Sinking separation type 3D printer and printing method thereof

Abstract

According to the sinking separation type 3D printer and the printing method thereof, a printing model is mainly borne by the printing screen plate and assisted by the supporting columns, compared with a traditional pull-up type, the supporting columns are thinned, the later polishing procedure is greatly reduced, the labor and time cost is reduced, and the surface of the model is smoother. The heat dissipation design is ingenious, the lower end of the printing screen assembly sinks into resin, heat is absorbed through heat conductivity of the resin, heat accumulation is avoided, it is ensured that an internal light-emitting device is stable, poor resin curing and poor interlayer adhesion are prevented, the service life is prolonged, and high-precision printing is guaranteed. The problem of resin slag falling is solved, slag particles fall into the trough resin under the action of gravity, a printing screen assembly is not polluted, a light-transmitting surface is clean, ultraviolet light is stably emitted, the printing success rate and quality are improved, and the rejection rate is reduced. The equipment further has an accurate program control and liquid level cooperation mechanism, the printing screen assembly and the printing screen plate are accurately controlled to move according to a pre-auditing program, and a foundation is built for high-quality 3D model output in combination with a liquid level observation window and a preset liquid level height.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a sinking type 3D printer and a printing method thereof. Background Art

[0002] In today's rapidly developing 3D printing field, photocuring 3D printing technology has received extensive attention and application due to its high-precision molding characteristics. Among them, a photocuring 3D printing device disclosed in the patent authorization announcement number CN 220314190 U is representative.

[0003] The device uses the top-down printing technology, and its structure is designed so that the light-emitting printing screen is placed at the bottom, and the printing stencil is placed at the top. In the actual printing process, the printing stencil will gradually move upwards, and with this movement, the printed model will solidify layer by layer on the printing stencil until the entire printing process is completed and the complete model is presented.

[0004] However, if we delve deeper into this pull-up printing technology, we will find that it has many drawbacks that are hard to ignore. On the one hand, since the model is hanging on the printing screen during the printing process, and considering that the model itself must have a certain weight, in order to ensure a stable and firm connection between the model and the printing screen, relatively thick connecting columns have to be printed. As a result, these thick connecting columns become a thorny problem in the subsequent model post-processing stage. The polishing process is not only time-consuming, but also requires a lot of manpower and energy, which greatly increases the production cost and time cost.

[0005] On the other hand, the characteristics of light-curing printing itself determine that it is easy to have slag falling during the printing process. The slag particles that fall off after curing fall onto the printing screen below under the action of gravity. As the printing operation continues, the slag particles continue to accumulate, which undoubtedly brings additional load to the printing screen. In the long run, it may even cause physical damage to the printing screen and affect its service life. At the same time, the slag particles attached to the screen surface will also interfere with the normal emission of printing light, which greatly reduces the light emission effect, and then leads to a decrease in printing accuracy and difficulty in ensuring model quality.

[0006] In summary, these problems of the existing top-up light-curing 3D printing technology urgently require a new solution to break through the current technical bottleneck and promote 3D printing technology to a higher level of development. Summary of the invention

[0007] In view of the problems pointed out in the background technology, the present invention proposes a sinking type 3D printer and a printing method thereof to solve the above technical problems.

[0008] The technical solution of the present invention is achieved in this way: A sinking type 3D printer comprises a material trough, a printing screen, and a printing screen assembly, wherein the printing screen is located on the upper side of the material trough, and the printing screen assembly is located on the upper side of the printing screen. Both the printing screen and the printing screen assembly can move up and down.

[0009] The present invention is further configured to include a device frame; A first slide rail is provided on the rear side of the equipment frame, the first slide rail is arranged in the up-down direction, a first movable frame is slidably connected to the first slide rail, and the printing screen assembly is fixedly arranged on the lower side of the first movable frame; The left and right sides of the equipment frame are respectively provided with second slide rails, the second slide rails are arranged in the up and down direction, the second slide rails are slidably connected with the second movable frame, and the left and right ends of the printing screen are respectively fixedly connected to the left and right second movable frames; The first slide rail and the second slide rail are respectively provided with screw mechanisms for driving the first movable frame and the second movable frame to move up and down; The upper ends of the first slide rail and the second slide rail are respectively provided with limit switches for limiting the upward movement of the first movable frame and the second movable frame to an extreme position.

[0010] The present invention is further configured such that the printing screen assembly comprises an LCD optical machine, a release film, and a fixed frame, wherein the LCD optical machine is fixedly connected to the first movable frame, the fixed frame is in the shape of a square frame, the LCD optical machine is located on the inner side of the fixed frame, a protruding fixing portion is provided on the side wall of the LCD optical machine, a connecting hole is provided on the fixing portion, a threaded hole corresponding to the connecting hole is provided on the upper side surface of the fixed frame, an adjusting bolt is connected between the connecting hole and the threaded hole, the release film is connected to the lower side of the fixed frame, the LCD optical machine is located on the upper side of the release film, the edge of the release film is sealed with the fixed frame, and a heat conducting structure is provided between the LCD optical machine (31) and the fixed frame (33).

[0011] The present invention is further configured such that the screw mechanism includes a screw rotatably arranged on the first slide rail and the second slide rail, the upper ends of the first slide rail and the second slide rail are provided with motors driving the screw to rotate, and the first mobile frame and the second mobile frame are respectively provided with nuts connected to the screw.

[0012] The present invention is further configured such that the upper ends of the first slide rail and the second slide rail are respectively provided with limit switches, and the first movable frame and the second movable frame are respectively provided with collision parts corresponding to the limit switches, and when the collision parts collide and contact with the limit switches, the limit switches send a signal to control the motor to stop working.

[0013] The present invention is further configured such that the first movable frame includes a first sliding block slidably connected to the first slide rail, the first sliding block is connected to a mounting plate, the mounting plate is horizontally arranged, and the printing screen assembly is fixedly arranged on the lower side of the mounting plate.

[0014] The present invention is further configured such that the second movable frame includes a second slider slidably connected to the second slide rail, and also includes an L-shaped connecting arm connecting the second slider and the printing screen, the upper end of the connecting arm is fixedly connected to the second slider, and the lower end of the connecting arm is fixedly connected to the printing screen.

[0015] The present invention is further configured such that the material trough is opened upward, and a liquid level observation window is provided on the side wall of the material trough.

[0016] A sinking type 3D printing method, comprising the above-mentioned 3D printer, comprises the following steps: Step (1), first let the machine reset to zero with one button, the printing screen assembly first rises and collides with the limit switch to return to zero, then the printing screen plate rises and collides with the limit switch to return to zero; Step (2), adding the resin material into the material tank; Step (3), the printing screen is lowered to below the liquid level in the material tank, and the distance between the upper side of the printing screen and the liquid level is 1-5 mm. This is the 0th layer position at the beginning of printing. Subsequently, the printing screen assembly is lowered to a position where the distance from the upper side of the printing screen is 0.1-0.3 mm; Step (4), printing the first layer, and the printing screen assembly begins to cure the first layer by ultraviolet light; Step (5), the printing screen moves downward 5 mm and then upward 4.9 mm; Step (6), printing the second layer, the printing screen assembly begins to cure the second layer by ultraviolet light; Step (7), repeat steps (5) and (6) until printing is completed; Step (8), when printing is finished, the printing screen assembly first rises and collides with the limit switch to return to zero, then the printing stencil rises and collides with the limit switch to return to zero, and then the printed model on the printing stencil is removed.

[0017] A sinking type 3D printing method, comprising the above-mentioned 3D printer, comprises the following steps: Step (1), first let the machine reset to zero with one button, the printing screen assembly first rises and collides with the limit switch to return to zero, then the printing screen plate rises and collides with the limit switch to return to zero; Step (2), adding the resin material into the material tank; Step (3), the printing screen is lowered to below the liquid level in the material tank, and the distance between the upper side of the printing screen and the liquid level is 1-5 mm. This is the 0th layer position at the beginning of printing. Subsequently, the printing screen assembly is lowered to a position where the distance from the upper side of the printing screen is 0.1-0.3 mm; Step (4), printing the first layer, and the printing screen assembly begins to cure the first layer by ultraviolet light; Step (5), the print screen assembly moves upward by 5 mm, and the print screen moves downward by 0.1 mm; Step (6), the print screen assembly moves downward 5 mm; Step (7), printing the second layer, the printing screen assembly begins to cure the second layer by ultraviolet light; Step (8), repeat step (5), step (6), and step (7) until printing is completed; Step (9), when printing is finished, the printing screen assembly first rises and collides with the limit switch to return to zero, then the printing stencil rises and collides with the limit switch to return to zero, and then the printed model on the printing stencil is removed.

[0018] By adopting the above technical solution, the beneficial effects of the present invention are as follows: First, a major breakthrough has been achieved in the support structure. The printed model is located on the upper side of the printing stencil, and is mainly supported by the printing stencil, with the support column only serving as an auxiliary. Compared with the traditional pull-up printing technology, the support column can be made thinner, which greatly reduces the post-polishing process, reduces manpower and time costs, improves the efficiency of model post-processing, and makes the model surface smoother and the details more perfect.

[0019] Secondly, the heat dissipation design is unique. The lower end of the print screen component is sunk into the resin, and the good thermal conductivity of the resin is cleverly used to absorb heat to achieve cooling and heat dissipation of the print screen component. This effectively avoids the accumulation of heat caused by ultraviolet light emission, ensures the stable performance of the light-emitting device inside the print screen component, and prevents problems such as poor resin curing and loose interlayer adhesion caused by excessive temperature. At the same time, it extends the service life of the print screen component and ensures long-term, high-precision printing operations.

[0020] Furthermore, the problem of resin slag has been properly solved. During the printing process, even if resin slag occurs, the slag particles will only fall into the resin in the material tank due to gravity, and will not fall on the printing screen component, ensuring that the light-transmitting surface of the printing screen component is clean and the ultraviolet light is stably and evenly emitted, greatly improving the success rate and quality of model printing and reducing the scrap rate.

[0021] Finally, the overall precise program control and liquid level coordination mechanism of the equipment ensures high precision and stability from the first layer printing to layer by layer stacking. The pre-set program accurately controls the movement of the printing screen component and the printing stencil, and cooperates with the liquid level observation window and the preset liquid level height, laying a solid foundation for the output of high-quality 3D models. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 It is a schematic diagram of the appearance structure of the present invention.

[0024] Figure 2 It is a schematic diagram of the internal structure of the present invention.

[0025] Figure 3 It is a structural schematic diagram of the printing screen driver of the present invention.

[0026] Figure 4 It is a schematic structural diagram of the second slide rail and the connecting arm of the present invention.

[0027] Figure 5 It is a schematic diagram of the exploded structure of the first slide rail and the first movable frame of the present invention.

[0028] Figure 6 It is a schematic diagram of the rear structure of the first slide rail and the first movable frame of the present invention.

[0029] Figure 7 It is a schematic diagram of the front structure of the first slide rail and the first movable frame of the present invention.

[0030] Figure 8 It is a schematic diagram of the exploded structure of the printing screen assembly of the present invention.

[0031] Fig. 9 It is a cross-sectional view of the printing screen assembly of the present invention.

[0032] Fig.10 Schematic diagram of the decomposition of the printing screen assembly of the present invention Figure 1 .

[0033] Fig.11 Schematic diagram of the decomposition of the printing screen assembly of the present invention Figure 2 .

[0034] Explanation of the numbers in the accompanying drawings: material trough 1, observation window 11, printing screen plate 2, printing screen assembly 3, LCD optical machine 31, release film 32, fixing frame 33, fixing part 34, connecting hole 35, threaded hole 36, adjusting bolt 37, equipment frame 4, first slide rail 51, first movable frame 52, first slider 53, mounting plate 54, second slide rail 61, second movable frame 62, second slider 63, connecting arm 64, limit switch 71, collision part 72, screw 81, motor 82, nut 83. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] For reference Figure 1-11 The present invention is described: Embodiment: A sinking type 3D printer comprises a material tank 1 (resin is contained in the material tank 1), a printing screen 2 (the printing screen 2 is used to carry the printed model), and a printing screen assembly 3 (the printing screen assembly 3 emits ultraviolet light to solidify the resin layer by layer and print it on the printing screen 2). The printing screen 2 is located on the upper side of the material tank 1, and the printing screen assembly 3 is located on the upper side of the printing screen 2. Both the printing screen 2 and the printing screen assembly 3 can move up and down.

[0037] When performing 3D printing, the print stencil 2 is lowered into the material tank 1, and the print stencil 2 is located below the resin liquid surface. The print screen assembly 3 is also lowered into the material tank 1, and a portion of the lower end of the print screen assembly 3 is immersed in the resin. The distance between the lower side of the print screen assembly 3 and the upper side of the print stencil 2 is 0.1 mm, which is the thickness of one layer of printing. After completing one print, the print stencil 2 moves downward by 5 mm for release, and then moves upward by 4.9 mm to prepare for the next print. This process is repeated until the printing of the 3D model is completed.

[0038] In traditional pull-up 3D printing technology, such as the device with patent authorization announcement number CN220314190U, since the model is hung below the printing screen, the weight of the model itself is entirely supported by the connection between it and the printing screen. In order to ensure the stability of the connection, thicker connecting columns have to be used. However, the sinking 3D printer of the present invention has completely changed this force mode. The printed model is on the upper side of the printing screen, and the printing screen becomes the main load-bearing component, using its own structural strength and stability to provide solid support for the model. At this time, the printed support column only needs to play an auxiliary support role and does not need to bear most of the weight of the model, so it can be designed to be thinner. This design of thinning the support column brings significant benefits. In the post-processing stage after the model is printed, the workload of the polishing process is greatly reduced. Originally, when faced with thick connecting columns, grinders needed to spend a lot of time using professional tools to grind off the excess parts bit by bit. In addition, it is difficult to grind thick connecting columns and it is easy to damage the delicate parts of the model. Now, the slender support columns are more convenient and efficient to grind, which not only shortens the grinding time and reduces labor costs, but also improves the overall quality of model post-processing, making the model surface smoother and closer to design expectations.

[0039] The print screen component 3 undertakes the key task of emitting ultraviolet light to cure the resin during the 3D printing process. The emission of ultraviolet light is accompanied by the generation of heat. If the heat cannot be dissipated in time, the temperature of the print screen component 3 will continue to rise. On the one hand, excessively high temperature may affect the performance stability of the internal light-emitting device, resulting in deviations in parameters such as ultraviolet light wavelength and intensity, which in turn affects the resin curing effect, causing problems such as local poor curing and loose interlayer adhesion in the model; on the other hand, long-term high temperature environment will also accelerate the aging of the outer shell and internal components of the print screen component 3, shortening its service life. The present invention cleverly uses the physical properties of the resin to solve the heat dissipation problem. When the print screen component 3 descends into the trough 1, its lower end sinks into the resin, and the resin, as a liquid, has good thermal conductivity. The heat generated by the print screen component 3 can be quickly transferred to the resin and absorbed and dispersed by a large amount of surrounding resin liquid. Compared with traditional cooling methods such as air cooling and water cooling, this method of using the working medium - resin for heat dissipation is more direct and efficient. It does not require the installation of additional complex heat dissipation devices, which not only saves equipment costs and internal space, but also ensures that the print screen component 3 always maintains a relatively stable operating temperature during long-term continuous printing, ensuring that the printing operation continues to be carried out with high precision and high quality.

[0040] During the photocuring printing process, resin slag is a common problem. In the previous pull-up printing technology, since the printing screen is located at the bottom, the slag will fall directly onto the printing screen. With the accumulation of slag particles, the light transmittance of the printing screen is seriously affected, the emission of ultraviolet light is blocked, and the light intensity is greatly attenuated when passing through the area covered by the slag particles, resulting in incomplete curing of the resin at the corresponding position and defects in the model; moreover, the accumulation of slag particles will also increase the load on the printing screen, which may cause scratches and wear on the screen surface for a long time, reduce the screen clarity, and even damage the screen. The sinking type design of the present invention fundamentally changes this situation. The printing screen assembly 3 is located above the printing screen 2, and during the printing process, even if the resin slags, the slag particles will only fall downward due to gravity and eventually fall into the resin in the material trough 1, and will not fall on the printing screen assembly 3. This ensures that the light-transmitting surface of the printing screen assembly 3 always remains clean, and the ultraviolet light can be emitted stably and evenly, providing reliable lighting conditions for resin curing, so that each layer of resin can be accurately cured, greatly improving the success rate and quality of model printing, reducing the model scrap rate caused by slag problems, reducing production costs, and improving production efficiency.

[0041] It also includes a device frame 4; the device frame 4 serves as a supporting skeleton of the entire sinking type 3D printer and plays an important role in carrying and fixing various key components.

[0042] The first slide rail 51 is carefully arranged on the rear side of the equipment frame 4. The slide rail is strictly arranged in the up and down direction. This vertical design provides a guide reference for the subsequent precise movement of the printing screen component 3. The first slide rail 51 and the first mobile frame 52 are connected by sliding, so that the first mobile frame 52 can slide up and down smoothly along the slide rail. The printing screen component 3 is firmly fixed on the lower side of the first mobile frame 52. In this way, when the height position of the printing screen component 3 needs to be adjusted, it can be accurately achieved by sliding the first mobile frame 52 on the first slide rail 51. For example, when printing models of different heights or performing initialization calibration before printing, adjusting the layer spacing during printing, etc., this structural design can ensure that the printing screen component 3 reaches the specified position quickly and accurately, laying the foundation for high-quality printing.

[0043] At the same time, the left and right sides of the equipment frame 4 are respectively equipped with second slide rails 61, which also extend in the up and down direction. The left-right symmetrical design not only ensures the stability of the structure, but also provides reliable support for the smooth movement of the printing screen 2. The left and right ends of the printing screen 2 are firmly fixedly connected to the left and right second movable frames 62, respectively, so that when the second movable frame 62 slides up and down along the second slide rail 61, it can drive the printing screen 2 to achieve synchronous movement. During the 3D printing process, the printing screen 2 needs to be frequently raised and lowered to complete key actions such as resin immersion, mold separation, and layer switching. The combined structure of the second slide rail 61 and the second movable frame 62 ensures that these actions can be performed stably and efficiently, avoiding problems such as shaking and offset of the printing screen 2 during movement, thereby ensuring the accuracy and quality of the printed model.

[0044] The first slide rail 51 and the second slide rail 61 are respectively provided with a screw mechanism for driving the first mobile frame 52 and the second mobile frame 62 to move up and down; the screw mechanisms respectively provided on the first slide rail 51 and the second slide rail 61 are the core power sources for realizing the precise movement control of the printing screen assembly 3 and the printing screen plate 2. The screw mechanism is composed of components such as a screw, a nut and a driving motor. When the driving motor is running, the screw rotates accordingly, and the nut moves linearly along the thread direction of the screw. For the screw mechanism connected to the first mobile frame 52, the linear motion of the nut is converted into the up and down sliding of the first mobile frame 52 on the first slide rail 51, thereby driving the printing screen assembly 3 to move precisely. Similarly, the screw mechanism connected to the second mobile frame 62 can drive the printing screen plate 2 to rise and fall according to preset requirements. This screw mechanism driving mode has significant advantages over other driving forms, such as simple chain drive or belt drive. It can provide higher positioning accuracy, because the thread pitch of the screw can be accurately designed and controlled, so that the step length of each movement is accurately controllable, meeting the stringent requirements of 3D printing for layer thickness, position accuracy, etc. Moreover, the screw mechanism has good self-locking properties. When the motor stops running, it can effectively prevent the printing screen assembly 3 and the printing screen plate 2 from accidentally moving due to external forces, further ensuring the stability and reliability of the printing process.

[0045] Limit switches 71 for limiting the upward movement of the first moving frame 52 and the second moving frame 62 to their extreme positions are respectively disposed at the upper ends of the first slide rail 51 and the second slide rail 61 .

[0046] The printing screen assembly 3 includes an LCD light machine 31, a release film 32, and a fixed frame 33. The LCD light machine 31 is fixedly connected to the first mobile frame 52. The fixed frame 33 is in a square shape, and the LCD light machine 31 is located inside the fixed frame 33. As a crucial part in the 3D printing process, the printing screen assembly 3 has a sophisticated structural design and clear functions. It is mainly composed of an LCD light machine 31, a release film 32, and a fixed frame 33. As a core light-emitting component, the LCD light machine 31 is responsible for emitting ultraviolet light to cure the resin. It is fixedly connected to the first mobile frame 52 to ensure that it can move accurately with the first mobile frame 52 during the operation of the equipment, meeting the requirements of the illumination position in different printing stages. The fixed frame 33 is in a square shape, which provides a stable protection and support frame for the internal LCD light machine 31, so that it is in a relatively stable working environment. The LCD light machine 31 is located inside the fixed frame 33. This layout not only ensures the safety of the LCD light machine 31, prevents it from being disturbed by external collisions and other factors, but also facilitates the coordinated operation of subsequent components.

[0047] The four side walls of the LCD optical machine 31 (the LCD optical machine 31 is square) are respectively provided with protruding fixing parts 34, and the fixing parts 34 are provided with connecting holes 35. The upper side surface of the fixing frame 33 is provided with threaded holes 36 corresponding to the connecting holes 35, and adjusting bolts 37 are connected in the connecting holes 35 and the threaded holes 36. The release film 32 is connected to the lower side of the fixing frame 33, and the LCD optical machine 31 is located on the upper side of the release film 32. The edge of the release film 32 forms a sealed connection with the fixing frame 33. The sealed connection here allows the printing screen assembly 3 to sink into the liquid resin.

[0048] The lower end of the printed screen assembly is sunk into the resin, and the resin's good thermal conductivity is cleverly used to absorb heat, thereby achieving cooling and heat dissipation of the printed screen assembly. The heat emitted by the LCD optical machine 31 is transferred to the fixed frame 33 through the thermal conductive structure (the thermal conductive structure is made of a material with good thermal transfer performance, and the thermal conductive structure is arranged in contact with the fixed frame 33 and the LCD optical machine 31). The lower end of the fixed frame 33 is immersed in the resin. The fixed frame 33 is annular, and the lower end of the fixed frame 33 is sealed by the release film 32, so that the resin does not enter the inner side of the fixed frame 33. The depth of the lower end of the fixed frame 33 immersed in the resin can be adjusted as needed.

[0049] The four side walls of the LCD optical machine 31 are respectively provided with protruding fixing parts 34, which is a unique design. The connection hole 35 provided on the fixing part 34 corresponds to the threaded hole 36 on the upper side of the fixing frame 33, and the two are connected by an adjusting bolt 37. This connection method gives the printing screen assembly 3 high adjustability. In the actual production and use process, due to factors such as equipment assembly accuracy, component wear and slight deformation after long-term use, the release film 32 may tilt and cannot maintain an ideal horizontal state. By rotating the adjusting bolt 37, the height position of the fixing frame 33 relative to the LCD optical machine 31 can be accurately fine-tuned. The operator can monitor the levelness of the release film 32 in real time based on a level measurement tool, such as a high-precision level, and fine-tune the adjusting bolt 37 accordingly to ensure that the release film 32 can maintain a level at any time, thereby ensuring the stability and consistency of the printing quality.

[0050] The release film 32 is connected to the lower side of the fixed frame 33, and the LCD light machine 31 is located on the upper side of the release film 32, and the three are closely matched. The edge of the release film 32 forms a sealed connection with the fixed frame 33. This sealing design is a key link in realizing sinking printing. During the printing process, when the printing screen component 3 needs to sink into the material tank 1 and its lower end is immersed in liquid resin, the sealed connection can effectively prevent the resin from penetrating from the edge gap, avoid the resin from contacting the LCD light machine 31 and other internal sensitive components, and prevent the short circuit, corrosion or affect the normal light emission of the LCD light machine 31 caused by the intrusion of resin. At the same time, the sealed connection ensures that a relatively independent and clean space is formed inside the printing screen component 3, so that the ultraviolet light emitted by the LCD light machine 31 can stably and evenly penetrate the release film 32 to irradiate the resin below, providing reliable guarantee for the precise curing of the resin layer by layer, greatly improving the success rate and model quality of 3D printing.

[0051] The screw mechanism is a key part that drives the printing screen assembly 3 and the printing screen plate 2 to move accurately. Its composition structure is rigorous and its design is scientific. It mainly includes a screw 81 that is rotatably arranged on the first slide rail 51 and the second slide rail 61. The screw 81 is a core transmission component that is arranged along the longitudinal direction of the slide rail and can be flexibly rotated under power drive. The upper ends of the first slide rail 51 and the second slide rail 61 are carefully equipped with a motor 82 that drives the screw 81 to rotate. The motor 82 serves as a power source and provides stable and reliable power support for the rotation of the screw 81. At the same time, the first mobile frame 52 and the second mobile frame 62 are respectively provided with nuts 83 connected to the screw 81. The nut 83 is tightly engaged with the thread of the screw 81. This matching method constitutes the basic transmission link of the screw mechanism.

[0052] The upper ends of the first slide rail 51 and the second slide rail 61 are respectively provided with limit switches 71, and the first moving frame 52 and the second moving frame 62 are respectively provided with collision parts 72 corresponding to the limit switches 71. When the collision parts 72 collide with the limit switches 71, the limit switches 71 send a signal to stop the control motor 82. The machine is reset to zero with one key. The printing screen assembly 3 first rises and collides with the limit switch 71 to return to zero, and then the printing screen plate 2 rises and collides with the limit switch 71 to return to zero.

[0053] The limit switch 71 provided at the upper end of the first slide rail 51 and the second slide rail 61 is a key line of defense to ensure the safe and accurate operation of the equipment. Correspondingly, the first mobile frame 52 and the second mobile frame 62 are respectively provided with a collision part 72. During the normal operation of the equipment, the printing screen assembly 3 moves along the first slide rail 51 with the first mobile frame 52, and the printing screen plate 2 moves along the second slide rail 61 with the second mobile frame 62. However, due to possible emergencies such as control system failure, program error or mechanical component abnormality, the mobile frame has the risk of moving upward beyond the normal range. When this happens, the collision part 72 on the mobile frame will collide with the corresponding limit switch 71. As a sensitive sensing device, the limit switch 71 immediately triggers and sends a signal to stop the control motor 82 once the collision action is detected. This process is completed instantly, which can effectively prevent the mobile frame from continuing to move upward, avoid it from hitting the equipment frame 4 or other components, prevent equipment damage, ensure the integrity of the overall structure of the equipment and subsequent normal use, and greatly reduce the maintenance cost and downtime caused by unexpected situations.

[0054] The one-button reset to zero operation of the machine is essential for equipment maintenance, initial calibration, and ensuring the consistency of each printing task. When performing this operation, the print screen assembly 3 starts the rising action first. Driven by the motor 82 and the screw mechanism, the first movable frame 52 drives the print screen assembly 3 to rise steadily along the first slide rail 51 until the collision portion 72 collides with the limit switch 71. This collision is instantly sensed by the limit switch 71, and the system records and calibrates the position of the print screen assembly 3 at this time as the zero position, completing the zeroing operation of the print screen assembly 3. Then, the print screen 2 begins to rise. Also under the action of the second slide rail 61 and related driving components, the second movable frame 62 drives the print screen 2 to move upward until its collision portion 72 collides with the corresponding limit switch 71. The system records this position again and sets it as the zero point, realizing the zeroing of the print screen 2. Through this one-touch reset to zero operation, the device can return to a uniform and precise initial state before starting each printing task, effectively eliminating the cumulative errors that may have occurred during the previous printing process, ensuring the accuracy and quality stability of subsequent printed models, and providing solid guarantees for high-quality and efficient 3D printing production.

[0055] The first mobile frame 52 includes a first slider 53 slidably connected to the first slide rail 51, a mounting plate 54 is connected to the first slider 53, the mounting plate 54 is horizontally arranged, and the print screen assembly 3 is fixedly arranged on the lower side of the mounting plate 54. The design of the first mobile frame 52 is ingenious, aiming to ensure that the print screen assembly 3 can move stably and accurately. It is mainly composed of the first slider 53 slidably connected to the first slide rail 51 to form a basic sliding component. The first slider 53 can fit tightly with the first slide rail 51 by virtue of its precise processing technology, while maintaining an extremely low friction coefficient, so that it is smooth and stable during the movement process, effectively reducing the energy loss and position deviation caused by friction. A horizontally arranged mounting plate 54 is connected to the first slider 53. The mounting plate 54 serves as a key platform for carrying the print screen assembly 3, and its horizontality is strictly controlled. The printing screen assembly 3 is fixedly arranged on the lower side of the mounting plate 54. This stable connection method ensures that the printing screen assembly 3 will not shake, tilt, or have other problems during various movements such as lifting, lowering, and translation with the first movable frame 52, thereby providing a solid guarantee for the stable emission and precise irradiation of ultraviolet light, thereby ensuring the accuracy and quality of the curing of each layer of the 3D printed model.

[0056] The second mobile frame 62 includes a second slider 63 slidably connected to the second slide rail 61, and also includes an L-shaped connecting arm 64 connecting the second slider 63 and the printing screen 2, the upper end of the connecting arm 64 is fixedly connected to the second slider 63, and the lower end of the connecting arm 64 is fixedly connected to the printing screen 2. The structural design of the second mobile frame 62 is closely centered on the movement requirements of the printing screen 2. It includes a second slider 63 slidably connected to the second slide rail 61, and the second slider 63 also has high-precision sliding performance to ensure the smooth lifting and lowering of the printing screen 2 in the vertical direction. In order to achieve the effective connection between the printing screen 2 and the second slider 63, an L-shaped connecting arm 64 is used. The upper end of the L-shaped connecting arm 64 is fixedly connected to the second slider 63 to ensure the stable transmission of force, and the lower end is fixedly connected to the printing screen 2, so that the printing screen 2 can move accurately following the movement of the second slider 63. This L-shaped structural design cleverly avoids spatial interference with other components inside the equipment. At the same time, in terms of mechanical structure, it can evenly disperse the force on the printing stencil 2 during the lifting process, avoiding deformation of the printing stencil 2 due to local uneven force, and ensuring the reliability and stability of the printing stencil 2 during frequent operations such as resin immersion and mold separation, providing strong support for the smooth progress of 3D printing.

[0057] The material trough 1 is opened upward, and a liquid level observation window 11 is provided on the side wall of the material trough 1. The material trough 1 is opened upward, and this design facilitates the addition and replacement of resin. The operator can directly inject the resin into the material trough 1 without the help of complex tools or special angles, which improves the efficiency of daily maintenance and material replenishment. At the same time, a liquid level observation window 11 is provided on the side wall of the material trough 1. The liquid level observation window 11 is usually made of a transparent material, such as a high-strength acrylic plate, and has good light transmittance and corrosion resistance. Through the liquid level observation window 11, the operator can observe the liquid level of the resin in the material trough 1 in real time and intuitively, and grasp the consumption of the resin in time, so as to replenish the resin in time when the liquid level is too low, avoid printing interruption or model quality problems due to insufficient resin, ensure the continuity and stability of the 3D printing process, and improve the overall production efficiency.

[0058] A sinking type 3D printing method, comprising the above-mentioned 3D printer, comprises the following steps: Step 1: First, let the machine reset to zero with one key. The print screen assembly 3 first rises and collides with the limit switch 71 to return to zero, and then the print screen 2 rises and collides with the limit switch 71 to return to zero. Step 1 is the starting preparation stage of the entire printing process and is very important. To perform the machine reset to zero with one key, first, the print screen assembly 3 is driven by the motor and the screw mechanism to rise steadily along the first slide rail 51. At this time, the first slider 53 of the first mobile frame 52 moves smoothly, and the mounting plate 54 drives the print screen assembly 3 to move upward accurately until its collision part 72 collides with the limit switch 71. The system immediately records this position as the zero point and completes the zero calibration of the print screen assembly 3. Next, the print screen 2 starts the rising action, and the second slider 63 of the second mobile frame 62 slides along the second slide rail 61, driving the print screen 2 upward through the L-shaped connecting arm 64. Similarly, at the moment when the collision part 72 collides with the limit switch 71, the system completes the zero setting of the print screen 2. This step effectively eliminates the position deviation that may remain after the device was last used, laying the foundation for subsequent high-precision printing.

[0059] Step 2, add the resin material to the material tank 1; Step 2 is simple to operate but indispensable. Add the resin material to the material tank 1. Thanks to the upward opening design of the material tank 1, the operator can easily pour the resin directly without additional auxiliary tools or complicated operations. At the same time, through the liquid level observation window 11 on the side wall of the material tank 1, the resin injection amount is observed in real time to ensure that the amount of resin added meets the requirements of this printing task, avoiding waste caused by excessive resin addition and preventing too little from affecting the printing process, ensuring the smooth start of subsequent printing.

[0060] Step 3, the printing screen 2 is lowered to below the liquid level in the material tank 1, and the distance between the upper side of the printing screen 2 and the liquid level is 1-5mm, which is the 0-layer position at the beginning of printing. Subsequently, the printing screen assembly 3 is lowered to a position 0.1-0.3mm away from the upper side of the printing screen 2; Entering step 3, the printing screen 2 begins to descend under the action of the driving mechanism, and accurately enters below the liquid level in the material tank 1, and maintains a distance of 1-5mm from the liquid level. This distance has been optimized through repeated tests, which can not only ensure that the printing screen 2 is quickly infiltrated with resin, but also prevent the fluctuation of resin due to excessive immersion from affecting the printing accuracy of the first layer. This position is set as the 0-layer position at the beginning of printing. Subsequently, the printing screen assembly 3 descends along the slide rail until the distance from the upper side of the printing screen 2 is within the range of 0.1-0.3mm. This extremely small spacing is the key to ensure that ultraviolet light can efficiently penetrate and accurately solidify the first layer of resin, providing an accurate starting reference for subsequent layer-by-layer printing.

[0061] Step 4: Print the first layer, and the printing screen component 3 begins to cure the first layer by ultraviolet light; Step 4 starts the substantial printing process. The LCD light machine 31 in the printing screen component 3 is started, emitting high-intensity ultraviolet light, and the light is evenly irradiated on the resin below that is close to the printing screen 2 through the release film 32. With the precise optical structure and stable luminous performance of the LCD light machine 31, and the good light transmittance and release characteristics of the release film 32, the first layer of resin is quickly and evenly cured under ultraviolet light, forming the first layer of the basic structure of the model, whose accuracy and quality are directly related to the success or failure of the entire model.

[0062] Step 5, the printing screen 2 moves downward 5mm and then upward 4.9mm; after the first layer of printing is completed, enter step 5, the printing screen 2 moves downward 5mm according to the preset program. This action realizes the effective separation of the first layer of cured model and the release film 32 to avoid adhesion; then it moves upward 4.9mm and accurately resets to a position very close to the first layer of cured model, preparing for the next layer of resin curing to ensure close bonding between layers and natural transition.

[0063] Step 6: Print the second layer, and the printing screen assembly 3 begins to cure the second layer by ultraviolet light; Step 7: Repeat steps 5 and 6 until printing is completed; steps 6 and 7 constitute a cyclic printing process. Each time steps 5 and 6 are repeated, the printing screen component 3 continuously emits ultraviolet light to solidify the resin layer by layer, and the printing screen 2 accurately completes the release and reset actions. Under strict program control and the coordinated operation of mechanical components, the model is steadily built layer by layer until the preset number of printing layers is reached, completing the physical formation of the entire model.

[0064] Step 8, end printing, first, the printing screen assembly 3 rises, repeats the initial zeroing action, hits the limit switch 71 to achieve zeroing calibration, and ensures that the device returns to the initial state. Then, the printing stencil 2 rises and also returns to zero. Finally, the operator can easily remove the printed model from the printing stencil 2, completing the entire 3D printing process, and the model can enter the subsequent post-processing process.

[0065] A sinking type 3D printing method, comprising the above-mentioned 3D printer, comprises the following steps: Step 1, first let the machine reset to zero with one button, the print screen assembly 3 first rises and collides with the limit switch 71 to return to zero, and then the print screen plate 2 rises and collides with the limit switch 71 to return to zero; Step 1 is the starting preparation link of the entire printing process and plays a key calibration role. Start the machine's one-button reset to zero operation. First, the print screen assembly 3 rises smoothly along the first slide rail 51 under the operation of the motor-driven screw mechanism. At this time, the first slider 53 of the first movable frame 52, with its high-precision sliding performance, smoothly drives the mounting plate 54 and the print screen assembly 3 fixed on the lower side of the mounting plate 54 to move upward accurately until its collision part 72 collides with the limit switch 71. The system instantly captures this signal and accurately records the position as the zero point, completing the zero calibration of the print screen assembly 3, ensuring that it returns to the initial standard position, and providing an accurate starting reference for subsequent printing. Next, the printing screen 2 starts to rise, and the second slider 63 of the second movable frame 62 slides steadily along the second slide rail 61, and the printing screen 2 is powerfully driven upward through the L-shaped connecting arm 64. Similarly, at the moment when the collision part 72 collides with the limit switch 71, the system completes the zeroing setting of the printing screen 2, eliminating the position deviation that may have existed before, laying a solid foundation for high-precision printing.

[0066] Step 2, adding the resin material into the material tank 1; Step 3, the printing screen 2 is lowered to below the liquid level in the material tank 1, and the distance between the upper side of the printing screen 2 and the liquid level is 1-5mm. This is the 0th layer position at the beginning of printing. Subsequently, the printing screen assembly 3 is lowered to a position where the distance from the upper side of the printing screen 2 is 0.1-0.3mm; Step 4: Print the first layer, and the printing screen assembly 3 begins to cure the first layer by ultraviolet light; Step 5, the printing screen assembly 3 moves upward by 5mm, and the printing stencil 2 moves downward by 0.1mm; after the first layer of printing is completed, enter step 5, at which time the printing process undergoes a key change. The printing screen assembly 3 moves upward by 5mm according to the preset program, achieving the initial separation of the first layer of solidified model and the release film 32 to prevent adhesion; at the same time, the printing stencil 2 moves downward by 0.1mm, preparing for the next step of printing.

[0067] Step 6: Move the print screen assembly 3 downward by 5 mm and accurately return it to the appropriate distance above the first layer of the cured model to further optimize the interlayer lighting and connection conditions, making the interlayer bonding tighter and more natural, creating an ideal environment for the next layer of resin curing, and consolidating the structural coherence and stability of the model during the layer-by-layer construction process.

[0068] Step 7, printing the second layer, the printing screen assembly 3 starts to cure the second layer by ultraviolet light; Step 8. Repeat steps 5, 6, and 7 until printing is completed; Step 9, finish printing, the printing screen assembly 3 first rises and collides with the limit switch 71 to return to zero, then the printing screen plate 2 rises and collides with the limit switch 71 to return to zero, and then the printed model on the printing screen plate 2 is removed.

[0069] The movement of the print screen assembly 3 and the print screen 2 is precisely controlled by a pre-set program. The movement accuracy of the print screen assembly 3 and the print screen 2 plays a decisive role in the success or failure of 3D printing. Throughout the printing process, their movement is controlled by a pre-set program, which is developed based on in-depth research and repeated testing of 3D printing model structure, precision requirements, and mechanical component performance. Taking the print screen assembly 3 as an example, when the motor drives the screw mechanism to operate, the motor receives precise instructions from the program, controls the rotation angle and speed of the screw, and then determines the sliding distance and rhythm of the first slider 53 of the first moving frame 52 on the first slide rail 51. Similarly, for the print screen 2, the movement of the second slider 63 of the second moving frame 62 along the second slide rail 61 also strictly follows the program settings. In step 3, the depth to which the printing screen 2 descends below the liquid surface of the material tank 1 must be precisely controlled to maintain a distance of 1-5mm from the liquid surface. This tiny adjustment range is the key to ensuring the accuracy of the first layer of printing. One millimeter more may cause resin fluctuations to interfere with curing, and one millimeter less may prevent the resin from being quickly infiltrated to start the first layer of construction. The printing screen assembly 3 descends to a position 0.1-0.3mm from the upper side of the printing screen 2, and also relies on the coordinated command of the motor, screw rod, slider and other components by the program to ensure that the ultraviolet light emission distance is just right to achieve accurate curing of the first layer of resin. This precise program control runs through the entire printing process. For example, in the inter-layer switching steps, the up and down movement of the printing screen assembly 3 and the slight displacement of the printing screen 2 are all carried out in an orderly manner under program monitoring to ensure the accuracy and stability of the layered model.

[0070] The liquid level observation window 11 is provided with a scale. Before each printing, the liquid level of the resin is added to a preset liquid level height. The position of the printing screen component 3 and the printing stencil 2 entering the resin in step 3 is controlled in conjunction with a preset program. The carefully set scale on the liquid level observation window 11 provides an intuitive basis for resin liquid level control. Before each printing, the operator needs to add the liquid level of the resin to a precise height according to the preset program requirements. This preset liquid level height is not set arbitrarily, it is closely related to the initial entry position of the printing screen component 3 and the printing stencil 2 in step 3. The program calculates the appropriate liquid level height based on factors such as model size, resin properties, and mechanical structure of the equipment. When the liquid level accurately reaches the set value, the printing stencil 2 descends to a specific depth below the liquid surface, which can ensure that the first layer of resin is sufficient and evenly distributed, avoiding insufficient resin that cannot be molded due to too low a liquid level, or waste and printing interference caused by too high a liquid level. At the same time, in accordance with the liquid level, after the printing screen assembly 3 drops to the corresponding position, the ultraviolet light penetrates the release film 32 to act on the resin to the best effect, ensuring that the first layer of curing reaches high-precision standards from the beginning. In subsequent printing cycles, the stable liquid level also provides consistent conditions for the curing of each layer of resin, ensuring the uniformity and reliability of the overall quality of the model, making the entire 3D printing process like a precision manufacturing process, with each step being accurate and correct, and ultimately outputting a high-quality 3D model.

[0071] The release film 32 is disposed on the lower side of the fixing frame 33 , and the release film 32 is fixed to the fixing frame 33 via a circular ring.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A sinking type 3D printer, comprising a material trough (1), a printing screen (2), and a printing screen assembly (3), characterized in that: The printing screen plate (2) is located on the upper side of the material trough (1), and the printing screen assembly (3) is located on the upper side of the printing screen plate (2). Both the printing screen plate (2) and the printing screen assembly (3) can move up and down.

2. A sinking type 3D printer according to claim 1, characterized in that: including an equipment frame (4); A first slide rail (51) is provided on the rear side of the equipment frame (4), the first slide rail (51) is arranged in the up-down direction, a first movable frame (52) is slidably connected to the first slide rail (51), and the printing screen assembly (3) is fixedly arranged on the lower side of the first movable frame (52); The left and right sides of the equipment frame (4) are respectively provided with second slide rails (61), the second slide rails (61) are arranged in the up-down direction, and the second slide rails (61) are slidably connected to the second movable frames (62), and the left and right ends of the printing screen (2) are respectively fixedly connected to the left and right second movable frames (62); The first slide rail (51) and the second slide rail (61) are respectively provided with screw mechanisms for driving the first movable frame (52) and the second movable frame (62) to move up and down; The upper ends of the first slide rail (51) and the second slide rail (61) are respectively provided with limit switches (71) for limiting the upward movement of the first movable frame (52) and the second movable frame (62) to an extreme position.

3. A sinking type 3D printer according to claim 2, characterized in that: The printing screen assembly (3) comprises an LCD optical machine (31), a release film (32), and a fixed frame (33). The LCD optical machine (31) is fixedly connected to the first movable frame (52). The fixed frame (33) is in the shape of a square frame. The LCD optical machine (31) is located on the inner side of the fixed frame (33). A protruding fixing portion (34) is provided on the side wall of the LCD optical machine (31). A connecting hole (35) is provided on the fixing portion (34). A threaded hole (36) corresponding to the connecting hole (35) is provided on the upper side of the fixed frame (33). Adjustment bolts (37) are connected in the connecting hole (35) and the threaded hole (36). The release film (32) is connected to the lower side of the fixed frame (33). The LCD optical machine (31) is located on the upper side of the release film (32). The edge of the release film (32) forms a sealed connection with the fixed frame (33). A heat conducting structure is provided between the LCD optical machine (31) and the fixed frame (33).

4. A sinking type 3D printer according to claim 2, characterized in that: The screw mechanism comprises a screw rod (81) rotatably arranged on the first slide rail (51) and the second slide rail (61); a motor (82) for driving the screw rod (81) to rotate is provided at the upper end of the first slide rail (51) and the second slide rail (61); and nuts (83) connected to the screw rod (81) are respectively provided on the first movable frame (52) and the second movable frame (62).

5. A sinking type 3D printer according to claim 2, characterized in that: The upper ends of the first slide rail (51) and the second slide rail (61) are respectively provided with limit switches (71); the first movable frame (52) and the second movable frame (62) are respectively provided with collision parts (72) corresponding to the limit switches (71); when the collision parts (72) collide and contact with the limit switches (71), the limit switches (71) send a signal to control the motor (82) to stop working.

6. A sinking type 3D printer according to claim 2, characterized in that: The first movable frame (52) comprises a first sliding block (53) slidably connected to the first sliding rail (51), the first sliding block (53) being connected to a mounting plate (54), the mounting plate (54) being arranged horizontally, and the printing screen assembly (3) being fixedly arranged on the lower side of the mounting plate (54).

7. A sinking type 3D printer according to claim 2, characterized in that: The second movable frame (62) includes a second slider (63) slidably connected to the second slide rail (61), and also includes an L-shaped connecting arm (64) connecting the second slider (63) and the printing screen (2), the upper end of the connecting arm (64) is fixedly connected to the second slider (63), and the lower end of the connecting arm (64) is fixedly connected to the printing screen (2).

8. The sinking type 3D printer according to claim 2, characterized in that: The material trough (1) is arranged to open upward, and a liquid level observation window (11) is provided on the side wall of the material trough (1).

9. A sinking type 3D printing method, comprising the 3D printer according to any one of claims 2 to 8, characterized in that: The steps include: Step (1), firstly, the machine is reset to zero by one key, the printing screen assembly (3) first rises and collides with the limit switch (71) to return to zero, and then the printing screen plate (2) rises and collides with the limit switch (71) to return to zero; Step (2), adding the resin material into the material tank (1); Step (3), the printing screen (2) is lowered to below the liquid level in the material tank (1), and the distance between the upper side of the printing screen (2) and the liquid level is 1-5 mm, which is the 0th layer position at the beginning of printing. Subsequently, the printing screen assembly (3) is lowered to a position where the distance from the upper side of the printing screen (2) is 0.1-0.3 mm; Step (4), printing the first layer, the printing screen assembly (3) begins to cure the first layer by ultraviolet light; Step (5), the printing screen (2) moves downward by 5 mm and then upward by 4.9 mm; Step (6), printing the second layer, the printing screen assembly (3) begins to cure the second layer by ultraviolet light; Step (7), repeat steps (5) and (6) until printing is completed; Step (8), printing is finished, the printing screen assembly (3) first rises and collides with the limit switch (71) to return to zero, then the printing screen (2) rises and collides with the limit switch (71) to return to zero, and then the printed model on the printing screen (2) is removed.

10. A sinking type 3D printing method, comprising the 3D printer according to any one of claims 2 to 8, characterized in that: The steps include: Step (1), firstly, the machine is reset to zero by one key, the printing screen assembly (3) first rises and collides with the limit switch (71) to return to zero, and then the printing screen plate (2) rises and collides with the limit switch (71) to return to zero; Step (2), adding the resin material into the material tank (1); Step (3), the printing screen (2) is lowered to below the liquid level in the material tank (1), and the distance between the upper side of the printing screen (2) and the liquid level is 1-5 mm, which is the 0th layer position at the beginning of printing. Subsequently, the printing screen assembly (3) is lowered to a position where the distance from the upper side of the printing screen (2) is 0.1-0.3 mm; Step (4), printing the first layer, the printing screen assembly (3) begins to cure the first layer by ultraviolet light; Step (5), the print screen assembly (3) moves upward by 5 mm, and the print screen (2) moves downward by 0.1 mm; Step (6), the printing screen assembly (3) moves downward by 5 mm; Step (7), printing the second layer, the printing screen assembly (3) begins to cure the second layer by ultraviolet light; Step (8), repeat step (5), step (6), and step (7) until printing is completed; Step (9), printing is finished, the printing screen assembly (3) first rises and collides with the limit switch (71) to return to zero, then the printing screen (2) rises and collides with the limit switch (71) to return to zero, and then the printed model on the printing screen (2) is removed.

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