Powder spreading apparatus, 3D printing device, and production line

Abstract

A powder spreading apparatus, comprising a powder bin body (110), a powder blocking assembly (120), and a powder discharge shaft (130). The powder blocking assembly (120) is arranged on a side of the powder bin body (110), the powder bin body (110) and the powder blocking assembly (120) constitute a powder discharge bin, a powder discharge opening is formed at the bottom of the powder discharge bin, and the powder discharge shaft (130) is rotatably disposed at the powder discharge opening and is arranged to extend along the length direction of the powder discharge opening. The bottom of the powder blocking assembly (120) is in contact with the powder discharge shaft (130). The powder discharge shaft (130) is provided with a plurality of annular powder recesses (131) spaced apart along the length direction thereof. When the powder discharge shaft (130) rotates in a first direction, powder in the powder discharge bin is spread on a powder spreading surface by means of the annular powder recesses (131). The present invention also relates to a 3D printing device and a 3D printing production line, and can solve product quality problems caused by a poor powder spreading effect of existing 3D printing devices.

Description

Powder spreading device, 3D printing equipment and production line Technical Field

[0001] The present invention relates to the field of 3D printing technology, and in particular to a powder spreading device, 3D printing equipment and a production line. Background Art

[0002] In 3D printing technology, granular or powdered materials are usually added to the powder spreader first. The powder spreader steps forward to spread the powder material on the powder spreading surface, and then the powder is flattened with a scraper or other tool. Finally, the print head selectively sprays the bonding material onto the spread powder according to the cross-sectional shape of the designed product prototype, so that the powder material bonds together to form the prototype cross-section of the product. After one layer is printed, the workbench descends to the height of a cross-section, and the above steps are repeated until the prototype printing is completed.

[0003] In the 3D printing process of new ceramic materials, many types of ceramic materials are involved. Currently, the commonly used new ceramic materials include silicon carbide ceramics, porous silicon nitride ceramics, alumina ceramics and tricalcium phosphate ceramics. The above-mentioned ceramic powder materials are easily affected by humidity and produce agglomeration, which leads to poor powder feeding, affects the flatness of the powder laying surface, and directly affects the quality of the printed product. Technical issues

[0004] Based on this, it is necessary to provide a powder spreading device, 3D printing equipment and production line to address product quality problems caused by the uneven powder spreading surface of existing 3D printing equipment. Technical Solutions

[0005] In order to solve the above problems, the present invention adopts the following technical solutions:

[0006] In the first aspect, an embodiment of the present invention discloses a powder spreading device, comprising a powder bin main body, a powder blocking assembly and a lower powder shaft, wherein the powder blocking assembly is arranged on one side of the powder bin main body, and the powder bin main body and the powder blocking assembly constitute a lower powder bin, and a lower powder opening is formed at the bottom of the lower powder bin, and the lower powder shaft is rotatably arranged at the lower powder opening and extends along the length direction of the lower powder opening. The bottom of the powder blocking assembly is in contact with the lower powder shaft, and the lower powder shaft is provided with a plurality of annular powder grooves spaced apart along its length direction. When the lower powder shaft rotates along the first direction, the powder in the lower powder bin is spread on the powder spreading surface through the annular powder grooves.

[0007] In a second aspect, an embodiment of the present invention discloses a 3D printing device, comprising the powder spreading device described above.

[0008] In a third aspect, an embodiment of the present invention discloses a 3D printing device, comprising a frame, a powder spreading device, a printing device, and a motion device, wherein the printing device and the powder spreading device are both movably disposed on the frame, and the printing device and the powder spreading device are both drivably connected to the motion device. The motion device simultaneously drives the powder spreading device and the printing device to move along different motion paths in an interlaced manner, so that the powder spreading device and the printing device can simultaneously spread powder and print. The powder spreading device comprises a powder hopper body, a powder blocking assembly, and a lower powder shaft. The powder blocking assembly is disposed on one side of the powder hopper body. The powder hopper body and the powder blocking assembly constitute a lower powder hopper. A lower powder opening is formed at the bottom of the lower powder hopper. The lower powder shaft is rotatably disposed at the lower powder opening and extends along the length direction of the lower powder opening. The bottom of the powder blocking assembly contacts the lower powder shaft. The lower powder shaft is provided with a plurality of annular powder grooves spaced apart along its length direction. When the lower powder shaft rotates in a first direction, the powder in the lower powder hopper is spread on the powder spreading surface through the annular powder grooves.

[0009] In a fourth aspect, an embodiment of the present invention discloses a 3D printing production line, comprising the 3D printing device described above. Beneficial effects

[0010] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0011] In the powder spreading device disclosed in the embodiment of the present invention, the contact cooperation between the powder blocking component and the lower powder shaft is used so that the powder in the lower powder bin can only be transported to the powder spreading surface through multiple annular powder grooves through the rotation of the lower powder shaft. That is, the amount of powder transported depends on the size of the annular powder groove, so that the multiple annular powder grooves play a role in quantitative powder discharging to ensure the flatness of the powder spreading surface and improve product quality. At the same time, through the rotation of the lower powder shaft and the quantitative powder discharging of the annular powder grooves, it can prevent the powder material from being easily affected by the environment and causing agglomeration, resulting in poor powder discharging and other problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG1 is a schematic structural diagram of a powder spreading device disclosed in an embodiment of the present invention;

[0013] FIG2 is a schematic structural diagram of FIG1 from another perspective;

[0014] FIG3 is a partial enlarged schematic diagram of FIG2;

[0015] FIG4 is another partially enlarged schematic diagram of FIG2 ;

[0016] FIG5 is a schematic structural diagram of a powder spreading device disclosed in another embodiment of the present invention;

[0017] FIG6 is a partial enlarged schematic diagram of FIG5;

[0018] FIG7 is a schematic diagram of a partial structure of a material distribution mechanism disclosed in an embodiment of the present invention;

[0019] FIG8 is a schematic structural diagram of a 3D printing device in motion according to an embodiment of the present invention;

[0020] FIG9 is a schematic structural diagram of a 3D printing production line disclosed in an embodiment of the present invention;

[0021] FIG10 is a schematic structural diagram of a 3D printing production line disclosed in another embodiment of the present invention;

[0022] Description of reference numerals:

[0023] 100-powder spreading device, 110-powder bin main body, 120-powder blocking assembly, 121-installation part, 122-contact part, 130-lower powder shaft, 131-annular powder trough, 132-shadow part, 140-connecting baffle, 150-powder spreading part, 151-powder spreading channel, 160-scraper, 170-material equalizing mechanism, 171-toothed part, 180-powder scraping mechanism, 181-protrusion, 190-first arrow, 200-frame, 300-printing device, 310-second arrow, 400-3D printing equipment, 500-centralized sand mixing equipment, 600-centralized liquid supply equipment, 710-sand cleaning station, 720-drying station, 730-workpiece storage station, 740-conveyance mechanism. Best Mode for Carrying Out the Invention

[0024] An embodiment of the present invention discloses a powder spreading device, comprising a powder bin main body, a powder blocking assembly and a lower powder shaft, wherein the powder blocking assembly is arranged on one side of the powder bin main body, the powder bin main body and the powder blocking assembly constitute a lower powder bin, a lower powder opening is formed at the bottom of the lower powder bin, the lower powder shaft is rotatably arranged at the lower powder opening, and is extended along the length direction of the lower powder opening, the bottom of the powder blocking assembly is in contact with the lower powder shaft, and the lower powder shaft is provided with a plurality of annular powder grooves spaced apart along its length direction, and when the lower powder shaft rotates along a first direction, the powder in the lower powder bin is spread on the powder spreading surface through the annular powder grooves. Modes for Carrying Out the Invention

[0025] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0026] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be an element centered thereon. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an element centered thereon. The terms "vertical," "horizontal," "left," "right," "top," "bottom," "bottom end," "top end," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] As shown in Figures 1 to 7, an embodiment of the present invention discloses a powder spreading device. The disclosed powder spreading device is applied to a 3D printing device, so that the powder material is evenly spread on the powder spreading surface by moving to realize the powder spreading operation. This powder spreading device specifically includes a powder bin main body 110, a powder blocking assembly 120 and a lower powder shaft 130.

[0029] The powder bin body 110 is the main structure of the lower powder bin. Usually, the powder bin body 110 is fixedly installed on the device body of the powder spreading device. In an embodiment of the present invention, the powder blocking assembly 120 is arranged on one side of the powder bin body 110. The powder bin body 110 and the powder blocking assembly 120 constitute the lower powder bin, that is, the powder blocking assembly 120 is equivalent to a side panel of the lower powder bin, and the lower powder bin is used to temporarily store powder.

[0030] A powder outlet is formed at the bottom of the lower powder bin, and a powder outlet shaft 130 is rotatably disposed at the powder outlet, extending along the length of the powder outlet (see Figure 1). The powder outlet can be a strip-shaped hole, and the powder outlet shaft 130 can be positioned above and extend along the length of the strip-shaped hole.

[0031] In the embodiment disclosed in the present invention, the bottom of the powder blocking assembly 120 is in contact with the lower powder shaft 130, and the lower powder shaft 130 is provided with a plurality of annular powder grooves 131 spaced apart along its length direction. In this case, the bottom (one end) of the powder blocking assembly 120 is in contact with the top of the annular powder groove 131, which is equivalent to closing a portion of the annular powder groove 131 through the top (end) portion of the powder blocking assembly 120, and the portion closed by the plurality of annular powder grooves 131 extends along the length direction of the lower powder shaft 130. It can also be said that the portion closed by the plurality of annular powder grooves 131 extends along the length direction of the lower powder port.

[0032] Please refer to Figure 4 for details. During operation, the powder lowering shaft 130 rotates so that the powder can flow out through the channel formed by the powder blocking assembly 120 and the annular powder groove 131, as indicated by the shaded portion 132 in Figure 4, to achieve the effect of quantitative powder lowering.

[0033] When the lower powder shaft 130 rotates in the first direction (that is, along the axis of the lower powder shaft), the powder in the lower powder bin is carried and transported through the annular powder groove 131 and then laid on the powder laying surface. In the specific working process, please refer to Figure 2. The first direction is counterclockwise. When powder needs to be lowered, part of the lower powder shaft is placed in the powder. The lower powder shaft 130 rotates in the counterclockwise direction, which can drive the powder contained in the annular powder groove 130 in the lower powder bin to rotate with the lower powder shaft. When the lower powder shaft 130 drives the powder to move to the position where the powder blocking component 120 is located, a part of the powder is blocked by the powder blocking component 120, and the other part of the powder in the annular powder groove 131 passes through the position where the powder blocking component 120 is located, and then gradually moves in the direction toward the powder laying surface through the rotation of the lower powder shaft 130, and is finally laid on the powder laying surface by the action of gravity.

[0034] From the above content, it can be seen that in the powder spreading device disclosed in the embodiment of the present invention, the contact and cooperation between the powder blocking assembly 120 and the lower powder shaft 130 is used so that the powder in the lower powder bin can only be transported to the powder spreading surface through multiple annular powder grooves 131 through the rotation of the lower powder shaft 130, that is, the amount of powder transported depends on the size of the annular powder grooves 131, so that the multiple annular powder grooves 131 play a role in quantitative powder discharging to ensure the flatness of the powder spreading surface and improve product quality; at the same time, through the rotation of the lower powder shaft 130 and the quantitative powder discharging of the annular powder grooves 131, it is possible to prevent the powder material from being easily affected by the environment and causing agglomeration, resulting in poor powder discharging, and thus can meet the powder spreading work of various materials that are easily affected by humidity and produce agglomeration, such as silicon carbide ceramics, porous silicon nitride ceramics, alumina ceramics and tricalcium phosphate ceramics.

[0035] At the same time, the above-mentioned powder spreading device is not only applicable to ceramic materials, but also to powder materials such as metal powder, quartz sand, silica sand, and gypsum.

[0036] Of course, in the embodiment disclosed in the present invention, the rotation speed of the lower powder shaft 130 can also be controlled to control the amount of powder dropped, so as to meet the powder spreading requirements of different working conditions. Furthermore, there can be a variety of arrangements and layouts of the multiple annular powder grooves 131. For example, the multiple annular powder grooves 131 can be evenly distributed in the length direction of the lower powder shaft 130 to ensure the uniformity of powder spreading at each position; at the same time, in the middle of the lower powder shaft 130 and in the direction extending along both sides, the distance between two adjacent annular powder grooves 131 can gradually increase to meet the uniform powder spreading requirements under special working conditions. There can also be a variety of arrangements and layouts of the multiple annular powder grooves 131, and the embodiment of the present invention does not limit this.

[0037] Furthermore, it should be noted that the center lines of the multiple annular powder grooves 131 can be perpendicular to the axis of the powder discharge shaft 130, and the multiple annular powder grooves 131 are all arranged in parallel to ensure the powder discharge effect.

[0038] In the embodiment disclosed in the present invention, the powder blocking assembly 120 may include a mounting portion 121 and a contact portion 122, the mounting portion 121 being detachably disposed on one side of the powder bin body 110, specifically, the mounting portion 121 being detachably disposed on one side of the powder bin body 110 by bonding, clamping, or bolting to constitute a part of the lower powder bin, and the contact portion 122 being detachably disposed at the bottom of the mounting portion 121, and the contact portion 122 may be in contact with the lower powder shaft 130. In this case, the mounting portion 121 can provide a mounting position for the contact portion 122, so that the contact effect with the lower powder shaft 130 can be achieved by simply adjusting the position of the contact portion 122. It can be seen from this that the above method is not only conducive to the assembly of the powder blocking assembly 120, but also facilitates the contact with the lower powder shaft 130.

[0039] At the same time, the contact portion 122 is detachably provided at the bottom of the mounting portion 121 , and the contact portion 122 can be replaced at any time, thereby improving practicality.

[0040] Furthermore, there can be multiple ways to detachably connect the contact portion 122 to the mounting portion 121. In an optional solution, a mounting groove can be provided at the bottom of the mounting portion 121, and the contact portion 122 can be connected to the mounting groove by bonding, snapping, magnetic connection or bolt connection to facilitate the detachable installation of the contact portion 122.

[0041] In the embodiment of the present invention, the specific shape of the contact portion 122 can be various. For example, the contact portion 122 can be a plate-like member, a cylindrical member such as a roller, or a structural member of other shapes, that is, any structural member capable of contacting the lower powder shaft 130 along its length, and is not limited to the above structures. Furthermore, the contact portion 122 can be a rigid member or a flexible member, and the embodiment of the present invention does not impose any restrictions on this.

[0042] In an optional embodiment, in order to ensure the contact effect with the lower powder shaft 130 and to further improve the service life of the lower powder shaft, the contact portion 122 can be a flexible part, preferably a wear-resistant flexible part. For example, the contact portion 122 can be a rubber part or the part where the outer surface of the contact portion contacts the lower powder shaft is coated with rubber. This method can not only ensure the contact effect between the contact portion 122 and the lower powder shaft 130, but also make the contact portion 122 in contact with the lower powder shaft 130 have less influence on the rotation effect of the lower powder shaft 130. Of course, the mounting portion 121 and the contact portion 122 can be an integrally molded part to improve molding efficiency; the mounting portion 121 and the contact portion 122 can also be molded in a multi-section splicing manner to ensure the straightness of the mounting portion 121 and the contact portion 122. The embodiment of the present invention does not impose any restrictions on this.

[0043] The powder spreading device disclosed in the embodiment of the present invention may also include a plurality of connecting baffles 140 of different sizes. The connecting baffles 140 can be used to connect the powder blocking assembly 120 and the powder bin body 110, that is, the connecting baffles 140 can be inserted between the powder blocking assembly 120 and the powder bin body 110 to connect the powder blocking assembly 120 and the powder bin body 110, and finally realize the molding of the lower powder bin, as shown in Figure 1. This connection method has a simple structure and operation method, and can quickly realize the assembly of the powder blocking assembly 120 and the powder bin body 110. Specifically, the connecting baffle 140 can be connected to the powder blocking assembly 120 and the powder bin body 110 by bolt connection, or by snap connection and other methods, and the embodiment of the present invention does not impose any restrictions on this.

[0044] Furthermore, the connecting baffle 140 may include a plurality of different sizes, and the powder blocking assembly 120 may contact different positions on the lower powder shaft 130 through the connecting baffles 140 of different sizes. Specifically, when a connecting baffle 140 of one size is used to connect the powder blocking assembly 120 and the powder hopper body 110, the powder blocking assembly 120 may contact a first position of the lower powder shaft 130; when a connecting baffle 140 of another size is used to connect the powder blocking assembly 120 and the powder hopper body 110, the powder blocking assembly 120 may contact a second position of the lower powder shaft 130. The first position and the second position are spaced apart along the circumference of the lower powder shaft 130. In this case, the powder blocking assembly 120 may contact different positions on the lower powder shaft 130 by replacing the connecting baffles 140 of different sizes.

[0045] In the above case, by replacing the connecting baffles 140 of different sizes, the powder blocking assembly 120 can be made to contact different positions on the lower powder shaft 130, thereby meeting the powder laying requirements of materials with different particle sizes and different materials, so as to improve the practicality of the equipment. For example, when the fluidity of the material is poor, the powder blocking assembly 120 can be controlled to contact the position of the lower powder shaft 130 away from the powder bin body 110; when the fluidity of the material is good, the powder blocking assembly 120 can be controlled to contact the position of the lower powder shaft 130 close to the powder bin body 110, so that the lower powder shaft 130 can achieve a better conveying effect for materials with different fluidities. Specifically, according to the characteristics of the material, the powder blocking assembly 120 can be selected to contact different positions of the lower powder shaft 130 to meet the powder laying requirements of different materials.

[0046] Furthermore, when a connecting baffle 140 of one size is used to connect the powder blocking assembly 120 and the powder bin body 110, the number of connecting baffles 140 can be multiple, and the multiple connecting baffles can be spaced apart in the length direction of the powder blocking assembly 120 or the powder bin body 110 to ensure connection stability.

[0047] In another optional solution, the powder blocking assembly 120 can be rotatably arranged on one side of the powder bin body 110, and the powder blocking assembly 120 can contact different positions on the lower powder shaft 130 by rotation. This method can also meet the powder laying requirements of materials with different particle sizes and different materials, so as to improve the practicality of the equipment. For example, when the fluidity of the material is poor, the powder blocking assembly 120 can be controlled to contact the position of the lower powder shaft 130 away from the powder bin body 110; when the fluidity of the material is good, the powder blocking assembly 120 can be controlled to contact the position of the lower powder shaft 130 close to the powder bin body 110, so that the lower powder shaft 130 can achieve a better conveying effect for materials with different fluidities. Specifically, according to the characteristics of the material, the powder blocking assembly 120 can be selected to contact different positions of the lower powder shaft 130 to meet the powder laying requirements of different materials.

[0048] Furthermore, the top of the powder blocking assembly 120 can be rotatably arranged so that the bottom of the powder blocking assembly 120 rotates around its top to meet the powder discharge requirements of materials with different particle sizes and different materials. Of course, in this case, the powder blocking assembly 120 can include a mounting portion 121 and a contact portion 122, the mounting portion 121 being rotatably arranged on one side of the powder bin body 110, and the contact portion 122 being detachably arranged on the bottom of the mounting portion 121, and the contact portion 122 being able to contact the lower powder shaft 130, so that in order to meet the effect of being able to contact the lower powder shaft 130 at different positions, the contact portions 122 of different sizes can be replaced.

[0049] In the above case, not only can the powder blocking component 120 be in contact with different positions on the lower powder shaft 130 to meet the powder discharge requirements of materials with different particle sizes and different materials; the position of the powder blocking component 120 can also be changed to control the size of the lower sand bin to adapt to different equipment and working conditions.

[0050] In the embodiment of the present invention, the specific shape of the annular powder groove 131 can be various. Optionally, the opening of the annular powder groove 131 can gradually increase along the radial direction of the lower powder shaft 130, as shown in Figure 3 or Figure 6. That is, the cross-section of the annular powder groove 131 along the radial direction of the lower powder shaft 130 is a trapezoid with a small bottom and a large opening. The annular powder groove 131 of this structure can not only meet the powder discharge efficiency, but also has a good anti-sand sticking effect compared to other structures, and can better play the role of quantitative powder discharge. Furthermore, to better play the role of anti-sand sticking, the bottom corners of the annular powder groove 131 can be chamfered to ensure a better sand flow effect.

[0051] Of course, the cross section of the annular powder groove 131 along the radial direction of the lower powder shaft 130 can also be triangular, rectangular, semicircular, etc., and the embodiment of the present invention does not limit this.

[0052] In the embodiment disclosed in the present invention, the powder lowering shaft 130 may include a plurality of rollers, and the plurality of rollers may be connected in sequence, and each roller may be provided with an independent driving unit, which may be used to drive each roller to rotate. In this case, it is equivalent to dividing the powder lowering shaft 130 into multiple sections along its length direction, and each section has an independent driving unit, and then the corresponding rollers are driven to rotate by the driving unit, so that the rotation speeds of the plurality of rollers are adjustable. When a powder lowering shaft 130 of this structure is adopted, the powder spreading requirements under different working conditions can be met. For example, when a certain position along the length direction of the powder lowering shaft 130 produces a situation where powder is not spread smoothly, the powder spreading requirements of the position can be met by increasing the rotation of the roller at the position. In summary, this method can better play the role of quantitative powder lowering by adjusting the rotation speed of each roller.

[0053] In an optional embodiment, the lower powder shaft 130 may further include a central shaft, with multiple rollers sequentially mounted on the central shaft. Multiple drive units may be spaced apart on the central shaft, with each roller being drivably connected to a corresponding drive unit. This arrangement not only facilitates the overall assembly of the lower powder shaft 130, but also allows each roller to be independently driven.

[0054] Furthermore, each roller can be sequentially sleeved on the central shaft through bearings, a conductive ring can be provided in the middle position of the inner cavity of each roller, and metal contacts corresponding to each conductive ring can be provided on the roller; a coil can also be provided on the inner side of each roller, and permanent magnets corresponding to each coil can be provided in sections on the central shaft, and each metal contact can be connected to each cable respectively. The central shaft is axially provided with a channel for each cable to pass through, that is, each cable is connected to each metal contact after passing through the channel.

[0055] When the powder spreading device starts to step, the control unit controls each cable to be energized, and each metal contact and each conductive ring is energized. The rollers with coils are equivalent to rotors. After power is supplied, the rotor can rotate around the central axis, that is, each roller rotates around the central axis, thereby achieving the effect of driving each roller separately.

[0056] At the same time, a sensor can be provided at the position corresponding to each roller. When the amount of powder dropped at the position corresponding to a certain sensor needs to be adjusted, the rotational speed of the roller corresponding to the sensor needs to be adjusted. At this time, the control unit controls the output current of the cable corresponding to the roller to change and thus adjust the rotational speed of the roller. That is, a permanent magnet is set on the central axis and a coil is set on each roller. When the input current on each roller changes, the rotational speed of the roller will also change accordingly. In this way, the amount of powder dropped can be accurately controlled in sections by controlling the rotational speed of each roller in the extension direction of the scraper, so that the powder spreading surface can always remain flat.

[0057] The powder spreading device disclosed in the embodiment of the present invention may further include a powder spreading piece 150 and two scrapers 160. Please refer to Figure 1 again. The powder spreading piece 150 may be arranged at the bottom of the lower powder shaft 130. The powder spreading piece 150 may be provided with a powder spreading channel 151. The powder spreading channel 151 may face the lower powder shaft 130. At this time, the powder material output through the lower powder shaft 130 falls into the powder spreading channel 151 due to gravity. The powder spreading channel 151 may face the powder spreading surface, thereby allowing the powder material to fall onto the powder spreading surface through the powder spreading channel 151.

[0058] Furthermore, scrapers 160 can be provided on either side of the bottom of the powder spreading channel 151, extending along the length of the powder spreading channel 151. In this case, when spreading powder in a first spreading direction, one scraper 160 scrapes the powder to ensure smoothness of the spreading surface; when spreading powder in a direction opposite to the first spreading direction, the other scraper 160 scrapes the powder, thereby achieving bidirectional spreading. During installation, the two scrapers 160 can be symmetrically arranged around the bottom of the powder spreading channel 151 to better achieve bidirectional spreading.

[0059] The powder spreading device disclosed in the embodiment of the present invention may further include a material distribution mechanism 170, which is movably disposed within the lower powder bin and may extend along the length of the lower powder shaft 130. In this case, before the powder is conveyed through the lower powder shaft 130, the material distribution mechanism 170 is first moved to loosen the powder in the lower powder bin. This prevents agglomerated powder from falling into the lower powder shaft 130 and distributes the powder to various locations along the length of the lower powder shaft 130, thereby ensuring uniform powder delivery by the lower powder shaft 130.

[0060] Furthermore, the material distribution mechanism 170 can be movable in a variety of ways, such as vibration, up and down swinging, etc. In an optional solution, the material distribution mechanism 170 can include a material distribution body and a driving member, the driving member can be connected to the material distribution body, and the material distribution body can be provided with a toothed portion 171, which plays a role in loosening the powder in the lower powder bin to prevent agglomerated powder from falling into the lower powder shaft 130; and the driving member drives the toothed portion 171 to reciprocate in the length direction of the lower powder shaft 130 or the driving member drives the toothed portion 171 to rotate in the lower powder bin, thereby evacuating the powder to various positions along the length direction of the lower powder shaft 130 to ensure the uniformity of powder feeding of the lower powder shaft 130. Of course, the material distribution body can also add other ways of movement, that is, the material distribution body can be made to swing in a direction perpendicular to the axis of the lower powder shaft 130, thereby achieving a better effect of loosening the powder. Of course, the toothed portion 171 may be comb teeth. During operation, a plurality of continuously distributed teeth come into contact with the powder, thereby combing the powder. The toothed portion 171 may also be brush teeth, which is not limited in this embodiment of the present invention.

[0061] Furthermore, the material distribution body can have a variety of structures. Optionally, the material distribution body can be a single plate-like structure to facilitate processing and assembly. The material distribution body can also be a structural member with a "V"-shaped cross section, as shown in Figure 7. When assembled, the material distribution body of this structure can have the "V"-shaped opening facing the lower powder shaft 130, that is, the tooth-shaped portions 171 on both sides can face the lower powder shaft 130, thereby achieving a better loosening effect of the powder. The material distribution body can also be a spiral rod or a stirring rod with loosening blades, which rotates or reciprocates in the lower powder bin.

[0062] The powder spreading device disclosed in the embodiment of the present invention may further include a powder scraping mechanism 180, which may be disposed at the bottom of the lower powder shaft 130. The powder scraping mechanism 180 may be provided with a plurality of protrusions 181 spaced apart along its length that match the annular powder grooves 131, and each annular powder groove 131 may match a corresponding protrusion 181. In this case, when the powder rotates to the bottom of the lower powder shaft 130, a portion of the powder falls due to gravity, and the other portion of the powder stuck in the annular powder groove 131 can be scraped off by the powder scraping mechanism 180, thereby ensuring a quantitative powder supply while also cleaning the annular powder groove 131.

[0063] The specific shape of the powder scraping mechanism 180 can be various. In one optional embodiment, the scraper mechanism 180 can be a plate-shaped mechanism, as shown in Figures 2 and 3. In this case, the plate-shaped mechanism is inserted into the bottom of the powder discharge shaft 130. The protrusion 181 on the plate-shaped mechanism not only serves to quantitatively discharge powder but also cleans the annular powder trough 131. This structure of the scraper mechanism 180 is simple to manufacture, easy to install, and occupies a small amount of space.

[0064] In another optional embodiment, the scraper mechanism 180 may be a cylindrical mechanism, as shown in Figures 5 and 6. In this case, the cylindrical mechanism is disposed at the bottom of the powder lowering shaft 130. The protrusion 181 on the cylindrical mechanism not only serves to quantitatively discharge powder, but also serves to clean the annular powder trough 131. Furthermore, the cylindrical mechanism can rotate the bottom of the powder lowering shaft 130, and the protrusion 181 on the cylindrical mechanism can be an annular protrusion that matches the annular powder trough 131. During operation, the rotation direction of the cylindrical mechanism is opposite to that of the powder lowering shaft 130, thereby better serving the purpose of quantitatively discharging powder and better cleaning the annular powder trough 131. Alternatively, the cylindrical mechanism may be a brush roller.

[0065] In the embodiment of the present invention, the lower powder shaft 130 can be an integrally formed part or a machined part. In an alternative embodiment, the lower powder shaft 130 can include multiple rotating parts, which can be sequentially connected, and an annular powder groove 131 can be formed between adjacent rotating parts. This arrangement facilitates the molding of the lower powder shaft 130, particularly the formation of the annular powder groove 131.

[0066] In another alternative embodiment, the lower powder shaft 130 may be formed by casting, additive manufacturing, or machining. This method results in a lower powder shaft 130 with greater strength and precision. Of course, the lower powder shaft 130 may be formed by a variety of other methods, and this embodiment of the present invention does not limit this.

[0067] In the embodiment disclosed herein, a coating may be provided within the annular powder groove 131. The coating may have anti-sticking, anti-corrosion, and anti-rust properties to better ensure a quantitative powder delivery. The coating may be made of materials such as Teflon and silicon carbide, and the embodiment of the present invention does not limit this.

[0068] Based on the powder spreading device disclosed in the embodiment of the present invention, the embodiment of the present invention further discloses a 3D printing device, and the disclosed 3D printing device includes the powder spreading device described in any embodiment above.

[0069] Based on the powder spreading device disclosed in the embodiment of the present invention, the embodiment of the present invention further discloses a 3D printing device, which includes a frame 200, a powder spreading device 100, a printing device 300 and a moving device.

[0070] The frame 200 is the main component of the 3D printing device, thereby providing an installation location for other components of the 3D printing device. The printing device 300 and the powder spreading device 100 can both be movably arranged on the frame 200. The printing device 300 and the powder spreading device 100 are both connected to the motion device. The motion device simultaneously drives the powder spreading device 100 and the printing device 300 to move along different motion paths in an interlaced manner, so that the powder spreading device 100 and the printing device 300 can simultaneously spread powder and print. In this case, in the specific working process, by evenly laying a layer of powder material and spraying a layer of binder at the same time, layer by layer, a 3D entity is constructed. The 3D printing device provided by the present invention realizes the simultaneous operation of at least one powder spreading device 100 and at least one group of printing devices 300, and the powder spreading device 100 and the printing device 300 in the same group can work simultaneously, effectively eliminating the waiting time during the operation process, realizing uninterrupted powder spreading and printing, thereby greatly improving printing efficiency and reducing printing costs, providing a guarantee for promoting the industrial application of powder 3D printing in various fields.

[0071] On the other hand, powder spreading and printing can be carried out simultaneously, without wasting waiting time, which can significantly improve printing efficiency; on the other hand, multiple powder spreading devices 100 and multiple printing devices 300 can be used to simultaneously carry out printing work on different building platforms in the working area, and the models and layouts printed by each building platform can be personalized as needed.

[0072] Furthermore, the powder spreading device 100 includes a powder bin body 110, a powder blocking assembly 120 and a lower powder shaft 130. The powder blocking assembly 120 is arranged on one side of the powder bin body 110. The powder bin body 110 and the powder blocking assembly 120 constitute a lower powder bin. A lower powder port is formed at the bottom of the lower powder bin. The lower powder shaft 130 is rotatably arranged at the lower powder port and extends along the length direction of the lower powder port. The bottom of the powder blocking assembly 120 is in contact with the lower powder shaft 130. The lower powder shaft 130 is provided with a plurality of annular powder grooves 131 spaced apart along its length direction. When the lower powder shaft 130 rotates in a first direction, the powder in the lower powder bin is spread on the powder spreading surface through the annular powder grooves 131.

[0073] During the specific working process, please refer to Figure 2. The first direction can be counterclockwise. When powder needs to be discharged, the lower powder shaft 130 can rotate in the counterclockwise direction, thereby driving the powder in the lower powder bin to move. When the lower powder shaft 130 drives the powder to move to the position where the powder blocking component 120 is located, a portion of the powder is blocked by the powder blocking component 120, and the other portion of the powder in the annular powder groove 131 passes through the position where the powder blocking component 120 is located, and then gradually moves in the direction toward the powder laying surface through the rotation of the lower powder shaft 130, and is finally laid on the powder laying surface through the action of gravity. At this time, through the contact and cooperation between the powder blocking component 120 and the lower powder shaft 130, the powder in the lower powder bin can only be transported to the powder laying surface through the multiple annular powder grooves 131 through the rotation of the lower powder shaft 130, that is, the amount of powder delivered depends on the size of the annular powder grooves 131, so that the multiple annular powder grooves 131 play a role in quantitative powder discharge, so as to ensure the flatness of the powder laying surface and improve product quality.

[0074] Furthermore, embodiments of the present invention may further include a detection device, wherein the motion device and the detection device may be communicatively connected. The detection device may be used to detect the status of the printing device 300 and the powder spreading device 100. When the powder spreading device 100 completes a first powder spreading operation along a first direction, the motion device drives the printing device 300 to perform an inkjet operation on the first pass. When the powder spreading device 100 completes a second powder spreading operation along a second direction, the motion device drives the printing device 300 to perform an inkjet operation on the second pass. The reciprocating operation completes the printing and powder spreading operation. The first direction is opposite to the second direction, and the first and second passes gradually form a powder spreading surface. Of course, the number of the first and second passes can be one or more, ultimately forming the entire powder spreading printing surface.

[0075] Specifically, referring to Figure 8 , the direction indicated by the first arrow 190 is the direction of movement of the powder spreading device 100, and the direction indicated by the second arrow 310 is the direction of movement of the printing device 300. When the powder spreading device 100 completes a powder spreading stroke for the width of the printing device 300, the printing device 300 begins to spray a first layer of binder above the powder layer in a direction perpendicular to the powder spreading direction. The powder spreading device 100 continuously performs the powder spreading operation while the printing device 300 sprays the binder. When the powder spreading device 100 completes a second powder spreading stroke for the width of the printing device 300, the printing device 300 moves in the powder spreading direction by a distance of the width of the printing device 300 and then sprays a second layer of binder in the opposite direction of the movement of the printing device 300 when spraying the first layer of binder. This process repeats until the powder spreading device 100 and the printing device 300 complete the entire powder spreading and printing operation for the first layer. The uninterrupted coordination between the powder spreading device 100 and the printing device 300 makes operation more flexible and greatly improves printing efficiency.

[0076] Based on the 3D printing device described above, an embodiment of the present invention may further disclose a 3D printing method, which includes the following steps:

[0077] S100: When the powder spreading device 100 completes the powder spreading stroke of the width of the printing device 300, the printing device 300 starts to spray a first layer of binder above the powder layer in a direction perpendicular to the powder spreading direction;

[0078] S200: The powder spreading device 100 continuously performs a powder spreading operation while the printing device 300 is spraying the binder. When the powder spreading device 100 completes a second powder spreading stroke of the width of the printing device 300, the printing device 300 moves in the powder spreading direction by a stroke of the width of the printing device 300, and then sprays a second layer of binder in a direction opposite to the movement direction of the printing device 300 when spraying the first layer of binder.

[0079] S300, repeat this process until the powder spreading device 100 and the printing device 300 complete all the powder spreading and printing operations of the first layer.

[0080] This 3D printing method can effectively eliminate waiting time during the operation process and achieve uninterrupted powder laying and printing, thereby greatly improving printing efficiency and reducing printing costs, providing guarantees for promoting the industrial application of powder 3D printing in various fields.

[0081] In the 3D printing device disclosed in the embodiment of the present invention, the powder blocking assembly 120 may include a mounting portion 121 and a contact portion 122. The mounting portion 121 is detachably arranged on one side of the powder bin body 110, and the contact portion 122 is detachably arranged at the bottom of the mounting portion 121, and the contact portion 122 is in contact with the lower powder shaft 130.

[0082] Furthermore, the powder spreading device 100 includes a plurality of connecting baffles 140 of different sizes, which are used to connect the powder blocking assembly 120 and the powder bin body 110. The powder blocking assembly 120 contacts different positions on the lower powder shaft 130 through connecting baffles 140 of different sizes.

[0083] Furthermore, the powder blocking assembly 120 is rotatably disposed on one side of the powder bin body 110 , and the powder blocking assembly 120 contacts different positions on the lower powder shaft 130 by rotating.

[0084] Furthermore, the opening of the annular powder groove 131 gradually increases along the radial direction of the lower powder shaft 130 .

[0085] Furthermore, the lower powder shaft 130 includes a plurality of rollers, which are connected in sequence, and each roller is provided with an independent driving unit, which is used to drive each roller to rotate.

[0086] Furthermore, the lower powder shaft 130 also includes a central shaft, and a plurality of rollers are sequentially sleeved on the central shaft. A plurality of driving parts are arranged at intervals on the central shaft, and each roller is connected to the corresponding driving part.

[0087] Furthermore, the powder spreading device 100 also includes a powder spreading part 150 and two scrapers 160. The powder spreading part 150 is arranged at the bottom of the lower powder shaft 130. The powder spreading body is provided with a powder spreading channel 151. The powder spreading channel 151 faces the lower powder shaft 130, and scrapers 160 are respectively arranged on both sides of the bottom of the powder spreading channel 151. The scrapers 160 extend along the length direction of the powder spreading channel 151.

[0088] Furthermore, the powder spreading device 100 further includes a material distribution mechanism 170 , which is movably disposed in the lower powder bin and extends along the length direction of the lower powder shaft 130 .

[0089] Furthermore, the material distribution mechanism 170 includes a material distribution body and a driving member, which is drive-connected to the material distribution body. A toothed portion 171 is provided on the material distribution body, and the driving member drives the toothed portion 171 to reciprocate in the length direction of the lower powder shaft 130 .

[0090] Furthermore, the powder spreading device 100 also includes a powder scraping mechanism 180, which is arranged at the bottom of the lower powder shaft 130. The powder scraping mechanism 180 is provided with a plurality of protrusions 181 matching the annular powder grooves 131 spaced apart along its length direction, and each annular powder groove 131 matches the corresponding protrusion 181.

[0091] Based on the 3D printing device disclosed in the embodiment of the present invention, the embodiment of the present invention further discloses a 3D printing production line, including the 3D printing device described in any of the above embodiments.

[0092] The 3D printing production line disclosed in the embodiment of the present invention may further include a centralized sand mixing device 500 and a centralized liquid supply device 600. The number of 3D printing devices 400 may be multiple, and the multiple 3D printing devices 400 may be arranged at intervals. The multiple 3D printing devices 400 may all be connected to the centralized sand mixing device 500 and the centralized liquid supply device 600. The centralized sand mixing device 500 may be used to supply sand to each 3D printing device 400, and the centralized liquid supply device 600 may be used to supply liquid to each 3D printing device 400. In this case, multiple 3DP printing devices 400 are centrally planned and arranged to form a larger production system, thereby reducing the idle time of individual devices during production, improving the utilization efficiency of the equipment, and thus achieving efficient 3D printing.

[0093] The 3D printing production line disclosed in the embodiment of the present invention may further include a sand cleaning station 710, a drying station 720, a workpiece storage station 730 and a conveying mechanism 740. The sand cleaning station 710, the drying station 720 and the workpiece storage station 730 are arranged in sequence. The sand cleaning station 710 is used to perform sand cleaning on the printed workpiece. Specifically, the sand cleaning station 710 may include a truss, a sand cleaning device and a sand blowing device. The sand cleaning device and the sand blowing device may be located on the truss in sequence, so that the sand cleaning of the printed workpiece may be achieved by grabbing the truss; or the sand cleaning work may be achieved by roller conveying, which is not limited in the embodiment of the present invention.

[0094] The drying station 720 is used to dry the printed workpiece. Of course, it can also include a flow coating station in the future to realize flow coating treatment of some workpieces; the workpiece storage station 730 plays the role of temporarily storing the printed workpiece. Optionally, the printed workpiece can be transported to the workpiece storage station 730 by a transfer cart, or the printed workpiece can be temporarily stored or grabbed by scanning the code for automatic storage and outbound transportation, so as to better organize the printed workpieces.

[0095] The conveying mechanism 740 is used to transport the printed workpieces from each 3D printing device 400 to each workstation to ensure printing production efficiency. Optionally, the conveying mechanism 740 can be a separate transfer vehicle, or can include a conveying roller and a transfer vehicle movable on the conveying roller, or can be other mechanisms capable of conveying, and this embodiment of the present invention is not limited to this.

[0096] In an embodiment of the present invention, multiple 3D printing devices 400 can be arranged in one or more rows. Please refer to Figures 9 and 10. Specifically, multiple 3D printing devices 400 can be arranged in one or more rows according to the spatial layout, thereby achieving efficient 3D printing by rationally utilizing the spatial layout.

[0097] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A powder spreading device, characterized in that: The invention comprises a powder bin body (110), a powder blocking assembly (120) and a lower powder shaft (130), wherein the powder blocking assembly (120) is arranged on one side of the powder bin body (110), the powder bin body (110) and the powder blocking assembly (120) constitute a lower powder bin, a lower powder opening is formed at the bottom of the lower powder bin, the lower powder shaft (130) is rotatably arranged at the lower powder opening and is extended along the length direction of the lower powder opening, the bottom of the powder blocking assembly (120) is in contact with the lower powder shaft (130), and the lower powder shaft (130) is provided with a plurality of annular powder grooves (131) spaced apart along the length direction thereof, and when the lower powder shaft (130) rotates along a first direction, the powder in the lower powder bin is spread on a powder spreading surface through the annular powder grooves (131).

2. The powder spreading device according to claim 1, characterized in that: The powder blocking assembly (120) comprises a mounting portion (121) and a contact portion (122), wherein the mounting portion (121) is detachably arranged on one side of the powder bin body (110), and the contact portion (122) is detachably arranged on the bottom of the mounting portion (121), and the contact portion (122) is in contact with the lower powder shaft (130).

3. The powder spreading device according to claim 1, characterized in that: It comprises a plurality of connecting baffles (140) of different sizes, wherein the connecting baffles (140) are used to connect the powder blocking assembly (120) and the powder bin body (110), and the powder blocking assembly (120) contacts different positions on the lower powder shaft (130) through the connecting baffles (140) of different sizes.

4. The powder spreading device according to claim 1, characterized in that: The powder blocking component (120) is rotatably arranged on one side of the powder bin main body (110), and the powder blocking component (120) contacts different positions on the lower powder shaft (130) through rotation.

5. The powder spreading device according to claim 1, characterized in that: The opening of the annular powder groove (131) gradually increases in the radial direction of the lower powder axis (130).

6. The powder spreading device according to claim 1, characterized in that: The lower powder shaft (130) comprises a plurality of rollers, the plurality of rollers are connected in sequence, and each roller is provided with an independent driving unit, the driving unit being used to drive each roller to rotate.

7. The powder spreading device according to claim 6, characterized in that: The lower powder shaft (130) further comprises a central shaft, a plurality of rollers are sequentially sleeved on the central shaft, a plurality of driving parts are arranged at intervals on the central shaft, and each roller is drivingly connected to a corresponding driving part.

8. The powder spreading device according to claim 1, characterized in that: It also comprises a powder spreading member (150) and two scrapers (160), wherein the powder spreading member (150) is arranged at the bottom of the lower powder shaft (130), the powder spreading member (150) is provided with a powder spreading channel (151), the powder spreading channel (151) faces the lower powder shaft (130), and the scrapers (160) are respectively arranged on both sides of the bottom of the powder spreading channel (151), and the scrapers (160) extend along the length direction of the powder spreading channel (151).

9. The powder spreading device according to claim 1, characterized in that: It also comprises a material distribution mechanism (170), wherein the material distribution mechanism (170) is movably arranged in the lower powder bin, and the material distribution mechanism (170) extends along the length direction of the lower powder shaft (130).

10. The powder spreading device according to claim 9, characterized in that: The material distribution mechanism (170) comprises a material distribution body and a driving member, the driving member being drivingly connected to the material distribution body, the material distribution body being provided with a toothed portion (171), the driving member driving the toothed portion (171) to reciprocate in the length direction of the lower powder shaft (130) or to rotate in the lower powder bin.

11. The powder spreading device according to claim 1, characterized in that: The invention also comprises a powder scraping mechanism (180), wherein the powder scraping mechanism (180) is arranged at the bottom of the lower powder shaft (130), and the powder scraping mechanism (180) is provided with a plurality of protrusions (181) matching the annular powder grooves (131) at intervals along its length direction, and each of the annular powder grooves (131) matches the corresponding protrusion (181).

12. The powder spreading device according to claim 1, characterized in that: The lower powder shaft (130) comprises a plurality of rotating parts, the plurality of rotating parts are connected in sequence, and the annular powder groove (131) is formed between two adjacent rotating parts.

13. The powder spreading device according to claim 1, characterized in that: The lower powder shaft (130) is formed by casting, additive manufacturing, and machining.

14. The powder spreading device according to claim 1, characterized in that: A coating is provided in the annular powder groove (131).

15. A 3D printing device, characterized in that: A powder spreading device comprising the powder spreading device described in any one of claims 1 to 14.

16. A 3D printing device, characterized in that: The invention comprises a frame (200), a powder spreading device (100), a printing device (300) and a moving device, wherein the printing device (300) and the powder spreading device (100) are both movably arranged on the frame (200), the printing device (300) and the powder spreading device (100) are both drivingly connected to the moving device, and the moving device simultaneously drives the powder spreading device (100) and the printing device (300) to move alternately along different movement paths, so that the powder spreading device (100) and the printing device (300) can simultaneously spread powder and print, and the powder spreading device (100) comprises a powder bin body (110), a powder blocking assembly (120) and a lower powder shaft (130), the powder blocking component (120) is arranged on one side of the powder bin body (110), the powder bin body (110) and the powder blocking component (120) constitute a lower powder bin, a lower powder opening is formed at the bottom of the lower powder bin, the lower powder shaft (130) is rotatably arranged at the lower powder opening, and is extended along the length direction of the lower powder opening, the bottom of the powder blocking component (120) is in contact with the lower powder shaft (130), and the lower powder shaft (130) is provided with a plurality of annular powder grooves (131) spaced apart along its length direction, and when the lower powder shaft (130) rotates along a first direction, the powder in the lower powder bin is spread on the powder spreading surface through the annular powder grooves (131).

17. The 3D printing device according to claim 16, characterized in that: The invention also comprises a detection device, wherein the motion device is communicatively connected to the detection device, and the detection device is used to detect the states of the printing device (300) and the powder spreading device (100); when the powder spreading device (100) completes a first powder spreading operation along a first direction, the motion device drives the printing device (300) to perform an inkjet operation on the first layer; when the powder spreading device (100) completes a second powder spreading operation along a second direction, the motion device drives the printing device (300) to perform an inkjet operation on the second layer; the reciprocating operation completes the printing and powder spreading operation; the first direction is opposite to the second direction.

18. The 3D printing device according to claim 16, characterized in that: The powder blocking assembly (120) comprises a mounting portion (121) and a contact portion (122), wherein the mounting portion (121) is detachably arranged on one side of the powder bin body (110), and the contact portion (122) is detachably arranged on the bottom of the mounting portion (121), and the contact portion (122) is in contact with the lower powder shaft (130).

19. The 3D printing device according to claim 16, characterized in that: The powder spreading device (100) comprises a plurality of connecting baffles (140) of different sizes, wherein the connecting baffles (140) are used to connect the powder blocking assembly (120) and the powder bin body (110), and the powder blocking assembly (120) contacts different positions on the lower powder shaft (130) via the connecting baffles (140) of different sizes.

20. The 3D printing device according to claim 16, characterized in that: The powder blocking component (120) is rotatably arranged on one side of the powder bin main body (110), and the powder blocking component (120) contacts different positions on the lower powder shaft (130) through rotation.

21. The 3D printing device according to claim 16, characterized in that: The opening of the annular powder groove (131) gradually increases in the radial direction of the lower powder axis (130).

22. The 3D printing device according to claim 16, characterized in that: The lower powder shaft (130) comprises a plurality of rollers, the plurality of rollers are connected in sequence, and each roller is provided with an independent driving unit, the driving unit being used to drive each roller to rotate.

23. The 3D printing device according to claim 22, characterized in that: The lower powder shaft (130) further comprises a central shaft, a plurality of rollers are sequentially sleeved on the central shaft, a plurality of driving parts are arranged at intervals on the central shaft, and each roller is drivingly connected to a corresponding driving part.

24. The 3D printing device according to claim 16, characterized in that: The powder spreading device (100) further comprises a powder spreading member (150) and two scrapers (160), wherein the powder spreading member (150) is arranged at the bottom of the lower powder shaft (130), the powder spreading body is provided with a powder spreading channel (151), the powder spreading channel (151) faces the lower powder shaft (130), and the scrapers (160) are respectively arranged on both sides of the bottom of the powder spreading channel (151), and the scrapers (160) extend along the length direction of the powder spreading channel (151).

25. The 3D printing device according to claim 16, characterized in that: The powder spreading device (100) further comprises a material distribution mechanism (170), wherein the material distribution mechanism (170) is movably arranged in the lower powder bin, and the material distribution mechanism (170) extends along the length direction of the lower powder shaft (130).

26. The 3D printing device according to claim 25, characterized in that: The material distribution mechanism (170) comprises a material distribution body and a driving member, the driving member being drivingly connected to the material distribution body, the material distribution body being provided with a toothed portion (171), the driving member driving the toothed portion (171) to reciprocate in the length direction of the lower powder shaft (130) or the driving member driving the toothed portion (171) to rotate in the lower powder bin.

27. The 3D printing device according to claim 16, characterized in that: The powder spreading device (100) further comprises a powder scraping mechanism (180), the powder scraping mechanism (180) being arranged at the bottom of the lower powder shaft (130), the powder scraping mechanism (180) being provided with a plurality of protrusions (181) matching the annular powder grooves (131) at intervals along its length direction, and each of the annular powder grooves (131) matching the corresponding protrusion (181).

28. A 3D printing production line, characterized in that: A 3D printing device (400) comprising any one of claims 15 to 27.

29. The 3D printing production line according to claim 28, characterized in that: It also includes a centralized sand mixing device (500) and a centralized liquid supply device (600), the number of the 3D printing devices (400) is multiple, the multiple 3D printing devices (400) are arranged at intervals, the multiple 3D printing devices (400) are all connected to the centralized sand mixing device (500) and the centralized liquid supply device (600), the centralized sand mixing device (500) is used to supply sand to each of the 3D printing devices (400), and the centralized liquid supply device (600) is used to supply liquid to each of the 3D printing devices (400).

30. The 3D printing production line according to claim 28, characterized in that: It also includes a sand cleaning station (710), a drying station (720), a workpiece storage station (730) and a conveying mechanism (740), wherein the sand cleaning station (710), the drying station (720) and the workpiece storage station (730) are arranged in sequence, and the conveying mechanism (740) is used to convey the printed workpieces on each 3D printing device (400) to each station.

31. The 3D printing production line according to any one of claims 28 to 30, characterized in that: The plurality of 3D printing devices (400) are arranged in one row or multiple rows.

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