blade can be illustrated by two symmetrically arranged blades. For example, blades 1311a and 1311b are symmetrically arranged with respect to a plane (i.e., a plane of symmetry) passing through the rotation axis 99 of the cutting blade 131. Two continuous wires (first continuous wire 201 and second continuous wire 202) are respectively arranged on both sides of the plane of symmetry, and are optimally conveyed downwards along a direction parallel to the plane of symmetry. Figure 15a and 15bThe blade extension length is greatest at the junction of the two blades 1311a and 1311b. Figure 15a In this design, two feed tubes 50, each containing a conduit for conveying continuous filaments, are used. Initially, the cutting blade 131 is positioned to avoid the two continuous filaments (first continuous filament 201 and second continuous filament 202). Specifically, the first continuous filament 201 and the second continuous filament 202 are positioned at points corresponding to the blade edges 1311b and 1311a, extending slightly beyond their respective directions along the rotation axis 99. Furthermore, the aforementioned plane of symmetry of the cutting blade 131 coincides with the plane of symmetry of the first continuous filament 201 and the second continuous filament 202. When the cutting blade rotates clockwise, the extension length of blade edge 1311a corresponding to the second continuous filament 202 decreases, preventing it from cutting the second continuous filament 202. Conversely, the extension length of blade edge 1311b corresponding to the first continuous filament 201 increases, allowing it to cut the first continuous filament 201. When the cutting blade rotates counterclockwise, the extension length of the blade 1311a corresponding to the second continuous filament 202 increases, and it can cut the second continuous filament 202. The extension length of the blade 1311b corresponding to the first continuous filament 201 decreases, and it will not cut the first continuous filament 201. Figure 15a In this design, when the cutting blade rotates continuously at a large angle clockwise or counterclockwise, it can cut two consecutive strands of wire one after the other. It features a compact structure, reliable operation, fast response, and convenient placement.

[0143] Cutting device embodiment 9:

[0144] The cutting device in this embodiment is basically the same as that in cutting device embodiment 8, except that in this embodiment... Figure 16a and 16b The blade extends the shortest distance at the junction of the two blades.

[0145] like Figure 16a As shown, initially, the cutting blade 131 is positioned to avoid the two continuous filaments. Furthermore, the aforementioned plane of symmetry of the cutting blade coincides with the plane of symmetry of the continuous filaments 201 and 202. When the cutting blade rotates clockwise, the extension length of the blade 1311a corresponding to the second continuous filament 202 increases, allowing it to cut the second continuous filament 202; the extension length of the blade 1311b corresponding to the first continuous filament 201 decreases, preventing it from cutting the first continuous filament 201. When the cutting blade 131 rotates counterclockwise, the extension length of the blade 1311a corresponding to the first continuous filament 202 decreases, preventing it from cutting the second continuous filament 202; the extension length of the blade 1311b corresponding to the first continuous filament 201 increases, allowing it to cut the first continuous filament 201. The design is compact, reliable, fast-responding, and easy to arrange.

[0146] A 3D printing head includes a feed tube 50 and a cutting device according to any one of embodiments 1-9. The feed tube 50 is used to transport the workpiece to be cut and has a notch for exposing continuous filament. A cutting edge 1311 rotates with a cutting blade 131 and cuts the continuous filament at the notch. More specifically:

[0147] 3D Printing Head Example 1:

[0148] A 3D printing head includes a feed tube 50 and a cutting device. The cutting device can be any of the cutting devices described in embodiments 1-6. Furthermore, the axis of the feed tube 50 is substantially parallel to the rotation axis 99 of the output shaft 89, and the distance between them remains fixed, or the positional relationship between the feed tube 50 and the driver 80 remains fixed. The feed tube 50 can convey continuous filament 20, for example, the continuous filament 20 can move downwards along arrow 98. In this embodiment, a lower tube 501 may also be provided, with a gap between the lower tube 501 and the feed tube 50, thereby forming a notch for exposing the continuous filament 20. The continuous filament 20 is fed downwards into the lower tube 501 and then further conveyed. Furthermore, the upper port of the lower tube 501 is coaxial with the lower port of the feed tube 50. Of course, it is understood that in other embodiments, the feed tube 50 and the lower tube 501 can be a single component, with a notch provided at the gap of the corresponding cutting blade 131 to form a notch for exposing the continuous filament 20, allowing the continuous filament 20 to be exposed here, and allowing the cutting blade 131 to be inserted, so that the cutting blade 131 can cut the continuous filament 20.

[0149] 3D Printing Head Example 2:

[0150] The 3D printing head in this embodiment is based on 3D printing head embodiment 1, such as... Figures 7a-7bAs shown, the bottom end of the feed tube 50 is provided with an inclined nozzle section 123, and the second extrusion port 1202 is provided on the inclined nozzle section 123. The inclined nozzle section 123 is fixed to the second heating block 14-2. For example, the inclined nozzle section 123 can be locked to the heating block 14-2 by screws 68. It also includes a bent tube 26 inserted into the heating block 14-2 and can be inserted into the inclined nozzle section 123. The bent tube 26 is fixed by the inclined nozzle section 123 and the heating block. The inclined nozzle section 123 has a through hole, preferably a straight through hole, which can be a stepped hole that narrows towards the direction of the second extrusion port. The axis of the second extrusion port 1202 can be parallel to or coaxial with the axis of the through hole in the inclined nozzle section 123, or parallel to the axis of the first extrusion port 1201 or vertically downward. The second extrusion port 1202 is connected to the pipeline inside the bent tube 26 via a through hole in the inclined nozzle section 123. The pipeline inside the bent tube 26 is bent. Ideally, the inclined portion of the pipeline is coaxial with the through hole in the inclined nozzle section 123, and the vertical portion of the pipeline in the bent tube 26 is coaxial with the pipeline inside the second feed tube section 128-2. By using the bent tube 26, a curved conveying connection of the feed tube from the second feed tube section to the second extrusion port is achieved. The bent tube 26 has a simple structure and is easy to implement. Moreover, the curved pipeline inside the bent tube 26 can easily achieve a smooth inner wall to ensure smooth conveying of the continuous fiber filament 22. At the same time, the inclined nozzle section 123 does not need to have a curved pipeline inside, simplifying manufacturing. It can be installed in an inclined manner, which greatly reduces the distance between the second extrusion port and the first extrusion port and allows the continuous fiber filament to be extruded smoothly at an inclined angle. Ideally, the bent tube 26 and the second feed tube section 128-2 (equivalent to the feed tube 50 in the aforementioned embodiment) have a gap. This gap is used to house the cutting blade 131 of the cutter 13, which cuts the continuous fiber filament 22 according to the fiber thread length during printing. That is, the continuous filament 20 in this embodiment is the continuous fiber filament 22. In addition, this gap can also effectively prevent the heat from the heating block 14-2 from being conducted upward to the second feed tube section 128-2. The heating block 14-2 can also be equipped with a heater 141-2 and a temperature sensor 142-2. For example, the heating block can be made of a material with good thermal conductivity such as copper or aluminum to heat the inclined nozzle section 123 and the bent tube 26 so that the continuous fiber filament is heated and extruded. With this structure, the tilted nozzle 123 is tilted and tilted towards the first extrusion port 1201, which greatly reduces the distance between the first extrusion port 1201 and the second extrusion port 1202. This greatly improves the ability of the two nozzles to adapt to printing paths with different bending radii, reduces the rotation angle of the nozzle seat ring 129, and allows the first extrusion port 1201 to extrude molten printing material more quickly and timely to cover the continuous fiber filament after the second extrusion port 1202 extrudes the continuous fiber filament. This is more conducive to the bonding and fusion of the molten printing material and the continuous fiber filament, and improves the strength of the model.Furthermore, during the printing process, the nozzle seat ring 129 drives the rotation of the first and second extrusion ports, keeping the second extrusion port 1202 in front and the first extrusion port 1201 behind. When the continuous fiber filament is extruded from the second extrusion port 1202, it is extruded at an angle towards the first extrusion port 1201. The bending angle of the continuous fiber during extrusion is no longer 90 degrees, but a smaller bending angle is sufficient. The extrusion process of the continuous fiber is smoother and it is easier to avoid accidental cutting, breakage, or damage during the extrusion of the continuous fiber, which helps to improve the stability of the printing process and the quality of the printed model. The first feed tube 128-1 or the second feed tube 128-2 can be fixedly connected to the nozzle seat ring 129. The nozzle seat ring 129 can be rotatably connected to the print base 11 through the bearing 45-2. A sensor 82 can also be fixedly connected to the nozzle seat ring 129. In this case, the wire 85 can pass through the through hole 19 of the nozzle seat ring and be connected to the sensor 82. The passive detection component 83 can be fixedly connected to the print base 11. A cooling fan 18 can also be fixedly connected to the nozzle seat ring 129, with the air outlet facing the direction of the printing material just extruded from the first and second extrusion ports. Of course, the nozzle seat ring 129 is not necessary; the first feed tube section 128-1, the second feed tube section 128-2, the first heating block, or the second heating block can also be fixedly connected to the print base 11.

[0151] The cutter 13 is controlled according to the fiber arrangement instructions during the printing process. For example, the cutter 13 can be controlled by a wire (wire harness) 85 passing through the through hole 19, so that the cutting blade 131 of the cutter 13 penetrates into the gap between the curved tube 26 and the second feed tube section 128-2, cutting the continuous fiber filament 22 fed from the second feed tube section 128-2 to the curved tube 26. Specifically, as shown in the figure... Figure 8a and 8b As shown, Figure 8a and 8b It can be seen as Figure 7a , 7b Or a bottom view of 7c, and for ease of display, the second heating block 14-2, the second heater 141-2, and the temperature sensor 142-2 are omitted from the figure. Combined with Figure 7a , 7b Alternatively, in configuration 7c, the cutting blade 131 is mounted on the output shaft 89 of the servo 56. The servo 56 is fixedly connected to the nozzle seat ring 129, either directly or via a mounting block 127 or other components. The output shaft 89 of the servo 56 is rotatable, allowing the servo 56 to drive the cutting blade 131 to rotate. The distance (radius) from the outermost edge of the cutting blade 131 to the output shaft 89 varies, thus changing the distance the cutting blade extends into the gap between the bent tube 26 and the second feed tube section 128-2 as the cutting blade rotates. Figure 8a and Figure 7cOr, as shown in Figure 7d, the cutting blade 131 is positioned such that it does not contact the continuous fiber filament 22 at the gap between the bent tube 26 and the second feed tube section 128-2. The continuous fiber filament 22 can be freely fed into the bent tube 26 from the second feed tube section 128-2 and then extruded by the inclined nozzle section 123, or directly extruded from the bent tube 26. When the continuous fiber filament needs to be cut, the servo 56 drives the output shaft 561 to rotate, which in turn drives the cutting blade 131 to rotate. Figure 8a and 7c When the cutting blade 131 is rotated clockwise as indicated by the arrow on the cutting blade 131, when the cutting blade 131 rotates to the position shown by the arrow... Figure 8b As shown, the area with a sufficiently large radius of the cutting blade 131 reaches the gap between the bend 26 and the second feed tube 128-2, that is, the cutting blade 131 extends into the gap between the bend 26 and the second feed tube 128-2 to cut the continuous fiber filament. Then the cutting blade 131 can rotate in the opposite direction to allow the area with a large radius to leave the gap between the bend 26 and the second feed tube 128-2, returning to the position shown. Figure 8a In the state shown, the continuous fiber filament can continue to be conveyed to the bend 26 through the second feed tube 128-2 on the right. Figure 7c As can be seen, optimally, the diameter of the second feed tube section 128-2 (i.e., feed tube 50) is smaller than the diameter of the corresponding section of the bend 26. Furthermore, to facilitate the feeding of the continuous filament 20 into the bend 26 after cutting, a chamfer 505 is provided at the upper end of the bend 26 to guide the continuous filament feeding. The first heating block 14-1 and the second heating block 14-2 can be fixed to the nozzle seat ring 129 via the first pin 27-1 and the second pin 27-2, for example, via the mounting block 127. Simultaneously, the cutter 56 is also fixed to the nozzle seat ring. Alternatively, the first heating block 14-1 and the second heating block 14-2 can be fixed to the print base 11 via the first pin 27-1 and the second pin 27-2, respectively. Simultaneously, the cutter 56 is also fixed to the print base 11.

[0152] 3D Printing Head Example 3:

[0153] The 3D printing head of this embodiment includes a feed tube and a cutting device. The cutting device in this embodiment can be any of the cutting devices in embodiments 2-5 and 7-9, used for cutting two continuous filaments (first continuous filament 201 and second continuous filament 202). Regarding the feed tube in this embodiment, such as... Figure 3b As shown, in some embodiments, two feed pipes, such as feed pipes 501 and 502, can be provided to convey the first continuous filament 201 and the second continuous filament 202, respectively. In other embodiments, two pipes can also be provided within feed pipe 50, such as... Figure 4 and Figure 14b As shown, they are used to convey the first continuous filament 201 and the second continuous filament 202, respectively.

[0154] 3D Printing Head Example 4:

[0155] Figure 7d and Figure 17 The illustration also suggests that the cutting blade can be positioned at the extrusion port of the nozzle 121 to cut the continuous filament 20 (e.g., continuous fiber filament). A stepped structure 1314 can be provided on the cutting blade 131 so that the cutting edge can sink to the extrusion port of the nozzle 121, while the servo 56 and its shaft, as well as the screw 68 that fixes the cutting blade, can be moved upwards. This avoids the screw 68 or the servo 56 being too low and affecting the normal printing process of the nozzle 121. This embodiment allows the allowance length for cutting continuous filament to be shorter or even zero. Figure 7d The rotation axis 99 of the cutting blade is roughly parallel to the axis of the continuous filament 20. The cutting blade 121 has a blade-type structure. Figure 17 The rotation axis 99 of the cutting blade is roughly perpendicular to the axis of the continuous filament 20, and the cutting blade 121 has a ring structure.

[0156] 3D Printing Head Example 5:

[0157] The 3D printing head of this embodiment includes a feed tube and a cutting device. The cutting device in this embodiment can be any of the cutting devices in embodiments 6-9 (i.e., a cutting blade with a ring structure).

[0158] Furthermore, such as Figure 9a As shown, in some embodiments, the lower end face of the feed tube 50, facing the side of the cutting blade closest to the axis of rotation in the radial direction of its rotation (i.e., the inner ring surface of the ring-shaped cutting blade), is a spherical or cylindrical surface that matches the cutting blade 131. Figure 9a The middle cutting blade 131 avoids the continuous filament 20, which can be conveyed by the feed tube 50 to the lower tube 501 and the nozzle 121 for extrusion. Furthermore, the heater 141 and temperature sensor 142 provided on the heating block 14 between the lower tube 501 and the nozzle 121 are used for heating temperature control.

[0159] In other implementations, such as Figure 14a and Figure 14b As shown, the surface at the lower end of the feed tube 50 that matches the cutting blade is a cylindrical or spherical surface that matches the outer annular surface of the cutting blade. The lower end surface of the feed tube 50 mates with the outer annular surface of the cutting blade for cutting. Alternatively, the surface at the lower end of the feed tube 50 that matches the cutting blade can also be a cylindrical (or spherical) surface that matches the inner annular surface of the cutting blade, and the lower end surface of the feed tube 50 mates with the inner annular surface of the cutting blade for cutting, similar to... Figures 9a to 9c As shown.

[0160] In other implementations, such as Figure 12a As shown, when using a cutting blade structure with an outer blade edge, if using... Figure 11b The cutting blade shown can be further described as follows: the upper end face of the lower tube 501 can be a spherical or cylindrical surface that matches the inner side of the cutting blade, and the lower end face of the material tube 50 can be a cylindrical surface that matches the outer side of the cutting blade.

[0161] In other implementations, such as Figure 12e As shown, a cutting ring 509 can be provided on the outside of the cutting blade 131. The cutting blade and the cutting ring are rotatably clearance-fitted. The cutting ring has an inlet hole corresponding to the material tube 20, and an outlet hole is provided below. Figure 12e The image shows the state where the cutting blade cuts the continuous filament 20.

[0162] The blades in the above embodiments can have a structure with tiny serrations, i.e., so-called serrated blades, which can achieve faster cutting, cleaner cutting surfaces, or lower cutting force. In this text, "generally" refers to something that is theoretically precise but actually has errors in manufacturing or installation, such as an error of less than ±45° or less than ±15°.

[0163] Continuous filament (or wire) can be continuous fiber, or continuous fiber printing material made from prepreg, etc. The cross-section of the continuous filament can be circular or non-circular, such as polygonal, square, or rectangular. The length of the continuous filament is greater than the diameter of the outer envelope circle of the cross-section; optimally, the length of the continuous filament is greater than 10 times the diameter of the outer envelope circle. Continuous filament can be fiber material, metal wire material (such as copper wire), optical fiber material, or other continuous linear material, and can be resin-prepreg continuous fiber material. Continuous fiber materials can be carbon fiber, glass fiber, polyester, aramid, ceramic fiber, boron fiber, or basalt fiber, or metal fiber, SiC fiber, conductive polymer fiber, graphite fiber, boron fiber, or silicon nitride fiber, etc. The matrix material used for prepreg of continuous fibers can be thermoplastic resin materials, such as PLA (polylactic acid), PP (polypropylen), PE (polyethylene), ABS (Acrylonitrile Butadiene Styrene), PA (Polyamide) (nylon), PC (Polycarbonate), PS (Polystyrene), PEI (Poly(etherimide)), PET (Poly(Ethylene Terephthalare)), PEEK (Polyetheretherketone), TPU (Thermoplastic polyurethanes), etc., or epoxy resin, or thermosetting resin materials or photosensitive polymeric resin materials, or other flowable extruded materials, or metals or low-melting-point alloys, or acrylic ester-based shape memory polymers, or thiol-olefin-based shape memory polymers.

[0164] The use of directional terms such as "above," "below," "left," and "right" in the text is for convenience in describing the specific accompanying drawings and is not intended to limit the invention. In practical applications, due to spatial changes in the overall structure, the actual left or right position may differ from that shown in the drawings. However, these changes should all be within the scope of protection of this invention. It should be noted that the above embodiments can be freely combined as needed. The above descriptions are merely preferred embodiments of the invention. It should be pointed out that those skilled in the art can make various improvements and modifications without departing from the principles of the invention, and these improvements and modifications should also be considered within the scope of protection of this invention.

Claims

1. A 3D printing head, characterized in that, The device includes a feed tube and a cutting device for cutting continuous filaments configured to be conveyed along their axial direction. The cutting device comprises a cutting blade rotatable about a rotation axis, the positional relationship between the rotation axis and the axis of the continuous filaments being fixed. The cutting blade has at least one cutting edge, and the position of the cutting edge gradually changes relative to the rotation axis along the rotation direction of the cutting blade, such that the distance from the cutting edge to the axis of the continuous filaments at a position corresponding to the axis of the continuous filaments gradually changes. The cutting blade has a ring-shaped structure. The blade faces the axial direction of the rotation axis. Along the rotation direction of the cutting blade, the distance from the blade to the rotation axis is equal, and the position of the blade gradually changes in the axial direction of the rotation axis. The feed tube is used to transport the continuous filament, and the feed tube has a notch for exposing the continuous filament. The blade rotates with the cutting blade and cuts the continuous filament at the notch.

2. The 3D printing head as described in claim 1, characterized in that, During the rotation of the cutting blade around the rotation axis, the circumferential speed of the blade at the position corresponding to the axis of the continuous filament is greater than the speed of change along the axial direction of the rotation axis.

3. The 3D printing head as described in claim 1, characterized in that, The blade is shaped as a segment of a cylindrical helix, or the blade is shaped as a segment of the edge of a cylindrical oblique section.

4. The 3D printing head as described in claim 1, characterized in that, The curve containing the blade is located on a toroidal surface.

5. The 3D printing head as described in claim 1, characterized in that, The cutting edge is located on the side of the cutting blade closer to the axis of rotation, or the cutting edge is located on the side of the cutting blade away from the axis of rotation.

6. The 3D printing head as described in claim 1, characterized in that, The cutting tool has two cutting edges, each used for cutting two continuous wires: When the two blades are oriented in the same direction along the axis of rotation, the positions of the two blades change in opposite directions along the axis of rotation.

7. The 3D printing head as described in claim 6, characterized in that, The two blades are symmetrical with respect to a plane passing through the axis of rotation.

8. The 3D printing head as described in claim 7, characterized in that, The two continuous filaments are respectively positioned at a shorter position that extends along the rotation axis in the direction corresponding to the blade.

9. The 3D printing head as described in claim 1, characterized in that, The cutting tool has two cutting edges, each used for cutting two continuous wires: When the two blades are oriented in opposite directions along the axis of rotation, the positions of the two blades change in the same trend along the axis of rotation along the direction of rotation of the cutting blade.

10. The 3D printing head as described in claim 9, characterized in that, The two blades have the same shape, and the distance between the two blades along the axial direction of the rotation axis is equal everywhere.

11. The 3D printing head as described in claim 10, characterized in that, The two continuous filaments are arranged sequentially along the axial direction of the rotation axis.

12. The 3D printing head as described in claim 1, characterized in that, The rotation axis is perpendicular to the axis of the continuous filament or at an angle within the range of 45°-135°.

13. The 3D printing head as described in claim 1, characterized in that, The blade is either a smooth, continuous blade or a serrated blade.

14. The 3D printing head as described in claim 13, characterized in that, The serration height of the serrated blade is less than the diameter of the continuous filament, and / or the envelope formed at the top or tip of the serration is a segment of a gradient curve.

15. The 3D printing head as described in claim 14, characterized in that, The gradient curve includes an involute, a spiral, or an eccentric circle.

16. The 3D printing head as claimed in claim 1, characterized in that, The cutting device further includes a driver having a rotatable output shaft connected to the cutting blade to drive the cutting blade to rotate.

17. The 3D printing head as described in claim 16, characterized in that, The driver includes a servo motor, a stepper motor, or a servo motor.

18. The 3D printing head as described in claim 16, characterized in that, The cutting blade has a shaft hole for fitting onto the output shaft of the driver.

19. The 3D printing head as described in claim 1, characterized in that: The feed tube includes a first feed tube and a second feed tube, which are arranged coaxially and have a gap between them. The gap forms the notch, and the continuous filament is conveyed from the first feed tube to the second feed tube. Alternatively, the side wall of the feed tube is provided with a notch to expose the continuous filament at the notch, and the notch forms the gap; Alternatively, one end of the feed tube is provided with a nozzle, the extrusion port of the nozzle is used for the material output of the 3D printing head, and the extrusion port forms the notch.

20. The 3D printing head as described in claim 19, characterized in that: The cutting blade has a stepped structure between the blade edge and the position where the rotation axis passes through the cutting blade, so that the position where the rotation axis passes through the cutting blade is away from the extrusion port.

21. The 3D printing head as described in claim 19, characterized in that, When the cutting edge is facing the axis of rotation or the cutting edge is facing away from the axis of rotation; as the distance from the cutting edge to the axis of rotation gradually changes along the rotation direction of the cutting blade: The material tube has a first material tube end face at one end of the notch, and the cutting edge is located on the edge of the cutting blade facing the first material tube, and the first material tube end face is flat; or, the material tube has a second material tube end face at the other end of the notch, and the cutting edge is located on the edge of the cutting blade facing the second material tube, and the second material tube end face is flat.

22. The 3D printing head as described in claim 19, characterized in that, When the blade is oriented axially towards the axis of rotation, the distance from the blade to the axis of rotation is equal along the direction of rotation of the cutting blade, and the position of the blade gradually changes in the axial direction of the axis of rotation: The feed tube has a first feed tube end face at one end of the notch. The first feed tube end face faces the side of the cutting blade that is close to the axis of rotation in the radial direction of its rotation. The first feed tube end face is a cylindrical or spherical surface that matches the cutting blade. Alternatively, the feed tube has a first feed tube end face at one end of the notch, the first feed tube end face facing the side of the cutting blade away from the axis of rotation in the radial direction of its rotation, and the first feed tube end face is a cylindrical or spherical surface that matches the cutting blade. Alternatively, the feed tube has a second feed tube end face at the other end of the notch, the second feed tube end face facing the side of the cutting blade away from the axis of rotation in the radial direction of its rotation, and the second feed tube end face is a cylindrical or spherical surface that matches the cutting blade; Alternatively, the feed tube has a second feed tube end face at the other end of the notch, the second feed tube end face facing the side of the cutting blade close to the axis of rotation in the radial direction of its rotation, and the second feed tube end face is a cylindrical or spherical surface that matches the cutting blade.

23. The 3D printing head as described in claim 22, characterized in that, The material tube is provided with a cutting ring at the notch, and the side wall of the cutting ring is provided with an inlet hole or an outlet hole corresponding to the material tube. The cutting blade is disposed inside the cutting ring and is rotatably clearance-fitted with the cutting ring. The inner side of the cutting ring at the inlet hole or the outlet hole forms the first material tube end face, or the inner side of the cutting ring at the inlet hole or the outlet hole forms the second material tube end face.

24. The 3D printing head as described in claim 1, characterized in that, The material tube is provided with two pipes; or two material tubes are provided, each of which is provided with one pipe.

25. The 3D printing head as described in claim 1, characterized in that: The feed tube includes a feed tube section and a bend. The pipe inside the bend is a bend. The pipe in the vertical part of the bend is coaxial with the pipe inside the feed tube section. There is a gap between the bend and the feed tube section. The cutting blade can penetrate into the gap between the bend and the feed tube section to cut the continuous fiber material conveyed from the feed tube section to the bend.

26. The 3D printing head as described in claim 25, characterized in that: It also includes a printhead, a nozzle seat ring, and a driver. The nozzle seat ring is rotatably connected to the printhead via a bearing. The driver and the feed tube are fixedly connected to the nozzle seat ring. The bent tube is inserted into the heating block, and the heating block is fixedly connected to the nozzle seat ring via a second pin. The driver drives the cutting blade to rotate. When the cutting blade rotates, the distance by which the cutting blade extends into the gap between the bent tube and the feed tube changes.

27. The 3D printing head as described in claim 25, characterized in that: A chamfer is provided at the upper end of the bend to guide the continuous filament material in.

28. The 3D printing head as described in claim 25, characterized in that: It also includes an inclined nozzle section, which has a through hole, and the pipe of the inclined portion of the bend is coaxial with the through hole in the inclined nozzle section.

29. The 3D printing head as described in claim 28, characterized in that: It also includes a first extrusion port and a second extrusion port, the second extrusion port being disposed on the inclined nozzle portion, the inclined nozzle portion being in an inclined state and inclined toward the direction of the first extrusion port.

Images