Printing head and 3D printing equipment

Abstract

The utility model provides a printing head and 3D printing equipment, and relates to the field of 3D printing. The printhead includes: a showerhead; and the material guiding channel is connected with the spray head, the material guiding channel is provided with a material breaking structure, and the material breaking structure is configured to generate counter-acting force on the consumable materials returning back in the material guiding channel.

Description

Technical Field

[0001] This utility model relates to the field of 3D printing, and in particular to a print head and a 3D printing device. Background Technology

[0002] Currently, when printing multi-color FDM (Fused Deposition Modeling) printers, the main method for switching color filaments during printing is to cut the filament in a single channel using a cutting mechanism, causing the filament to exit the single channel, and then extruding any remaining filament from the nozzle using a reflow mechanism. This method requires the printer to have an additional cutting mechanism and signal control for that mechanism, which is costly and time-consuming. Utility Model Content

[0003] In view of this, the present invention provides a print head and a 3D printing device, which enables the consumable to be quickly broken by the reaction force of the material breaking structure during the retraction process, thereby reducing equipment costs and increasing the material breaking speed.

[0004] In a first aspect, embodiments of the present invention provide a printhead, comprising:

[0005] spray nozzle;

[0006] A material guide channel is connected to the nozzle. The material guide channel is provided with a material cut-off structure, which is configured to generate a reaction force on the consumable material retracting within the material guide channel.

[0007] The printhead described in the embodiments of this application may also have the following additional technical features:

[0008] In the above technical solution, optionally, the material cutting structure is configured to cause the inner diameter of at least one section of the material guiding channel to decrease in the direction of material retraction, so as to generate a reaction force on the retracting consumable.

[0009] The cross-sectional area of ​​the consumable is greater than or equal to eight times the cross-sectional area of ​​the nozzle.

[0010] In any of the above technical solutions, optionally, the material guiding channel includes a throat section, which is conductively connected to the nozzle;

[0011] The material cutting structure is located in the throat section.

[0012] In any of the above technical solutions, optionally, the throat section includes a heat dissipation section and a melting section that are connected in communication, the melting section being conductively connected to the nozzle; the inner diameter of the heat dissipation section is less than or equal to the inner diameter of the melting section;

[0013] The material cutting structure is disposed in the melting section, or between the heat dissipation section and the melting section.

[0014] Optionally, in any of the above technical solutions, when the material cutting structure is disposed in the melting section, the material cutting structure is disposed within the melting section and close to the heat dissipation section.

[0015] In any of the above technical solutions, optionally, the material breaking structure is a concave structure;

[0016] The concave structure is arranged circumferentially along the inner wall of the molten section, or is disposed between the heat dissipation section and the molten section.

[0017] In any of the above technical solutions, optionally, the inner diameter of the concave structure gradually decreases or gradually increases in the retraction direction of the consumable, or the inner diameter of the concave structure first increases and then decreases in the retraction direction of the consumable.

[0018] Optionally, in any of the above technical solutions, the material guiding channel further includes at least two feeding channels respectively connected to the throat section;

[0019] The feeding channel includes a return position, and the consumable is returned to the return position corresponding to the feeding channel.

[0020] Optionally, in any of the above technical solutions, the print head further includes:

[0021] A heating assembly disposed on the outer periphery of at least a portion of the melting section and at least a portion of the nozzle;

[0022] The printhead also includes:

[0023] A heat dissipation assembly disposed on the outer periphery of at least a portion of the heat dissipation section.

[0024] Secondly, this utility model embodiment provides a 3D printing device, including: a print head as described in the first aspect.

[0025] In this embodiment of the invention, the feed channel of the printhead is provided with a feed-breaking structure, which is configured to generate a reaction force on the retracting filament within the feed channel. During the retraction of the filament, the reaction force exerted on the filament by the feed-breaking structure in the feed channel causes the filament to break during retraction. This application eliminates the need for an additional cutting mechanism to cut the filament via control signals, resulting in lower costs and faster breakage of the filament, thus improving the feed-breaking speed.

[0026] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more obvious and understandable, specific embodiments of this utility model are given below. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0028] Figure 1 One of the schematic diagrams of the printhead structure according to an embodiment of the present invention is shown;

[0029] Figure 2 A second schematic diagram of the print head structure according to an embodiment of the present invention is shown;

[0030] Figure 3 The third schematic diagram of the print head structure according to an embodiment of the present invention is shown;

[0031] Figure 4 The fourth schematic diagram of the printhead structure according to an embodiment of the present invention is shown;

[0032] Figure 5 The fifth schematic diagram shows the structure of the print head according to an embodiment of the present invention.

[0033] The correspondence between component names and reference numerals is as follows:

[0034] Printhead 100, nozzle 101, material cutting structure 102, heat dissipation section 103, melting section 104, heating component 105, extrusion wheel 106, material ejection position 107, heat dissipation component 108, melting chamber 109. Detailed Implementation

[0035] The technical solutions of the present utility model will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present utility model. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model are within the protection scope of the present utility model.

[0036] The terms "first," "second," etc., used in the specification and claims of this utility model are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this utility model can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, the first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0037] The print head and 3D printing equipment provided by the present invention will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0038] This utility model embodiment provides a printhead, such as Figure 1 As shown, the printhead 100 includes:

[0039] Nozzle 101;

[0040] A material guide channel is connected to the nozzle 101. The material guide channel is provided with a material cut-off structure 102, which is configured to generate a reaction force on the consumable material retracting within the material guide channel.

[0041] In this embodiment, the printhead 100 includes a feed channel and a nozzle 101 connected to the feed channel. The feed channel is provided with a feed-cutting structure 102, which is configured to generate a reaction force on the retracting consumable within the feed channel. The feed-cutting structure 102 can be part of the feed channel, i.e., integrally formed, or it can be assembled separately.

[0042] During printing, a retraction command is generated when there is a shortage of filament or a need to change filament. In response to the retraction command, the filament in the guide channel is controlled to retract along the guide channel, thus retracting the filament.

[0043] Specifically, the consumable is first controlled to retract a first preset distance at a first speed. In one embodiment, the value range of the first speed can be from 40mm / s to 300mm / s, with 40mm / s to 300mm / s including two endpoints, that is, the first speed can be either 40mm / s or 300mm / s. The first speed can also include 42mm / s, 43mm / s, 45mm / s, 47mm / s, 48mm / s, 49mm / s, 50mm / s, 180mm / s, 200mm / s, 220mm / s, 230mm / s, 250mm / s, 270mm / s, 290mm / s, etc. In related technologies, the typical filament retraction speed is less than 40 mm / s. If the filament retraction speed is greater than or equal to 40 mm / s, the filament will slip relative to the extrusion wheel 106. That is, if the filament's moving speed is greater than or equal to 40 mm / s, then the moving speed is the slippage speed. If the extrusion wheel 106 needs to control the filament to move 200 mm within 10 seconds, then controlling the filament to move at a speed of 20 mm / s for 10 seconds is sufficient. The distance moved will have virtually no error, or the error will be within the allowable range of printing accuracy. However, if the filament moves at a speed greater than or equal to 40 mm / s, the error in the distance moved will be larger. For example, if it moves at a speed of 100 mm / s for 2 seconds, theoretically the filament should move 200 mm, but due to the slippage between the filament and the extrusion wheel, the distance moved will be less than 200 mm, possibly as low as 150 mm, resulting in a larger movement error. In this embodiment, the retraction is performed at a speed far exceeding that of normal consumable retraction in the art, that is, at a slipping speed, meaning the first speed is greater than the non-slipping speed.

[0044] A material breaking structure 102 is installed in the material guiding channel. When the consumable retracts along the material guiding channel at a first speed, the material breaking structure 102 will generate a reaction force on the consumable. When the tensile force generated by the first speed and the reaction force generated by the material breaking structure are too large and exceed the tensile strength limit of the consumable, the consumable will break.

[0045] It should be noted that when the consumable retraction begins, the relative speed between the consumable and the extrusion wheel 106 is 0 mm / s. The friction between the consumable and the extrusion wheel 106 is relatively large, and no slippage occurs. Furthermore, there is a lag effect in the friction, meaning that even when the consumable moves at a very short slippage speed, slippage between the consumable and the extrusion wheel 106 will not occur. In this application, the first consumable retracts at a first speed for a first preset distance. Therefore, utilizing the initial friction and the lag effect, high-speed material retraction is achieved. Due to the high speed of this retraction process, the consumable can be broken. Rapidly breaking the consumable eliminates the problems of wire pulling and head clogging. The first preset distance can be less than the distance between the consumable and the extrusion wheel 106 to prevent slippage. It is understood that the first preset distance should allow the first consumable to be broken. If the first preset distance is too short, the first consumable cannot be broken, and subsequent re-entry of the second consumable may cause material blockage. Optionally, the first preset distance is greater than 3 mm. Optionally, the first preset distance can be equal to or greater than the distance between the consumable and the extrusion wheel 106 that prevents slippage, as long as the subsequent material ejection is performed at a speed lower than the slippage speed, i.e., a non-slippage speed, and as long as the ejection position of the end of the first consumable is within the allowable range. Optionally, the non-slippage speed is the speed at which the movement error is less than 0.5% when the extrusion wheel 106 controls the movement of the consumable.

[0046] In one embodiment, the print head 100 is applied to a 3D printing device, which also includes a feeding device connected to the print head 100. The feeding device provides the print head 100 with at least two different colors or materials of filament, and the nozzle 101 of the print head 100 ejects the filament to achieve model printing. It is understood that while the feeding device provides the print head 100 with at least two different colors or materials of filament, only one type of filament is provided at a time. The feeding device can be integrated into the print head 100 or can be separate from it.

[0047] In this embodiment, during material retraction, the consumable is first controlled to retract at high speed briefly. Due to the high speed of this retraction, the material breaking structure 102 located in the material guide channel exerts a reaction force on the consumable, causing it to break during the retraction. This application eliminates the need for an additional cutting mechanism to cut the consumable via control signals, resulting in lower costs and faster material breaking speed.

[0048] In one embodiment, the first velocity ranges from 50 cm / s to 160 mm / s, for example, the first velocity is 50 cm / s, 53 cm / s, 55 cm / s, 59 cm / s, 62 cm / s, 68 cm / s, 72 cm / s, 76 cm / s, 80 cm / s, 83 cm / s, 86 cm / s, 89 cm / s, 92 cm / s, 95 cm / s, 98 cm / s, 100 cm / s, 105 cm / s, 109 cm / s, 115 cm / s, 118 cm / s, 120 cm / s, 125 cm / s, 130 cm / s, 135 cm / s, 140 cm / s, 145 cm / s, 150 cm / s, 153 cm / s, 156 cm / s, or 160 mm / s. Further, the first velocity can range from 80 cm / s to 160 mm / s. Furthermore, the first speed ranges from 90cm / s to 140mm / s. By setting this appropriate speed range, on the one hand, a large enough speed is ensured to instantly break the filament, avoiding problems such as wire pulling and clogging; on the other hand, excessively fast retraction speed is avoided, which could lead to slippage between the filament and the extrusion wheel even during short-term, short-distance movement of the filament, allowing the filament to retract the required distance or to a suitable position.

[0049] The first preset distance is less than the distance the first consumable moves to retract to the ejection position. For example, after retracting the first preset distance, the cut end of the retracted portion of the consumable may be at the throat, but not yet at the ejection position. In one embodiment, the first preset distance ranges from 3mm to 13mm, for example, 3mm, 3.5mm, 5mm, 7mm, 8mm, 8.5mm, 9mm, 11mm, 12mm, or 13mm. Further, the first preset distance can range from 5mm to 9mm. This relatively short distance allows the first consumable to retract at a short, high speed, preventing slippage between the consumable and the extrusion wheel caused by a longer, high-speed retraction.

[0050] In one embodiment, the first preset distance is 7mm to 8.5mm. By setting this appropriate acceleration and retraction distance, on the one hand, it ensures that the filament is instantly broken through a high-speed, short retraction, avoiding problems such as wire pulling and head clogging; on the other hand, it avoids slippage between the filament and the extrusion wheel caused by a longer acceleration distance.

[0051] In one embodiment, if the consumable retracts a first preset distance at a first speed, the consumable is controlled to retract to the unloading position at a second speed, the second speed being less than the first speed, and the value range of the second speed being 0 mm / s to 35 mm / s.

[0052] The second speed at which the first consumable decelerates and retracts can be a fixed value or a variable range. The numerical range of the second speed is not limited, as long as slippage does not occur between the first consumable and the extrusion wheel. The second speed can be a non-slippage speed, meaning a speed that prevents slippage between the consumable and the extrusion wheel. When controlling the consumable to move a preset distance according to the non-slippage speed, the error between the actual distance moved and the preset distance is less than a preset threshold, which can be 0.5%. For example, in response to a material ejection command, if the extrusion wheel controls the consumable to move at a speed of 5 mm / s within 100 seconds, moving a total of 500 mm, and the actual distance moved by the consumable is within the range of 495-505 mm, then this speed is the non-slippage speed. The first speed is greater than the non-slippage speed, a larger speed. Using the first speed at the beginning of material ejection can achieve material breakage. After the first preset distance, the second speed is used to avoid slippage, ensuring the consumable stops accurately and stably at the ejection position.

[0053] Optionally, the second speed ranges from 0 mm / s to 35 mm / s, for example, retraction at speeds of 5 mm / s, 10 mm / s, 12 mm / s, 15 mm / s, 20 mm / s, 25 mm / s, 30 mm / s, or 35 mm / s. By decelerating the retraction to the unloading position, slippage between the consumable and the extrusion wheel can be avoided, achieving accurate control of the consumable retraction. It is understandable that with improvements to the extrusion wheel or different consumable materials, the slippage speed, or the critical value of the non-slippage speed, may change.

[0054] In this embodiment, after the consumable material is broken due to a brief high-speed retraction, it retracts to the ejection position at a lower speed, achieving a retraction process that is fast at first and then slows down. The high-speed retraction allows the consumable material to be quickly broken by the material-breaking structure, increasing the material-breaking speed. Furthermore, the fast-then-slow retraction process avoids slippage between the consumable material and the extrusion wheel caused by continuously retracting at high speed, thus accurately controlling the stopping point after the cut end of the retracted portion reaches the ejection position to complete the ejection process.

[0055] In one embodiment of this application, the material breaking structure 102 is configured to cause the inner diameter of at least one segment of the material guiding channel to decrease in the retraction direction of the consumable, so as to generate a reaction force on the retracting consumable.

[0056] In this embodiment, the material-cutting structure 102 can cause the inner diameter of at least one section of the material guide channel to decrease in the direction of material retraction. This decrease can be either gradual or abrupt. Consequently, during the material retraction along the material guide channel, a reaction force is generated on the material. If the tensile force generated by the initial velocity and the reaction force generated by the material-cutting structure exceed the tensile strength limit of the material, the material will break.

[0057] During material return, the consumable material in the guide channel is accelerated back. When a large speed is reached, the consumable material is instantly broken by the reaction force of the material breaking structure, achieving the effect of no wire pulling and no head blockage.

[0058] In one embodiment of this application, the cross-sectional area of ​​the consumable is greater than or equal to four times the cross-sectional area of ​​the nozzle.

[0059] In one embodiment of this application, the material guiding channel includes a throat section, which is conductively connected to the nozzle; the material cutting structure is disposed in the throat section.

[0060] In one embodiment of this application, the throat includes a heat dissipation section 103 and a melting section 104 that are connected in communication, the melting section 104 being conductively connected to the nozzle 101; the inner diameter of the heat dissipation section 103 is less than or equal to the inner diameter of the melting section 104;

[0061] The material breaking structure 102 is disposed in the melting section 104, or disposed between the heat dissipation section 103 and the melting section 104.

[0062] In this embodiment, such as Figures 1 to 5 As shown, the throat section includes a connected heat dissipation section 103 and a melting section 104, with the melting section 104 closer to the nozzle 101 than the heat dissipation section 103. The consumable material in the melting section 104 of the throat section is in a molten or semi-molten state. The hardness of the consumable material in its molten or semi-molten state is less than its hardness at room temperature. It can be understood that the consumable material is also in a molten state within the nozzle 101.

[0063] The material cutting structure 102 is disposed in the melting section 104, or between the heat dissipation section 103 and the melting section 104. Figures 1 to 5 The case where the material cutting structure 102 is located between the heat dissipation section 103 and the melting section 104.

[0064] In one embodiment of this application, the printhead further includes a heating assembly 105 disposed on the outer periphery of at least a portion of the melting section 104 and at least a portion of the nozzle 101.

[0065] In this embodiment, the printhead 100 further includes a heating assembly 105 disposed on the outer periphery of at least a portion of the melting section 104 and at least a portion of the printhead 101. By controlling the heating assembly 105 to heat, the temperature of the melting section 104 and the printhead 101 increases, and the consumable material within the melting section 104 changes from a solid state to a molten state. That is, the hardness of the consumable material in the melting section is less than the hardness of the consumable material not heated by the melting section. In one embodiment, the heating assembly 105 includes a melting cavity 109 located between the throat and the printhead 101, and the consumable material is also in a molten state within the melting cavity 109.

[0066] During printing, the heating component 105 is turned on to achieve heating. The part of the melting section 104 closer to the printhead 101 has a higher temperature and is called the fully molten part. The part closer to the heat dissipation section 103 has a lower temperature. Some consumables are in a semi-molten state and this part is called the semi-molten part. The degree of melting of the consumables in the fully molten part is higher than that in the semi-molten part. The consumables in the fully molten part are in a fully molten state, and some consumables in the semi-molten part are in a semi-molten state.

[0067] In this embodiment, the inner diameter of the heat dissipation section 103 can be smaller than or equal to the inner diameter of the melting section 104. When the inner diameter of the heat dissipation section 103 is smaller than that of the melting section 104, a material-cutting structure 102 is provided between the heat dissipation section 103 and the melting section 104 to facilitate the transition, resulting in a decrease in the inner diameter of the entire material guiding channel from the nozzle 101 to the feeding device. When the inner diameter of the heat dissipation section 103 is equal to that of the melting section 104, the material-cutting structure 102 is used to ensure that the inner diameter of the entire material guiding channel decreases from the nozzle 101 to the feeding device.

[0068] In one embodiment of this application, when the material breaking structure 102 is disposed in the melting section 104, the material breaking structure 102 is located within the melting section 104 and close to the heat dissipation section 103. This can be understood as the material breaking structure 102 being disposed in the semi-molten part or within 1 mm of the fully molten part. When the consumable material retracts, it will try to break the semi-molten consumable material rather than the fully molten consumable material, thereby reducing the problems of consumable material stringing and clogging.

[0069] Furthermore, in the methods of related technologies, the cutting mechanism cuts the consumable near the extrusion wheel, a considerable distance from the nozzle, resulting in a longer residual consumable and greater material waste during material replacement. In contrast, in this embodiment, the material-cutting structure 102 is located on the throat, closer to the nozzle 101 than the cutting mechanism in related technologies. This results in a shorter residual consumable after material removal, leading to greater material savings during material replacement.

[0070] In one embodiment of this application, the material breaking structure 102 is a concave structure;

[0071] The concave structure is arranged circumferentially along the inner wall of the molten section 104, or is arranged between the heat dissipation section 103 and the molten section 104.

[0072] In this embodiment, the material-cutting structure 102 is a concave structure, which is arranged circumferentially along the inner wall of the melting section 104, or disposed between the heat dissipation section 103 and the melting section 104. Exemplarily, the material-cutting structure 102 can be as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown, the shape of the material breaking structure 102 is not specifically limited, as long as it can make the inner diameter of at least one section of the material guiding channel shrink in the direction of material retraction.

[0073] In one embodiment of this application, the inner diameter of the concave structure gradually decreases or gradually increases in the retraction direction of the consumable, or the inner diameter of the concave structure first increases and then decreases in the retraction direction of the consumable.

[0074] In this embodiment, the maximum inner diameter of the material breaking structure 102 can be greater than the inner diameter of the heat dissipation section 103, and the minimum inner diameter of the material breaking structure 102 can be greater than or equal to the inner diameter of the heat dissipation section 103. For example... Figure 2 As shown, the inner diameter of the material cutting structure 102 can gradually decrease in the direction of material retraction; as Figure 3 As shown, the inner diameter of the material cutting structure 102 can also gradually increase in the direction of material retraction; as Figure 5 As shown, the inner diameter of the material cutting structure 102 first increases and then decreases in the direction of material retraction; as Figure 4 As shown, the inner diameter of the material breaking structure 102 remains unchanged, and the inner diameter at each position is larger than the inner diameter of the heat dissipation section 103.

[0075] The material breaking structure 102 causes the inner diameter of at least one section of the material guiding channel to shrink in the direction of material retraction, thereby generating a reaction force on the retracting material and causing it to break during the retraction process.

[0076] In one embodiment of this application, the material guiding channel further includes at least two feeding channels respectively communicating with the throat portion;

[0077] The feeding channel includes a return position, and the consumable is returned to the return position corresponding to the feeding channel.

[0078] In this embodiment, the material guide channel further includes at least two feed channels respectively connected to the throat section, with different feed channels used to convey consumables of different colors or materials. The feed inlets of the feed channels are connected to the feeding device of the 3D printing equipment, and the discharge outlets of the feed channels are connected to the feed inlet of the throat section, with the discharge outlet of the throat section connected to the printhead 101. The printhead 100 also includes an extrusion wheel 106, which is used for conveying and retracting consumables.

[0079] like Figure 1 As shown, the feeding channel includes a return position 107, which refers to the end position of the consumable's return. The consumable will eventually return to the return position 107 of its corresponding feeding channel.

[0080] In one embodiment of this application, such as Figure 1 As shown, the printhead 100 further includes a heat dissipation assembly 108, which is disposed on the outer periphery of at least a portion of the heat dissipation section 103.

[0081] In this embodiment, the printhead 100 includes a heat dissipation component 108 disposed on the outer periphery of at least a portion of the heat dissipation section 103, so that the heat dissipation section 103 dissipates heat, accelerates the cooling of the consumables, and prevents the melted portion of the consumables from being too long and affecting printing.

[0082] This utility model embodiment also provides a 3D printing device, including: a print head as described in the first aspect.

[0083] 3D printing equipment can be monochrome or multicolor 3D printers. 3D printing equipment also includes a feeding device connected to the print head, which provides at least two different colors or materials of filament to the print head. The nozzle of the print head then ejects the filament to achieve model printing.

[0084] This utility model also provides the following embodiments:

[0085] Example 1: A printhead, comprising:

[0086] spray nozzle;

[0087] A material guide channel is connected to the nozzle. The material guide channel is provided with a material cut-off structure, which is configured to generate a reaction force on the consumable material retracting within the material guide channel.

[0088] Example 2, based on Example 1, the material cutting structure is configured to cause the inner diameter of at least one section of the material guiding channel to decrease in the direction of material retraction, so as to generate a reaction force on the retracting consumable.

[0089] The cross-sectional area of ​​the consumable is greater than or equal to four times the cross-sectional area of ​​the nozzle.

[0090] Example 3, based on Example 1, the material guiding channel includes a throat section, which is conductively connected to the nozzle;

[0091] The material cutting structure is located in the throat section.

[0092] Example 4, based on Example 3, the throat section includes a heat dissipation section and a melting section that are connected in communication, and the melting section is conductively connected to the nozzle; the inner diameter of the heat dissipation section is less than or equal to the inner diameter of the melting section;

[0093] The material cutting structure is disposed in the melting section, or between the heat dissipation section and the melting section.

[0094] Example 5: Based on Example 3, when the material cutting structure is set in the melting section, the material cutting structure is located within the melting section and close to the heat dissipation section.

[0095] Example 6: Based on Example 3, the material breaking structure is a concave structure;

[0096] The concave structure is arranged circumferentially along the inner wall of the molten section, or is disposed between the heat dissipation section and the molten section.

[0097] Example 7: Based on Example 6, the inner diameter of the concave structure gradually decreases or gradually increases in the retraction direction of the consumable, or the inner diameter of the concave structure first increases and then decreases in the retraction direction of the consumable.

[0098] Example 8, based on Example 3, further includes at least two feed channels that are respectively connected to the throat section;

[0099] The feeding channel includes a return position, and the consumable is returned to the return position corresponding to the feeding channel.

[0100] Example 9, based on any one of Examples 3 to 8, further includes:

[0101] A heating assembly disposed on the outer periphery of at least a portion of the melting section and at least a portion of the nozzle;

[0102] The printhead also includes:

[0103] A heat dissipation assembly disposed on the outer periphery of at least a portion of the heat dissipation section.

[0104] This utility model has been described through the above embodiments. However, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit the utility model to the described embodiments. Furthermore, those skilled in the art will understand that this utility model is not limited to the above embodiments, and many more variations and modifications can be made based on the teachings of this utility model, all of which fall within the scope of protection claimed by this utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A printhead, characterized by, The printing head comprises: a nozzle; a material guiding channel connected with the nozzle, the material guiding channel being provided with a material breaking structure configured to generate a reaction force on the backflowing consumable in the material guiding channel.

2. The printing head according to claim 1, wherein the material breaking structure is configured to cause the inner diameter of at least a section of the material guiding channel to decrease in the backflow direction of the consumable, so as to generate a reaction force on the backflowing consumable; the cross-sectional area of the consumable is greater than or equal to 4 times the cross-sectional area of the nozzle.

3. The printing head according to claim 1, wherein the material guiding channel comprises a throat section connected with the nozzle in a conductive manner; the material breaking structure is arranged in the throat section.

4. The printing head according to claim 3, wherein the throat section comprises a heat dissipation section and a melting section connected in a conductive manner, the melting section being connected with the nozzle in a conductive manner, the inner diameter of the heat dissipation section being less than or equal to the inner diameter of the melting section; the material breaking structure is arranged in the melting section or between the heat dissipation section and the melting section.

5. The printing head according to claim 4, wherein when the material breaking structure is arranged in the melting section, the material breaking structure is arranged in the melting section and close to the heat dissipation section.

6. The printing head according to claim 4, wherein the material breaking structure is a concave structure; the concave structure is arranged along the inner wall of the melting section in a circumferential direction or between the heat dissipation section and the melting section.

7. The printing head according to claim 6, wherein the inner diameter of the concave structure gradually decreases or gradually increases in the backflow direction of the consumable, or the inner diameter of the concave structure first increases and then decreases in the backflow direction of the consumable.

8. The printing head according to claim 3, wherein the material guiding channel further comprises at least two material inlet channels connected with the throat section in a conductive manner, respectively; the material inlet channels comprise material backflow positions, and the consumable backflows to the material backflow positions corresponding to the material inlet channels.

9. The printhead of claim 4, wherein, The printing head further comprises: a heating assembly arranged at least partially in the outer periphery of the melting section and at least partially in the outer periphery of the nozzle; The printing head further comprises: a heat dissipation assembly arranged at least partially in the outer periphery of the heat dissipation section.

10. A 3D printing device, characterized by The printing head according to any one of claims 1 to 9. ​

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