3D printing platform with reinforced screws

Abstract

The invention relates to a divisional application, and provides a 3D printing platform with a reinforced screw rod, which comprises a printing platform mounted on a connecting arm of a transmission mechanism, a guide rod hole is formed in the printing platform, the guide rod hole extends in the vertical direction and penetrates through the upper side and the lower side of the printing platform, an internal thread part is detachably installed on the printing platform, and a reinforcing screw is screwed into an internal thread hole of the internal thread part; the printing platform is further provided with a driving device used for driving the reinforcing screw to rotate. The model is bonded on the printing platform, and a reinforced hole is formed in the model; under the driving of the driving device, the reinforcing screw rod can move in a reciprocating mode in the vertical direction, and the reinforcing screw rod is screwed into the reinforcement hole or withdrawn from the model. According to the application, the problem that the model is fractured or cracks and even separation are generated between the model and a printing platform due to the influence of gravity and the bonding force effect of the release film in the printing process can be effectively reduced or even avoided.

Description

[0001] This application is a divisional application. The application date of the original application is September 27, 2024. The application number is 202411358714X. The name of the invention is: An enhanced 3D printer and an enhanced 3D printing method. Technical Field

[0002] The invention relates to 3D printing technology, and in particular to a 3D printing platform with a reinforced screw. Background Art

[0003] DLP, LCD / LED and other 3D printing methods project a surface imaging beam formed according to the sliced ​​cross-sectional pattern of the three-dimensional model onto the photosensitive resin printing material to achieve single-layer solidification, and thus the three-dimensional model is formed by curing and stacking the layers. During the printing process, the unfinished model needs to be frequently lifted upward to separate the model from the release film and allow the photosensitive resin to enter between the model and the release film to continue printing the next solidified layer. During the frequent lifting process, the model interior and between the model and the printing platform are subjected to frequent tensile stress, causing the model to crack or break and the model to separate from the printing platform. In order to prevent the unfinished printed model from cracking, breaking or separating from the printing platform, the contact surface between the printing platform and the model is often set to a rough surface to improve the bonding force between the model and the printing platform. Although this method can prevent the model from separating from the printing platform to a certain extent, it still cannot prevent the model from breaking from a thinner cross section. Although adding auxiliary support ribs can improve the overall strength of the model, it still cannot prevent the model from breaking, especially the model separating from the printing platform, which leads to printing failure. Therefore, how to avoid the breakage of the model itself and the cracks or even separation between the model and the printing platform during the printing process is still a problem to be solved in this field. Summary of the invention

[0004] In order to solve the problem of the model breaking or cracking or even separation from the printing platform in the prior art, the present application proposes a 3D printing platform with a reinforced screw, which includes a printing platform detachably mounted on a connecting arm of a transmission mechanism, the lower surface of the printing platform is formed as a working surface, and the connecting arm can drive the printing platform to reciprocate in the vertical direction;

[0005] A guide rod hole is provided on the printing platform, the guide rod hole extends in the vertical direction and passes through the upper and lower sides of the printing platform, and an internal threaded part is detachably installed on the printing platform, the internal threaded part has an internal threaded hole coaxially arranged with the guide rod hole, the reinforcing screw is screwed into the internal threaded hole of the internal threaded part and can pass through the guide rod hole downward; a driving device for driving the reinforcing screw to rotate is also installed on the printing platform; the model is bonded to the printing platform, and a reinforcement hole is formed in the model; under the drive of the driving device, the reinforcing screw can reciprocate in the vertical direction, and when the reinforcing screw moves downward, it can extend downward from the guide rod hole and be screwed into the reinforcement hole; when the reinforcing screw moves upward, it can withdraw from the model and retract the lower end of the reinforcing screw into the guide rod hole. Specifically, the reinforcing screw is made of metal or alloy materials such as steel, copper, and aluminum.

[0006] In this application, a reinforcing screw is arranged on the printing platform, and the reinforcing screw can be screwed downward into the model, and the high strength of the reinforcing screw is used to improve the connection strength between the model and the printing platform, and after printing is completed, the reinforcing screw is withdrawn from the model so as to facilitate the removal of the model from the printing platform. In the process of screwing the reinforcing screw into the reinforcement hole, some resin debris will inevitably be produced, and these resin debris will fall into the resin in the material tank. In order to facilitate the cleaning of these numerical debris, the material tank is fixedly installed on the workbench, and the material tank is rectangular. The inner cavity of the material tank is divided into a working area and a non-working area surrounding the working area. A scraper is installed in the material tank, and the scraper can move from one side of the material tank to the other side opposite to push the solid particles deposited at the bottom of the material tank from the working area to the non-working area; in the vertical direction, the projection of the printing platform is located in the working area. The scraper is used to push the solid particles such as resin debris that fall and deposit at the bottom of the material tank from the working area to the non-working area, so as to avoid the model from being pressed by larger solid particles during the descent of the model, thereby causing damage to the release film. In order to prevent the resin debris generated by the scraper from being retained in the working area during its operation, the reinforcing screw stops rotating and remains stationary after each curing layer is printed and before the next curing layer is printed. The reinforcing screw only rotates during the printing process of each curing layer to screw the model downward.

[0007] Since the reinforcing screw can be screwed into the model, the model has a higher tensile strength during the printing process, which can effectively reduce or even avoid cracks or even breakage of the model due to the influence of gravity and the bonding force of the release film during the printing process.

[0008] The present application separately sets an internal threaded part on the printing platform, and different internal threaded parts can be replaced according to different outer diameters and thread forms of the reinforcing screw to facilitate printing of models of different types.

[0009] Furthermore, the reinforcing screw is a hollow screw that opens downwards. The inner cavity of the reinforcing screw can be used to contain part of the resin powder generated during the screwing process of the reinforcing screw, thereby reducing the amount of resin powder falling into the material tank.

[0010] Specifically, the transmission mechanism has a ball screw extending in a vertical direction, a connecting arm is engaged with the ball screw, a free end of the connecting arm is formed as a working end, and the printing platform is detachably mounted on the working end;

[0011] One end of the connecting arm away from the ball screw has two clamping arms arranged at intervals in the horizontal direction. The two clamping arms extend in a direction away from the ball screw and are parallel to each other. A platform accommodating cavity is formed between the two clamping arms. The platform accommodating cavity has an opening facing away from the ball screw. Corresponding to each clamping arm, a clamping groove is respectively provided on two opposite sides of the printing platform. The printing platform is inserted into the platform accommodating cavity, and each clamping arm is inserted into the corresponding clamping groove. Each clamping arm is fixed to the printing platform by bolts, and the driving device is installed on the upper surface of the printing platform.

[0012] In this design, the printing platform is mounted on the connecting arm using a clamping arm, thereby leaving the top of the printing platform empty, so that the reinforcing screw can be smoothly screwed down from the top of the printing platform into the model, and the driving device can be installed on the upper surface of the printing platform so that the driving device can be conveniently connected to the reinforcing screw and drive the reinforcing screw so that the reinforcing screw can be screwed into the reinforcement hole of the model.

[0013] Specifically, the driving device includes a driving member and a solid shaft servo motor. The driving member is rotatably mounted on the upper side of the printing platform via a bearing. The driving member has an axial hole through which the reinforcing screw freely passes. One side of the reinforcing screw has a cutting plane, and a protrusion is provided in the axial hole. The solid shaft servo motor is fixedly mounted on the upper side of the printing platform and on one side of the driving member. The output shaft of the solid shaft servo motor is connected to the driving member. When the solid shaft servo motor drives the driving member to rotate, the protrusion can press against the cutting plane and drive the reinforcing screw to rotate. Under the restriction of the internal threaded member, the reinforcing screw can reciprocate in the vertical direction while rotating. Or,

[0014] The driving device includes a driving member and a hollow shaft torque motor. The hollow shaft torque motor includes a stator and a mover rotatably arranged in the stator. The outer hollow shaft is fixed on the mover, and the inner hollow shaft is fixed on the outer hollow shaft. The outer hollow shaft, the inner hollow shaft and the guide rod hole are coaxially arranged. The driving member is detachably fixed on the inner hollow shaft. The driving member has a through-axis hole. The reinforcing screw rod freely passes through the through-axis hole. One side of the reinforcing screw rod has a cutting plane, and a radially outward protrusion is provided in the through-axis hole. When the mover drives the driving member to rotate, the protrusion can be pressed against the cutting plane and drive the reinforcing screw rod to rotate. Under the restriction of the internal threaded member, the reinforcing screw rod reciprocates in the vertical direction while rotating. The hollow shaft torque motor is a servo motor.

[0015] The above two structural forms of the driving device can both meet the driving needs of the reinforcing screw and can be selected according to the specific structural formation and usage habits of the equipment.

[0016] The enhanced 3D printing method performed by the enhanced 3D printer described in any one of the above comprises the following steps:

[0017] (1) After the 3D modeling of the model to be printed is completed, a cylindrical reinforced area with a set diameter is calculated, and the reinforced area can at least extend to an outer end surface of the model to be printed. The extension direction of the reinforced area is perpendicular to the outer end surface, and the outer end surface is used as the starting surface when the model is printed;

[0018] (2) Printing the model to be printed with the outer end surface as the starting surface, forming a reinforcement hole in the reinforcement area during the printing process of the solidified layer of the model, the reinforcement hole is coaxially arranged with the reinforcing screw, and the inner diameter of the reinforcement hole is less than the outer diameter of the thread of the reinforcing screw; rotating the reinforcing screw to screw the reinforcing screw into the reinforcement hole; and keeping the reinforcing screw stationary during the printing interval between two adjacent solidified layers;

[0019] After each solidified layer is printed, the printing platform is lifted upwards, and after the solidified layer is separated from the release film of the material tank, the scraper is started to move from one side of the material tank to the other side to push the solid particles deposited at the bottom of the material tank from the working area to the non-working area;

[0020] (3) When printing is completed, the reinforcing screw is withdrawn from the printed model.

[0021] In the 3D printing method of the present application, during the printing process, the reinforcing screw is screwed into the model, and the high strength of the reinforcing screw is used to improve the connection strength between the model and the printing platform. After printing is completed, the reinforcing screw is withdrawn from the model to facilitate the removal of the model from the printing platform. In the process of the reinforcing screw being screwed into the reinforcement hole, some resin debris will inevitably be produced, and these resin debris will fall into the resin in the material tank. The solid particles such as the resin debris that fall and deposit at the bottom of the material tank are pushed from the working area to the non-working area by a scraper to avoid the model being pressed against larger solid particles during the descent process, thereby causing damage to the release film. In order to avoid the resin debris generated during the operation of the scraper being retained in the working area, the reinforcing screw stops rotating and remains stationary after each solidified layer is printed and before the next solidified layer is printed. The reinforcing screw is only rotated during the printing process of each solidified layer to screw down the model.

[0022] Since the reinforced screw can be screwed into the model, the model also has higher tensile strength during the printing process, which can effectively reduce or even avoid cracks or even breakage of the model due to the influence of gravity and the adhesive force of the release film during the printing process.

[0023] The present application utilizes the good toughness of the resin so that when the reinforcing screw is screwed in the reinforcement hole, the threads of the reinforcing screw are cut to form an internal thread that meshes with the threads of the reinforcing screw.

[0024] Furthermore, to avoid cracks or breaks in the model when the reinforcing screw is screwed in the reinforcing hole, the diameter of the reinforcing area is set to be ≥10mm larger than the outer diameter of the reinforcing screw. This design makes the wall thickness of the reinforcing hole at least 5mm, so that the area where the reinforcing hole is set still has a high strength and can withstand the downward thrust generated by the reinforcing screw during the screwing process.

[0025] Furthermore, in order to smoothly screw the reinforcing screw into the model, D1-D2=(0.5-1)W, where D1 is the outer diameter of the thread of the reinforcing screw, D2 is the inner diameter of the reinforcement hole, and W is the height of the thread of the reinforcing screw. Since the model is a resin product, it has a certain deformation ability. Even if the difference between D1 and D2 is less than W, a complete thread can still be formed by utilizing the deformation ability of the resin. The difference between D1 and D2 is determined according to the deformation ability of the resin. In a specific embodiment, corresponding experiments need to be conducted to determine the difference between D1 and D2.

[0026] Furthermore, in order to ensure the integrity of the model appearance, the lower end of the reinforced hole is a closed end, and the wall thickness of the closed end is 0.5-2 mm.

[0027] Furthermore, in order to prevent the reinforcing screw from touching the release film of the material tank during printing, the distance between the lower end surface of the reinforcing screw and the to-be-printed solidified layer is 2-5 mm. The reinforcing screw is always kept at a certain distance from the to-be-printed solidified layer, which ensures the strength of the model and the smooth progress of printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic structural diagram of an embodiment of an enhanced 3D printer in the present invention.

[0029] Figure 2 yes Figure 1 Connection structure diagram between the middle drive device and the printing platform.

[0030] Figure 3 yes Figure 2 Center AA view.

[0031] Figure 4 It is a schematic diagram of the structure of the connecting arm.

[0032] Figure 5 It is a structural diagram of the connection between the driving member and the reinforcing screw.

[0033] Figure 6 This is a top view of the trough.

[0034] Figure 7 yes Figure 6 View from the center BB direction.

[0035] Figure 8 It is a structural schematic diagram of another embodiment of the enhanced 3D printer in the present invention. DETAILED DESCRIPTION

[0036] Example 1

[0037] See also Figure 1-Figure 7 An enhanced 3D printer includes a workbench 11, on which a transmission mechanism is installed. The transmission mechanism adopts existing mature technology. The transmission mechanism includes a vertical pole 12 fixed on the workbench 11 and a ball screw 13 rotatably installed on one side of the vertical pole. The ball screw 13 extends in the vertical direction, and one end of a connecting arm 14 is engaged with the ball screw through a screw hole. The connecting arm 14 extends in the horizontal direction, and a printing platform 20 is detachably installed at one end of the connecting arm 14 away from the ball screw. A servo motor is installed at the lower end of the ball screw, and the servo motor is fixedly installed on the vertical pole. The servo motor can drive the ball screw to rotate, so that the connecting arm can drive the printing platform to reciprocate in the vertical direction.

[0038] The trough 17 is fixedly installed on the workbench. The trough 17 is rectangular and specifically includes a trough wall 171 extending in the vertical direction. A release film 174 is provided at the bottom of the trough wall. A trough flange 175 is provided on the outer side of the bottom of the trough wall. Bolts pass through the trough flange 175 and are screwed onto the workbench to detachably fix the trough on the workbench. The inner cavity of the trough is divided into a working area 173 and a non-working area 172, wherein the non-working area surrounds the working area. Figure 6 In the figure, a double-dotted line 176 is used as the boundary between the working area 173 and the non-working area 172. In the vertical direction, the projection of the printing platform is located in the working area.

[0039] A scraper system 18 is also installed on the workbench, and the scraper system 18 includes a scraper 181 arranged in the material trough, and the scraper 181 is parallel to a side wall of the trough wall 171. A screw 183 and a slide rail 185 are respectively arranged at both ends of the scraper in the length direction. The screw and the slide rail are both located outside the material trough, wherein the screw is rotatably installed on the workbench through a bearing seat, and the slide rail is fixedly installed on the workbench, and the screw and the slide rail are perpendicular to the length direction of the scraper. A first U-shaped arm 182 is connected to one end of the scraper in the length direction, and the first U-shaped arm 182 is engaged with the screw through a screw nut, and a second U-shaped arm 186 is connected to the other end of the scraper in the length direction, and the second U-shaped arm 186 is slidably supported on the slide rail through a slide groove. One end of the screw is fixedly connected to the output shaft of a drive motor 184, and the drive motor is installed on the workbench. The blade of the scraper is against the release film. Driven by the drive motor, the screw can drive the scraper to move from one side of the material tank to the other side, pushing the solid particles deposited at the bottom of the material tank from the working area to the non-working area. An ultraviolet light system is installed in the workbench, and the ultraviolet light system includes a liquid crystal screen fixed on the top plate of the workbench. The material tank is arranged above the liquid crystal screen. The ultraviolet light system is not shown in the attached drawings. The ultraviolet light system adopts existing mature technology and will not be described in detail.

[0040] In this embodiment, the printing platform 20 includes a main body 21, a connecting portion 24 and a model plate 23, wherein the connecting portion 24 is integrally formed on the upper side of the main body 21, and a platform flange 22 is provided on the lower side of the main body 21. The model plate 23 is detachably mounted on the platform flange 22 by bolts, and the lower surface of the model plate 23 is formed as a working surface 231.

[0041] In this embodiment, two clamping arms 141 are arranged at intervals in the horizontal direction at one end of the connecting arm 14 away from the ball screw. The two clamping arms 141 extend in a direction away from the ball screw and are parallel to each other. A platform accommodating cavity 142 is formed between the two clamping arms. The platform accommodating cavity has an opening facing away from the ball screw. Corresponding to each clamping arm 141, a clamping groove 25 is respectively arranged on the opposite sides of the printing platform. The clamping groove is specifically arranged on the opposite sides of the connecting portion 24. The printing platform 20 is inserted into the platform accommodating cavity 142, and each clamping arm 141 is inserted into the corresponding clamping groove 25. The first bolt 16 passes through the clamping arm and is screwed into the first screw hole 251 located in the clamping groove, so that the clamping arm is detachably fixed to the printing platform. To avoid shaking, each clamping arm is fixed to the printing platform by two first bolts.

[0042] A guide rod hole is provided on the printing platform, and the guide rod hole includes an upper guide rod hole 27 provided in the body and a lower guide rod hole 28 provided in the model plate, and both the upper guide rod hole and the lower guide rod hole are through holes and are coaxially arranged. The upper guide rod hole 27 penetrates the upper surface of the connecting portion 24 upward, and the lower guide rod hole 28 penetrates the lower surface of the model plate 23 downward. That is, the guide rod hole extends in the vertical direction and penetrates the upper and lower sides of the printing platform.

[0043] The upper end of the upper guide rod hole 27 is radially expanded to form an embedded hole, and the internal threaded member 26 is tightly inserted in the embedded hole. The internal threaded member 26 has an internal threaded hole, and the internal threaded hole is coaxially arranged with the guide rod hole. Specifically in this embodiment, the internal threaded member is a hexagonal nut, and the inner peripheral wall of the embedded hole is a hexagon with the same shape as the outer peripheral surface of the hexagonal nut. The inner diameter of the internal threaded hole is smaller than the inner diameter of the guide rod hole. According to the different thicknesses and different forms of thread teeth of the reinforcing screw, the corresponding internal threaded member can be replaced. In order to facilitate the installation of the hollow shaft torque motor 70 described below, the upper surface of the internal threaded member 26 is not higher than the upper surface of the connecting portion, that is, the upper surface of the internal threaded member 26 is not higher than the upper surface of the printing platform.

[0044] The driving device is installed on the upper surface of the printing platform. Specifically, in this embodiment, the driving device includes a first driving member 83 and a hollow shaft torque motor 70, which is a servo motor. The hollow shaft torque motor 70 includes a stator 71 and a mover 75 rotatably arranged in the stator 71, and an outer hollow shaft 86 is fixed on the mover 75. An upper end cover 72 and a lower end cover 73 are respectively installed at the upper and lower ends of the stator 71, wherein the upper end cover 72 is bolted to the upper flange 711 at the upper end of the stator 71, and the lower end cover 73 is bolted to the lower flange 712 at the lower end of the stator 71, and the upper flange 711 and the lower flange 712 are both integrally formed on the stator 71, and a winding 74 is arranged on the inner side of the stator.

[0045] In this embodiment, an upper connecting flange 76 is provided on the outer peripheral surface of the outer hollow shaft 86, and the upper end cover has an upper abutting flange 721 protruding inwardly, and the lower surface of the upper abutting flange 721 is a step surface facing downward. The upper abutting flange 721 is pressed against the upper side of the outer ring of the upper angular contact bearing 78 through its lower surface, and the upper connecting flange 76 is pressed against the lower side of the inner ring of the upper angular contact bearing, so that the upper end cover is rotatably connected to the outer hollow shaft 86 through the upper angular contact bearing.

[0046] A lower step portion 77 is provided at the lower end of the outer hollow shaft 86, and the lower step portion has a step surface facing downward, and the lower step portion 77 is formed by the outer peripheral surface of the outer hollow shaft 86 being recessed radially inward; the lower end cover has a lower abutting flange 731 protruding inward, and the upper surface of the lower abutting flange 731 is a step surface facing upward, and the lower abutting flange 731 abuts against the lower side of the outer ring of the lower angular contact bearing 79 through its upper surface, and the lower step portion 77 abuts against the lower side of the inner ring of the lower angular contact bearing, so that the lower end cover is rotatably connected to the outer hollow shaft 86 through the lower angular contact bearing. The structure of the hollow shaft torque motor can be completed by using existing mature technology, and no further description is given.

[0047] The lower end cover 73 is detachably mounted on the upper surface of the connecting portion via bolts, thereby mounting the hollow shaft torque motor 70 on the upper surface of the connecting portion.

[0048] The inner hollow shaft 81 is lined in the inner cavity of the outer hollow shaft 86, and a flange 811 is provided on the top of the inner hollow shaft 81. The flange 811 is formed by the outer circumferential surface of the inner hollow shaft 81 protruding radially outward, and the top of the outer hollow shaft is fixed to the flange 811 by bolts. In order to ensure the connection stability between the inner hollow shaft and the outer hollow shaft, a key 85 is provided between the inner hollow shaft and the outer hollow shaft. The outer hollow shaft, the inner hollow shaft and the guide rod hole are coaxially arranged.

[0049] The top of the inner cavity of the inner hollow shaft has a regular hexagonal counterbore 812, and an external thread 82 is provided on the outer wall of the top of the inner hollow shaft. The first drive member 83 is accommodated in the counterbore, and the pressure cap 84 is screwed on the external thread to keep the first drive member 83 in the counterbore, so that the first drive member can be detachably mounted on the inner hollow shaft, and the first drive member has an outer peripheral surface with the same shape as the counterbore, so that the inner hollow shaft can drive the first drive member to rotate synchronously. The first drive member has a first through-shaft hole 831. When observed along the axial direction of the first through-shaft hole, the cross section of the first through-shaft hole 831 includes a major arc 832 and a straight line segment 833 closing the major arc 832, so that the first through-shaft hole is formed by a circular hole, and has a radially inward protrusion in the circular hole, wherein the area where the straight line segment is located is formed as the protrusion.

[0050] The reinforcing screw 40 freely passes through the first through-shaft hole and is screwed into the internal threaded hole of the internal threaded member, and can pass downward through the guide rod hole. A tangent plane 41 that can adapt to the above-mentioned protrusion is provided on one side of the reinforcing screw 40. When the mover drives the first driving member to rotate through the inner hollow shaft, the protrusion can press against the tangent plane and drive the reinforcing screw to rotate. Under the restriction of the internal threaded member, the reinforcing screw moves back and forth in the vertical direction while rotating. The model 30 is bonded to the printing platform, and a reinforced hole 31 is formed in the model. When the reinforcing screw moves downward, the reinforcing screw can extend downward from the guide rod hole and be screwed into the reinforced hole 31; when the reinforcing screw moves upward, it can withdraw from the model 30 and retract the lower end of the reinforcing screw into the guide rod hole. In this embodiment, the reinforcing screw 40 is a stainless steel hollow screw. It can be understood that in other embodiments, the reinforcing screw can also be made of metal or alloy materials such as copper and aluminum.

[0051] For details about the reinforced holes 31, please refer to the relevant content in Example 3 below.

[0052] Example 2

[0053] See also Figure 8 This embodiment is basically the same as the first embodiment, and the only difference is the driving device. Figure 8 and Figure 1-Figure 5 The same reference numerals represent the same technical features. In the present embodiment, the driving device comprises a second driving member 66 and a solid shaft servo motor 61. A bearing seat 64 is fixedly installed on the upper surface of the connecting portion 24 of the printing platform by bolts, and the second driving member 66 is rotatably installed on the bearing seat 64 via a rolling bearing 65. The solid shaft servo motor 61 is fixedly installed on the upper side of the printing platform and on one side of the second driving member. A pulley 62 is fixedly installed on the driving shaft of the solid shaft servo motor, and a belt 63 is wrapped around the pulley and the second driving member. A belt groove is provided on the outer peripheral surface of the second driving member, and the belt is clamped in the belt groove. It can be understood that the pulley 62 can also be replaced with a gear, and meshing gears are provided on the second driving member to form a gear combination, and the solid shaft servo motor 61 drives the second driving member to rotate via the gear combination.

[0054] The second driving member has a second through-axis hole 661 , and the structure of the second through-axis hole is the same as that of the first through-axis hole. For details, please refer to the relevant description in Example 1 and will not be repeated here.

[0055] The reinforcing screw 40 freely passes through the second through-shaft hole and is screwed into the internal thread hole of the internal thread member. The reinforcing screw in this embodiment has the same structure as that in Embodiment 1. When the solid shaft servo motor drives the driving member to rotate, the protrusion can press against the tangent plane and drive the reinforcing screw to rotate. Under the restriction of the internal thread member, the reinforcing screw reciprocates in the vertical direction while rotating.

[0056] Example 3

[0057] This embodiment describes an enhanced 3D printing method, which is performed using the enhanced 3D printer in Implementation 1 or Implementation 2. The enhanced 3D printing method includes the following steps:

[0058] (1) After the 3D modeling of the model to be printed is completed, a cylindrical reinforcement area with a set diameter is calculated. Figure 3 ,exist Figure 3 In the model 30 shown, the area enclosed by the dotted line 91 is the reinforcement area. For clarity, the dotted line 91 extends upward to the model plate 23 and extends downward to the bottom of the model 30. For clarity, the model 30 is not provided with a section line.

[0059] The outer diameter of the reinforcing screw is 5 mm, the height of the thread of the reinforcing screw is about 0.49 mm, the set diameter of the reinforced area is 20 mm, and the reinforced area extends to an outer end face 35 of the model to be printed. The extension direction of the reinforced area is perpendicular to the outer end face, and the outer end face can be used as the starting face when printing the model.

[0060] (2) The model to be printed is printed with the outer end surface as the starting surface. During the printing process of the solidified layer of the model, a reinforcement hole 31 is formed in the reinforcement area. The reinforcement hole 31 is coaxially arranged with the reinforcing screw. The reinforcing screw is rotated to extend downward out of the guide rod hole, and the reinforcing screw is screwed into the reinforcement hole. During the printing interval between two adjacent solidified layers, the reinforcing screw remains stationary.

[0061] That is, after completing the printing of one solidified layer, the reinforcing screw is stopped from rotating before printing the next solidified layer, so that the reinforcing screw remains stationary to prevent the resin debris generated on the model from falling into the material trough when the reinforcing screw rotates. As a result, when the model descends, the model squeezes the resin debris and causes damage to the release film.

[0062] As printing progresses, the reinforcement holes extend as the model lengthens, and the reinforcement screws continue to screw downward.

[0063] In this embodiment, the inner diameter of the reinforcement hole is 4.6 mm, that is, the inner diameter of the reinforcement hole is less than the outer diameter of the reinforcement screw by about 0.82 thread heights of the reinforcement screw.

[0064] After each solidified layer is printed, the printing platform is lifted up, and after the solidified layer is separated from the release film of the material tank, the scraper system is started to move the scraper from one side of the material tank to the other side, pushing the solid particles deposited at the bottom of the material tank from the working area to the non-working area.

[0065] When the reinforcing screw is rotated in the reinforcement hole, some resin debris will inevitably be produced. These vertical debris will fall into the resin in the material tank. During the printing process of the fixed layer, when the reinforcing screw is rotated at the same time, the resin debris generated will not affect the printing. Before printing the next solidified layer, a scraper is used to push the resin debris that falls into the material tank from the working area to the non-working area, thereby avoiding damage to the release film and ensuring continuous printing.

[0066] (3) When printing is completed, the reinforcing screw is withdrawn from the printed model, and the lower end of the reinforcing screw is retracted into the guide rod hole.

[0067] In order to maintain the integrity of the model appearance, the lower end of the reinforced hole is a closed end 33. In this embodiment, the wall thickness H of the closed end is 1.5 mm.

[0068] In this embodiment, in order to prevent the reinforcing screw from touching the release film and causing damage to the release film during the printing process, the distance S between the lower end surface of the reinforcing screw and the to-be-printed and cured layer is 3 mm.

[0069] When the reinforcing screw is retracted into the guide rod hole, it will carry a small amount of resin. In order to prevent the resin from bonding the reinforcing screw to the inner wall of the guide rod hole, the resin in the guide rod hole needs to be cleaned after the model is printed.

Claims

1. A 3D printing platform with a reinforced screw, characterized in that: It comprises a printing platform detachably mounted on a connecting arm of a transmission mechanism, wherein the lower surface of the printing platform is formed as a working surface, and the connecting arm can drive the printing platform to reciprocate in a vertical direction; A guide rod hole is provided on the printing platform, the guide rod hole extends in the vertical direction and passes through the upper and lower sides of the printing platform, and an internal threaded member is detachably installed on the printing platform, the internal threaded member has an internal threaded hole coaxially arranged with the guide rod hole, the reinforcing screw is screwed in the internal threaded hole of the internal threaded member and can pass through the guide rod hole downward; a driving device for driving the reinforcing screw to rotate is also installed on the printing platform; The model is bonded to the printing platform, and a reinforced hole is formed in the model; under the drive of the driving device, the reinforcing screw can reciprocate in the vertical direction. When the reinforcing screw moves downward, it can extend downward from the guide rod hole and be screwed into the reinforced hole; when the reinforcing screw moves upward, it can withdraw from the model and retract the lower end of the reinforcing screw into the guide rod hole.

2. The 3D printing platform according to claim 1, characterized in that: The reinforcing screw is a hollow screw which opens downward.

3. The 3D printing platform according to claim 1, characterized in that: The transmission mechanism has a ball screw extending in a vertical direction, a connecting arm is engaged with the ball screw, a free end of the connecting arm is formed as a working end, and a printing platform is detachably mounted on the working end; One end of the connecting arm away from the ball screw has two clamping arms arranged at intervals in the horizontal direction. The two clamping arms extend in a direction away from the ball screw and are parallel to each other. A platform accommodating cavity is formed between the two clamping arms. The platform accommodating cavity has an opening facing away from the ball screw. Corresponding to each clamping arm, a clamping groove is respectively provided on two opposite sides of the printing platform. The printing platform is inserted into the platform accommodating cavity, and each clamping arm is inserted into the corresponding clamping groove. Each clamping arm is fixed to the printing platform by bolts, and the driving device is installed on the upper surface of the printing platform.

4. The 3D printing platform according to claim 3, characterized in that: The driving device includes a driving member and a solid shaft servo motor. The driving member is rotatably mounted on the upper side of the printing platform via a bearing. The driving member has an axial through hole. The reinforcing screw rod freely passes through the axial through hole. One side of the reinforcing screw rod has a cutting plane, and a protrusion is provided in the axial through hole. The solid shaft servo motor is fixedly mounted on the upper side of the printing platform and located on one side of the driving member. The output shaft of the solid shaft servo motor is connected to the driving member. When the solid shaft servo motor drives the driving member to rotate, the protrusion can be pressed against the cutting plane and drive the reinforcing screw rod to rotate. Under the restriction of the internal threaded member, the reinforcing screw rod reciprocates in the vertical direction while rotating.

5. The 3D printing platform according to claim 3, characterized in that: The driving device includes a driving member and a hollow shaft torque motor. The hollow shaft torque motor includes a stator and a mover rotatably arranged in the stator. The outer hollow shaft is fixed on the mover, and the inner hollow shaft is fixed on the outer hollow shaft. The outer hollow shaft, the inner hollow shaft and the guide rod hole are coaxially arranged. The driving member is detachably fixed on the inner hollow shaft. The driving member has a through-axis hole. The reinforcing screw rod freely passes through the through-axis hole. One side of the reinforcing screw rod has a cutting plane, and a radially outward protrusion is provided in the through-axis hole. When the mover drives the driving member to rotate, the protrusion can be pressed against the cutting plane and drive the reinforcing screw rod to rotate. Under the restriction of the internal threaded member, the reinforcing screw rod reciprocates in the vertical direction while rotating. The hollow shaft torque motor is a servo motor.

6. The 3D printing platform according to claim 1, characterized in that: The reinforcing screw is made of metal or alloy material.

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