Method for 3D printer and 3D printer device

Abstract

A method for a 3D printer. The 3D printer includes: a print head, defining a wire channel for feeding wire through, the wire channel including a first end and a second end opposite to the first end, the wire will be melted at the second end, and the wire channel is provided with a seam caused by the joining of different components of the print head; an extruder, configured to feed the wire into the wire channel via the first end and extrude the wire via the second end; and a wire cutter, arranged between the extruder and the print head. The method includes: causing the wire cutter to cut the wire into a first wire segment outside the wire channel and a second wire segment at least partially located in the wire channel; causing the extruder to feed the first wire segment into the wire channel via the first end of the wire channel, so that the second wire segment is pushed by the first wire segment toward the second end of the wire channel to a position beyond the seam; and causing the extruder to withdraw the first wire segment out of the wire channel.

Description

Technical Field

[0001] The present disclosure relates to the technical field of 3D printing, and in particular to a method for a 3D printer, a 3D printer, a computer-readable storage medium, and a computer program product. Background Art

[0002] 3D printer, also known as three-dimensional printer, stereo printer, is a kind of rapid prototyping process equipment, usually realized by printing materials with digital technology. 3D printers are often used to make models or parts in the fields of mold manufacturing, industrial design, etc. In recent years, 3D printing technology has great application prospects in jewelry, footwear, industrial design, architecture, engineering and construction (AEC), automobiles, aerospace, dental and medical industries, education, geographic information systems, civil engineering, firearms and other fields.

[0003] The 3D printing method known in the art, Fused Deposition Modeling (FDM), is a method of constructing a 3D object by printing layer by layer using materials such as powdered metal or plastic based on a digital model, wherein the 3D printer used supplies the molding material to the print head in the form of filaments, and the molding material is heated to a molten state by electric heating in the print head. The print head prints the 3D object layer by layer according to the path of movement of the print head relative to the substrate generated by the controller of the 3D printer.

[0004] During the material changing process, the 3D printer first needs to retract some of the molten wire. Due to the temperature differences among various parts of the print head and the gaps at the combination of various parts, some of the molten wire may block the gaps, thereby causing the wire channel to be blocked, and ultimately making it impossible to continue the subsequent material changing operation. Summary of the invention

[0005] The present disclosure provides a method for a 3D printer, a 3D printer device, a computer-readable storage medium, and a computer program product.

[0006] According to one aspect of the present disclosure, the present disclosure provides a method for a 3D printer.

[0007] The 3D printer includes: a print head, defining a wire channel for feeding wire through, the wire channel including a first end and a second end opposite to the first end, the wire will be melted at the second end, and the wire channel is provided with a seam caused by the joining of different components of the print head; an extruder, configured to feed the wire into the wire channel via the first end and extrude the wire via the second end; and a wire cutter, arranged between the extruder and the print head. The method includes: causing the wire cutter to cut the wire into a first wire segment outside the wire channel and a second wire segment at least partially located in the wire channel; causing the extruder to feed the first wire segment into the wire channel via the first end of the wire channel, so that the second wire segment is pushed by the first wire segment toward the second end of the wire channel to a position beyond the seam; and causing the extruder to withdraw the first wire segment out of the wire channel.

[0008] According to another aspect of the present disclosure, a 3D printer is also provided, comprising: a print head, defining a wire channel for passing a wire, the wire channel comprising a first end and a second end opposite to the first end, the wire will be melted at the second end, and the wire channel is provided with a seam caused by the joining of different components of the print head; an extruder, configured to feed the wire into the wire channel via the first end and extrude the wire via the second end; a wire cutter, arranged between the extruder and the print head, and configured to cut the wire; and a processor, configured to execute instructions to implement the above method.

[0009] According to yet another aspect of the present disclosure, a non-transitory computer-readable storage medium is provided, on which instructions are stored, wherein the instructions implement the method described above when executed by a processor of the 3D printer described above.

[0010] According to yet another aspect of the present disclosure, a computer program product is provided, comprising instructions, wherein the instructions implement the method described above when executed by a processor of the 3D printer described above.

[0011] According to the embodiment of the present disclosure, when the 3D printer performs material change, the material cutting operation is first performed, the cut wire material is divided into a first wire material segment outside the wire material channel and a second wire material segment at least partially located in the wire material channel, the second wire material segment is pushed toward the second end of the wire material channel to a position exceeding the seam by the wire material segment of the first wire material segment, and finally the first wire material segment is pulled back out of the wire material channel. In this way, the wire material is prevented from blocking the wire material channel, thereby achieving smooth material change.

[0012] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in accordance with the present disclosure and should not be regarded as limiting the scope of the present disclosure.

[0014] Figure 1 A schematic structural diagram of a 3D printer according to an exemplary embodiment of the present disclosure is shown;

[0015] Figure 2 A flow chart of a method for a 3D printer according to an exemplary embodiment of the present disclosure is shown;

[0016] Figure 3 According to an exemplary embodiment of the present disclosure, Figure 2 A flowchart of an example process of cutting a wire in the method;

[0017] Figure 4a A schematic diagram showing a method for a 3D printer according to an exemplary embodiment of the present disclosure is shown;

[0018] Figure 4b A schematic diagram showing a method for a 3D printer according to an exemplary embodiment of the present disclosure is shown;

[0019] Figure 4c A schematic diagram showing a method for a 3D printer according to an exemplary embodiment of the present disclosure is shown;

[0020] Figure 4d A schematic diagram showing a method for a 3D printer according to an exemplary embodiment of the present disclosure is shown;

[0021] Figure 5 According to an exemplary embodiment of the present disclosure, Figure 2 A flowchart of another example process of cutting a wire in the method;

[0022] Figure 6 A flow chart showing a method for a 3D printer according to another exemplary embodiment of the present disclosure is shown;

[0023] Figure 7 A flowchart showing a method for a 3D printer according to another exemplary embodiment of the present disclosure; and

[0024] Figure 8 A flow chart showing a method for a 3D printer according to another exemplary embodiment of the present disclosure is shown; DETAILED DESCRIPTION

[0025] The following is a description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope of the present disclosure. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0026] In the present disclosure, unless otherwise specified, the use of the terms "first", "second", etc. to describe various elements is not intended to limit the positional relationship, timing relationship, or importance relationship of these elements, and such terms are only used to distinguish one element from another element. In some examples, the first element and the second element may refer to the same example of the element, and in some cases, based on the description of the context, they may also refer to different examples.

[0027] The terms used in the description of various examples in this disclosure are only for the purpose of describing specific examples and are not intended to be limiting. Unless the context clearly indicates otherwise, if the number of elements is not specifically limited, the element can be one or more. In addition, the term "and / or" used in this disclosure covers any one of the listed items and all possible combinations.

[0028] In practice, 3D printers need to return the wire material currently in use before changing materials. In the related art, the old wire material is first withdrawn and then cut to reduce the waste of wire material. Then wait for the loading of new wire material. After the new wire material is loaded, the old wire material that was previously cut off and remains in the wire material channel is pushed to the nozzle through the new wire material to achieve the material change step of 3D printing. The inventor found that this brings the following problems: Since the wire material channel contains gaps caused by the joints of multiple components, when the old wire material is withdrawn, part of the old wire material is in a molten state. During the time waiting for the new wire material to be loaded, the wire material in a molten state will become solid due to cooling, blocking the seam, thereby blocking the wire material channel and affecting the subsequent material change step.

[0029] In view of this, the embodiments of the present disclosure provide a 3D printer 100 and a method for a 3D printer, which can alleviate, mitigate or even eliminate the above-mentioned problems.

[0030] Figure 1 A schematic diagram of the structure of a 3D printer 100 according to an embodiment of the present disclosure is shown. Figure 1 The 3D printer 100 is described in detail.

[0031] like Figure 1As shown, the 3D printer 100 includes: a processor (not shown in the figure), an extruder 102 , a wire cutter 103 , a print head 107 and a printing platform 109 .

[0032] The extruder 102 may be provided with an extrusion gear train, which may be driven by a motor (not shown) controlled by a processor, for example, to perform a feeding or unloading operation. In the feeding operation, the wire material 101 is fed toward the print head 107 by the extruder 102, and in the unloading operation, the wire material 101 is withdrawn from the print head 107 by the extruder 102.

[0033] The print head 107 defines a wire channel 105 for passing the wire 101. The wire channel 105 includes a first end 104 and a second end 108 opposite to the first end 104. The second end 108 is provided with a heater so that the wire 101 will be melted at the second end 108. The wire channel 105 is also provided with a seam 106 caused by the joining of different components of the print head 107.

[0034] The wire cutter 103 is arranged between the extruder 102 and the print head 107. In this embodiment, for the convenience of description, the direction from the second end 108 to the first end 104 is defined as the Z-axis direction. The wire cutter 103 can be driven by a motor (not shown) controlled by a controller, for example, to move in a plane perpendicular to the Z-axis direction, thereby cutting the wire 101.

[0035] The printing platform 109 is arranged at the bottom of the 3D printer 100, and is used to support the object to be printed, and its upper surface is a printing plane. The printing platform 109 may include a material change area (not shown in the figure). The space above the printing platform 109 includes a printing space for printing the object to be printed and a material change space for changing the line material. In this embodiment, the combination of the print head 107 and the extruder 102 can move in the printing space and the material change space.

[0036] Although in Figure 1 The extruder 102 is shown as being disposed above the print head 107, but other embodiments are possible. For example, in a remote feeding embodiment, the extruder 102 may be disposed away from the print head 107. It will also be understood that Figure 1 The center seam 106 is schematically shown, and in practice, the seam 106 may have a different size and position than shown.

[0037] The processor (not shown in the figure) is configured to perform operations when executing instructions, and the above operations include: causing the wire cutter 103 to cut the wire 101 into a first wire segment outside the wire channel 105 and a second wire segment at least partially located in the wire channel 105; causing the extruder 102 to feed the first wire segment into the wire channel 105 via the first end 104 of the wire channel 105, so that the second wire segment is pushed by the first wire segment toward the second end 108 of the wire channel 105 to a position exceeding the seam 106; and causing the extruder 102 to pull the first wire segment back out of the wire channel 105.

[0038] Figure 2 A flow chart of a method 200 for a 3D printer 100 according to an exemplary embodiment of the present disclosure is shown. The method 200 may include the following steps.

[0039] In step 201 , the wire cutter 103 is caused to cut the wire 101 into a first wire segment outside the wire channel 105 and a second wire segment at least partially located in the wire channel 105 .

[0040] Reference Figure 4a and 4b , Figure 4a It is shown that the wire cutter 103 performs a horizontal rightward cutting operation 41 so that the wire cutter 103 cuts the wire 101. At this time, the wire 101 exceeds the position of the joint 106 at the bottom end of the wire channel 105 in the direction opposite to the Z-axis direction. Figure 4b It is shown that the wire cutter 103 cuts the wire 101 into two wire segments.

[0041] In step 202 , the extruder 102 feeds the first strand segment into the strand channel 105 via the first end 104 of the strand channel 105 , so that the second strand segment is pushed by the first strand segment toward the second end 108 of the strand channel 105 to a position beyond the seam 106 .

[0042] Reference Figure 4c , Figure 4c It is shown that the wire cutter 103 performs operation 43, so that the wire cutter 103 is horizontally retracted to the left. At this time, the wire 101 has been cut by the cutter 103 into a first wire segment 110 and a second wire segment 111. Then the extruder 102 is powered by the motor to feed the first wire segment 110 in the reverse direction of the Z axis, that is, to perform operation 44 to transport it downward.

[0043] Reference Figure 4d , Figure 4dIt is shown that after the extruder 102 performs operation 44, the first strand segment 110 pushes the second strand segment 111 to a position beyond the joint 106 along the opposite direction of the Z axis. At this time, the second strand segment 111, which may be in a molten state, will not block the joint 106, and will eventually leave the strand channel 105 after the new strand is loaded. In this way, blocking the joint 106 and thus blocking the strand channel 105 is avoided.

[0044] In step 203, the extruder is caused to withdraw the first strand segment out of the strand channel.

[0045] Continue to refer Figure 4d , Figure 4d It is shown that after the second strand segment 111 is pushed away from the position of the joint 106 in the reverse direction of the Z axis, the extruder 102 controls the first strand segment 110 to be withdrawn in the Z axis direction, that is, the operation 45 is performed to convey upward until the first strand segment 110 is completely withdrawn. After the second strand segment 111 is pushed away from the position of the joint 106, the operation 45 can be quickly performed to withdraw the first strand segment 110 in the Z axis direction, thereby preventing the first strand segment 110 from being heated to a molten state. In this way, the old material is withdrawn, and the 3D printer can load new strands.

[0046] Figure 3 A flowchart of an exemplary process 201a of cutting a wire in step 201 of method 200 according to an exemplary embodiment of the present disclosure is shown. Process 201a may include the following steps.

[0047] In step 301 , the wire cutter 103 is moved from an initial position to a working position to cut the wire.

[0048] refer to Figure 4a , the wire cutter 103 performs a horizontal rightward cutting operation 41, resulting in a horizontal displacement to the right, that is, the wire cutter 103 starts to move from the initial position to the working position.

[0049] In step 302 , while keeping the strand cutter 103 in the working position, the extruder 102 is caused to withdraw the strand 101 in a direction away from the second end 108 of the strand channel 105 to ensure that the strand 101 is cut into the first strand segment 110 and the second strand segment 111 .

[0050] refer to Figure 4b , the wire cutter 103 remains in the working position. In order to ensure that the wire 101 is cut by the wire cutter 103, the extruder 102 performs operation 42 to withdraw the wire 101 in the direction opposite to the Z-axis direction, so that the wire segment above the wire cutter 103 is completely separated from the wire segment below the wire cutter 103. Figure 4c, the wire segment located above the wire cutter 103 is a first wire segment 110 , and the wire segment located below the wire cutter 103 is a second wire segment 111 .

[0051] In step 303, the wire cutter is returned from the working position to the initial position.

[0052] Continue to refer Figure 4c , Figure 4c The wire cutter 103 performs operation 43, so that the wire cutter 103 is horizontally retracted to the left, that is, it returns to the initial position from the working position. Figure 4d shown.

[0053] Figure 5 A flowchart of another example process 201b of cutting a wire in step 201 of method 200 according to an exemplary embodiment of the present disclosure is shown. Process 201b may include the following steps:

[0054] In step 501 , the wire cutter 103 is moved back and forth between an initial position and a working position for cutting the wire 101 for a predetermined number of times to ensure that the wire 101 is cut into a first wire segment 110 and a second wire segment 111 .

[0055] In step 502, the wire cutter 103 is returned from the working position to the initial position.

[0056] In some cases, the wire cutter 103 may not be able to cut the wire 101 at one time to obtain the first wire segment 110 and the second wire segment 111. In order to ensure that the wire 101 is cut into two wire segments, the wire cutter 103 may be allowed to go back and forth between the initial position and the working position for multiple cuttings. Then, the wire cutter 103 returns to the initial position.

[0057] Figure 6 A flowchart of a method 600 for a 3D printer 100 according to another exemplary embodiment of the present disclosure is shown. The method 600 may include the following steps:

[0058] In step 601 , the wire cutter 103 is caused to cut the wire 101 into a first wire segment 110 outside the wire channel 105 and a second wire segment 111 at least partially located inside the wire channel 105 .

[0059] In step 602, the print head 107 and the printing platform 109 are translated relative to each other so that the print head 107 is positioned above the refill area.

[0060] In step 603 , the extruder 102 feeds the first strand segment 110 into the strand channel 105 via the first end 104 of the strand channel 105 , so that the second strand segment 111 is pushed by the first strand segment 110 toward the second end 108 of the strand channel 105 to a position beyond the seam 106 .

[0061] In step 604 , the extruder 102 is caused to withdraw the first strand segment 110 out of the strand channel 105 .

[0062] According to some embodiments, in order to reduce wire material contamination, a material change area different from the printing area needs to be set on the printing platform 109, so that the 3D printer 100 performs the 3D printing function in the printing area and performs material return and change operations in the material change area.

[0063] In such an embodiment, before executing step 603 to cause the extruder 102 to feed the first wire segment 110 into the wire channel 105 through the first end 104 of the wire channel 105, step 602 can be executed first to cause the print head 107 and the printing platform 109 to translate relative to each other so that the print head 107 is positioned above the material exchange area.

[0064] In one embodiment, the 3D printer 100 can provide power through a motor to control the movement of the print head 107, move the print head 107 from the printing area to above the material changing area, and perform material removal and material changing operations.

[0065] In one embodiment, the 3D printer 100 can provide power through a motor to control the movement of the printing platform 109, move the material changing area of ​​the printing platform 109 to below the print head 107, and then perform material removal and material changing operations.

[0066] In one embodiment, the 3D printer 100 can be powered by a motor and control the movement of the printing platform 109 and the print head 107 at the same time, so that the print head 107 is located above the material changing area to perform material removal and material changing operations.

[0067] According to some embodiments, Figure 4a As shown, the lower end of the wire material 101 (in a molten state) is already at the position of the joint 106. In the process of positioning the print head 107 above the material replacement area, the lower end of the wire material 101 in a molten state may be cooled and solidified, thereby blocking the joint 106. To avoid this possibility, step 602 can be performed before step 601.

[0068] According to some embodiments, the sequence of steps at this time is: first, the print head 107 and the printing platform 109 are translated relative to each other so that the print head 107 is positioned above the material changing area; then, the wire cutter 103 cuts the wire 101 into a first wire segment 110 and a second wire segment 111; then, the extruder 102 feeds the first wire segment 110 into the wire channel 105, so that the second wire segment 111 is pushed by the first wire segment 110 toward the second end 108 of the wire channel 105 to a position exceeding the seam 106; and the extruder 102 pulls the first wire segment 110 back out of the wire channel 105.

[0069] Figure 7 A flowchart of a method 700 for a 3D printer 100 according to another exemplary embodiment of the present disclosure is shown. The method 700 may include the following steps:

[0070] In step 701 , the wire cutter 103 is caused to cut the wire 101 into a first wire segment 110 outside the wire channel 105 and a second wire segment 111 at least partially located inside the wire channel 105 .

[0071] In step 702, the print head 107 and the printing platform 109 are translated relative to each other so that the print head 107 is positioned above the refill area.

[0072] In step 703 , the extruder 102 feeds the first strand segment 110 into the strand channel 105 via the first end 104 of the strand channel 105 , so that the second strand segment 111 is pushed by the first strand segment 110 toward the second end 108 of the strand channel 105 to a position beyond the seam 106 .

[0073] In step 704 , the extruder 102 is caused to withdraw the first strand segment 110 out of the strand channel 105 .

[0074] In step 705 , the extruder 102 is caused to feed the replacement strand into the strand channel 105 via the first end 104 of the strand channel 105 , so that the second strand segment 111 is pushed out of the strand channel 105 via the second end 108 of the strand channel 105 by the replacement strand.

[0075] Through step 701 to step 704, the 3D printer has completed the material withdrawal operation, but the second strand segment 111 is still in the strand channel 105. At this time, the material replacement operation can be performed, that is, step 705 is performed to make the extruder 102 feed the replacement strand into the strand channel 105, so that the second strand segment 111 is pushed out of the strand channel 105 by the replacement strand.

[0076] In one embodiment, it is observed whether the color of the wire material flowing out of the print head 107 is single and stable. If the color of the wire material flowing out is single and stable, then the 3D printer 100 has completed the operation of replacing the wire material.

[0077] Figure 8 A flowchart of a method 800 for a 3D printer according to another exemplary embodiment of the present disclosure is shown. The method 800 may include the following steps:

[0078] In step 801 , the extruder 102 is caused to withdraw the strand 101 by a predetermined length in a direction away from the second end 108 of the strand channel 105 .

[0079] According to some embodiments, the 3D printer 100 needs to terminate the printing operation first in order to perform the material change operation. At this time, a long portion of the wire 101 is located in the wire channel 105. In order to reduce the waste of the wire 101 that has not yet become molten, it is first necessary to withdraw a predetermined length through the extruder 102, that is, to perform step 801 first.

[0080] In one embodiment, the extruder is retracted a predetermined length, depending on how much length of the strand has not yet become molten.

[0081] In one embodiment, the extruder retracts to a predetermined length, which depends on a value set by the user before the 3D printer performs a material changing operation.

[0082] Then, steps 802 to 806 are performed. Steps 802 to 806 can be the same as those described above. Figure 7 The described steps 701 to 705 are the same and will not be repeated for the sake of brevity.

[0083] According to an embodiment of the present disclosure, a non-transitory computer-readable storage medium is further provided, on which instructions are stored, wherein when the instructions are executed by a processor, the steps of any method in any embodiment of the present disclosure are implemented.

[0084] According to an embodiment of the present disclosure, a computer program product is further provided, comprising instructions, wherein when the instructions are executed by a processor, the steps of any method in any embodiment of the present disclosure are implemented.

[0085] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in this disclosure can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0086] It should be understood that in this specification, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships or dimensions that are based on the orientations or positional relationships or dimensions shown in the accompanying drawings, and these terms are used only for the convenience of description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present disclosure.

[0087] In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", "third" may explicitly or implicitly include one or more of the feature. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0088] In the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0089] In the present disclosure, unless otherwise expressly specified and limited, a first feature being “above” or “below” a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being “above”, “above”, and “above” a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0090] This specification provides many different embodiments or examples that can be used to implement the present disclosure. It should be understood that these different embodiments or examples are purely exemplary and are not intended to limit the scope of protection of the present disclosure in any way. Those skilled in the art can conceive of various changes or replacements based on the disclosure of the present specification, which should all be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection defined by the attached claims.

Claims

1. A method for a 3D printer, wherein: The 3D printer comprises: a print head, defining a wire channel for passing a wire, the wire channel comprising a first end and a second end opposite to the first end, the wire to be melted at the second end, the wire channel being provided with a seam resulting from the joining of different components of the print head; an extruder configured to feed the wire into the wire channel via the first end and extrude the wire via the second end; and a wire cutter arranged between the extruder and the print head, the method comprising: The wire cutter cuts the wire into a first wire segment outside the wire channel and a second wire segment at least partially located in the wire channel; the second wire segment partially exceeds the first end of the wire channel; wherein the second wire segment below the wire cutter is a continuous wire segment; The extruder feeds the first strand segment into the strand channel via the first end of the strand channel, so that the second strand segment is pushed by the first strand segment toward the second end of the strand channel to a position beyond the joint; and the second strand segment is in direct contact with the first strand segment during the process of being pushed by the first strand segment; and The extruder is caused to draw the first strand segment back out of the strand channel.

2. The method of claim 1, wherein: Causing the wire cutter to cut the wire into a first wire segment and a second wire segment comprises: Moving the wire cutter from an initial position to a working position to cut the wire; While maintaining the strand cutter in the working position, causing the extruder to withdraw the strand in a direction away from the second end of the strand channel to ensure that the strand is cut into the first strand segment and the second strand segment; and The wire cutter is returned from the working position to the initial position.

3. The method of claim 1, wherein: Causing the wire cutter to cut the wire into a first wire segment and a second wire segment comprises: Move the wire cutter back and forth a predetermined number of times between an initial position and a working position for cutting the wire to ensure that the wire is cut into the first wire segment and the second wire segment; and The wire cutter is returned from the working position to the initial position.

4. The method of claim 1, wherein: The 3D printer further comprises a printing platform, the printing platform comprising a material change area for switching line materials, and wherein the print head and the printing platform are arranged to be translatable relative to each other, and the method further comprises: Prior to causing the extruder to feed the first strand segment into the strand channel through the first end of the strand channel, the print head and the printing platform are translated relative to each other such that the print head is positioned above the refill area.

5. The method of claim 1, wherein: The 3D printer further comprises a printing platform, the printing platform comprising a material change area for switching line materials, and wherein the print head and the printing platform are arranged to be translatable relative to each other, and the method further comprises: After the wire cutter cuts the wire into the first wire segment and the second wire segment, and before the extruder feeds the first wire segment into the wire channel through the first end of the wire channel, the print head and the printing platform are translated relative to each other so that the print head is positioned above the material changing area.

6. The method according to claim 4 or 5, further comprising: After causing the extruder to draw the first strand segment back out of the strand channel, causing the extruder to feed replacement strand into the strand channel through the first end of the strand channel so that the second strand segment is pushed out of the strand channel through the second end of the strand channel by the replacement strand.

7. The method according to any one of claims 1 to 5, further comprising: Before causing the strand cutter to cut the strand into the first strand segment and the second strand segment, causing the extruder to withdraw the strand by a predetermined length in a direction away from the second end of the strand channel.

8. A 3D printer, comprising: A print head, defining a wire channel for passing a wire, the wire channel comprising a first end and a second end opposite to the first end, the wire to be melted at the second end, the wire channel being provided with a seam resulting from the joining of different components of the print head; an extruder configured to feed the strand into the strand channel via the first end and extrude the strand via the second end; A wire cutter disposed between the extruder and the print head; as well as A processor configured to execute instructions to implement the method according to any one of claims 1 to 7.

9. A non-transitory computer-readable storage medium having instructions stored thereon, wherein: When the instructions are executed by the processor of the 3D printer according to claim 8, the method according to any one of claims 1 to 7 is implemented.

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