A general-purpose 3D printer and its printing method

Abstract

A universal 3D printer includes a printer body and a control system. The printer body includes a lower mold and an upper mold with a flat cavity that cooperate with each other. The lower mold includes a base and several transmission components, which are spaced apart. Each transmission component includes a coaxially arranged moving rod and a transmission element. Each transmission element is rotatably or fixedly mounted on the base. Each moving rod moves up and down through the transmission element. The upper end of each moving rod is connected to a top head, and all top heads together form a working area. The control system includes a printing execution module, and the control terminals of each transmission element are electrically connected to the signal output terminal of the printing execution module. This invention can prefabricate foamed packaging based on a 3D model without relying on a physical object, effectively solving the problem of not being able to prefabricate packaging during the product design and development stage, and significantly shortening the cycle from product design to mass production of packaging. This invention also provides a printing method for a universal 3D printer.

Description

Technical Field

[0001] This invention relates to the technical field of foam material molding, and more specifically to a universal 3D printer and its printing method. Background Technology

[0002] Currently, foam packaging is generally done manually. The specific operation process is as follows: a first release film is laid at the bottom of the packaging box, and then the object to be packaged is placed face up on the first release film. Then, a second release film is placed on top of the object, and a foaming agent is added to the second release film. The second release film completely covers the object and is pressed down to make the second release film tightly press against the face of the object. After the foaming agent foams, a foam packaging half is obtained. This foam packaging half has a cavity with the shape of the front of the object. Then, a foam packaging half with a cavity with the shape of the back of the object can be obtained in the same way. The two foam packaging half are joined together to form a foam packaging box, which can be used to place the object and prevent damage to the object.

[0003] However, the foamed packaging boxes obtained by the above operation method need to have been manufactured in the physical form. If the physical form has not yet been produced or is in the design and development stage, it is impossible to prefabricate the foamed packaging, which leads to a longer cycle from product design to mass production. In addition, manual operation is cumbersome, time-consuming and labor-intensive, with low production efficiency, and it is difficult to meet the needs of large-scale production.

[0004] In view of this, this application has conducted in-depth research on this basis, resulting in this case. Summary of the Invention

[0005] The purpose of this invention is to provide a universal 3D printer and its printing method, which can directly and rapidly mold foam packaging based on the digital model of the product without relying on the physical object, effectively shortening the production cycle and improving production efficiency.

[0006] To achieve the above objectives, the solution of the present invention is:

[0007] A printing method for a universal 3D printer is disclosed. The universal 3D printer includes a printer body and a control system. The printer body includes a lower mold and an upper mold with a flat cavity. The lower mold includes a base and several vertically arranged transmission components. Each transmission component is spaced apart and includes a coaxially arranged moving rod and a transmission element. Each transmission element is rotatably or fixedly mounted on the base. Each moving rod moves vertically via the transmission element, and the upper end of each moving rod is connected to a top head. All top heads together form a working area. The control system includes a printing execution module, and the control terminals of each transmission component are electrically connected to the signal output terminal of the printing execution module.

[0008] Print by following these steps:

[0009] Step 1, Wrapping Processing: Wrapping the 3D model of the object to be packaged. The wrapping process includes simplification of precision and gap filling. The 3D model is simplified by reducing its details. Holes and / or gaps on the surface of the 3D model that are smaller than the preset value are filled.

[0010] Step 2: Placement angle selection. The 3D model processed in Step 1 is cross-sectionally selected, and the face with the most load-bearing points is selected as the downward-facing load-bearing face. Then, the placement angle of the object to be packaged is determined based on the load-bearing face to form the optimal posture of the 3D model.

[0011] Step 3: Obtain 3D packaging material. Obtain the bounding box data of the optimal pose of the 3D model and process it with the optimal pose data of the 3D model to obtain the required 3D data of the packaging material, thereby generating the preset 3D packaging material.

[0012] Step 4: Obtain the sectional 3D packaging material. According to the section selected in Step 2, the preset 3D packaging material is sectionalized to obtain two sectional 3D packaging materials. Then, the two sectional 3D packaging materials are further subdivided.

[0013] Step 5: The two 3D split packaging materials after fine subdivision processing are transferred to the printing execution module. The printing execution module controls each of the transmission components to complete the split printing of the packaging materials according to the preset trajectory, and finally obtains two split packaging materials that are adapted to the object to be packaged. After combination, a stable packaging box for the object to be packaged can be realized.

[0014] In step 2, an automatic identification method is used to obtain the face with the most load-bearing points in the 3D model. The steps of the automatic identification method are as follows:

[0015] Step A2-1: Generate the normal vectors and areas of all surfaces of the 3D model, and calculate the area score using the area scoring formula: In the formula, This is the area index. = ; This represents the contact area between the 3D model and the selected surface. The minimum area required to maintain basic stability; This is the critical stable value. This is the ideal stable value;

[0016] Step A2-2: Calculate the torque score using the torque scoring formula, which is as follows: In the formula, The torque ratio, The torque required to maintain system equilibrium The torque that causes system instability; K m,min This is the critical stable value. This is the ideal stable value;

[0017] Step A2-3: Perform contact stability scoring on all surfaces of the 3D model. The contact stability score is obtained using the following formula: S=α*S m +(1-α)*S a In the formula, α This is the torque weight, and 0 < α <1; Then, select the surface with the highest contact stability score as the load-bearing surface that needs to be arranged downwards.

[0018] In step 2, the placement angle of the 3D model is determined by an automatic placement angle method. The automatic placement angle method is to rotate the 3D model so that the surface normal vector of the load-bearing surface selected in step A2-3 is aligned with the z-axis.

[0019] The placement angle of the 3D model is optimized in two stages. The optimization process is as follows: taking the position of the 3D model determined by the automatic placement angle method as the initial placement position, based on the initial placement position, traversing the rotation combinations of 0°, 90°, 180° and 270° in the x, y and z axis directions, and calculating the envelope volume of each rotation combination. The rotation combination with the smallest envelope volume is selected as the optimal posture of the 3D model.

[0020] In step 4, if one of the two split 3D packaging materials has a packaging material size larger than the working size of the working area, the split 3D packaging material is bisected along the axis direction perpendicular to the excess size, so that the split 3D packaging material is split again to obtain two 3D subdivided split packaging materials.

[0021] Specifically, when the size of the split 3D packaging material exceeds the working size of the working area along the x-axis, the split 3D packaging material is split along a direction perpendicular to the y-axis.

[0022] When the size of the split 3D packaging material exceeds the working size of the working area along the y-axis, the split 3D packaging material is split along the x-axis.

[0023] When the dimensions of the split 3D packaging material exceed the working dimensions of the working area along the z-axis, the split 3D packaging material is split along the horizontal plane formed by the x-axis and y-axis.

[0024] After step 4, the coordinates of the 3D split material on the x and y axes are mapped one-to-one with the x and y coordinates of the corresponding mandrels. Then, the values ​​of the 3D split material in the n z-axis directions arranged in a matrix of x and y are obtained, and the height difference between each value and the height of the 3D split material is obtained. The printing execution module then converts the height differences in the matrix of x and y into electrical signals and sends them to the control terminals of each transmission component. As a result, each mandrel moves to the target position to form a curved surface that matches the cavity of the 3D split material. At the same time, the control system controls the upper mold to move downward, pressing the isolation film laid in the working area and the foam material covering the isolation film together to complete the printing of the 3D split material.

[0025] After adopting the above solution, the present invention has the following beneficial effects: The present invention completes the packaging material data processing by steps such as wrapping, placement angle selection, and 3D material splitting. Then, based on the data of the 3D packaging material splitting, the printing execution module controls the movement of the transmission components to cooperate with the upper mold to achieve layered printing and forming of the packaging material. Compared with the traditional manual foam packaging method, the present invention can prefabricate foam packaging based on 3D models without relying on physical objects, effectively solving the problem of not being able to prefabricate packaging during the product design and development stage, and significantly shortening the cycle from product design to mass production of packaging. At the same time, the automated printing process replaces cumbersome manual operation, reduces manpower input, significantly improves production efficiency, and can better meet the needs of large-scale production.

[0026] Furthermore, in the placement angle selection step, the surface with the most load-bearing points is automatically identified as the load-bearing surface, and the optimal posture is selected by combining secondary optimization of rotation combination. This not only improves the stability of the packaging, but also maximizes the use of the packaging box space and reduces the amount of packaging materials used.

[0027] Furthermore, the refined subdivision of 3D packaging materials and the bi-splitting strategy when the material exceeds the working area in this invention ensure that large packaging materials can be successfully printed and formed, avoiding the problem of production failure due to equipment working size limitations. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the printer body in the universal 3D printer of the present invention (top mold omitted).

[0029] Figure 2 This is a schematic diagram of the transmission component in the universal 3D printer of the present invention.

[0030] Figure 3 This is a schematic diagram of the 3D model in the printing method of the universal 3D printer of the present invention.

[0031] Figure 4This is a schematic diagram of the 3D model after the wrapping process in the printing method of the universal 3D printer of this invention.

[0032] Figure 5 This is a schematic diagram of the cross-sectional selection in the printing method of the universal 3D printer of the present invention.

[0033] Figure 6 This is a schematic diagram of obtaining a preset 3D packaging material in the printing method of the universal 3D printer of the present invention.

[0034] Figure 7 This is a schematic diagram of the pre-cut 3D packaging material in the printing method of the universal 3D printer of the present invention.

[0035] In the picture:

[0036] 1-Lower mold; 2-Base; 21-Base plate; 22-Upper plate; 23-Column; 3-Transmission component; 4-Moving rod; 5-Top head. Detailed Implementation

[0037] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0038] A general-purpose 3D printer suitable for printing on conventional foam packaging materials.

[0039] like Figure 1 As shown - Figure 2 As shown, the general-purpose 3D printer includes a printer body and a control system. For ease of description, the orientation of the printer body during normal use is taken as the reference direction of this invention. The printer body includes a lower mold 1 and an upper mold (not shown in the figure) that cooperate with each other. The upper mold (not shown in the figure) is located on the upper side of the lower mold 1, and the lower side of the upper mold has a flat cavity. Preferably, the upper mold can move up and down. Specifically, the upper mold adopts a moving device commonly used in conventional molds to move up and down through the moving device. The upper mold is mounted on a support through the moving device. The moving device can be a hydraulic cylinder device, a lead screw device, etc. The support can be an n-shaped support fixedly installed on the ground or the base of the lower mold 1 described below.

[0040] The aforementioned lower mold 1 includes a base 2 and several transmission components. Each transmission component is arranged vertically and evenly spaced. Preferably, each transmission component is arranged in a matrix. Each transmission component includes a transmission element 3 and a moving rod 4. The lower end of the transmission element 3 is rotatably or fixedly mounted on the base 2. Each moving element 4 moves vertically through the corresponding transmission element 3. Each transmission element 3 and moving rod 4 are arranged coaxially and can be connected together by conventional methods such as couplings, tight fitting, snap-fit, or threaded connection.

[0041] Furthermore, each of the moving rods 4 has a top head 5 mounted on its upper end. Each top head 5 is spherical, and together they form a working area for supporting and molding the packaging material. The shape of this working area can be dynamically adjusted by controlling the movement of different transmission components 3 to adapt to the printing requirements of different shapes of 3D packaging materials described below. Preferably, each top head 5 is rotatably mounted on the upper end of the corresponding moving rod 4. The two can be installed together using conventional methods such as clearance fit or key connection to ensure that the top head 5 can flexibly adjust its angle when pressing the packaging material with the upper mold, avoiding scratches or indentations on the surface of the packaging material.

[0042] It is worth mentioning that during the packaging material printing process, the working area is usually covered with a release film (such as a plastic film) to facilitate the separation of the packaging material from the working area. Therefore, the two adjacent top heads 5 can be spliced ​​together or fitted with gaps to facilitate the movement of each transmission component. At the same time, due to the role of the release film, the foam material is also prevented from leaking through the gaps between the top heads 5 during the molding process.

[0043] In this embodiment, the control system includes a printing execution module. The control terminals of each transmission component 3 are electrically connected to the signal output terminal of the printing execution module so that the printing execution module can control the movement of each transmission component 3, thereby driving each top head 5 to move up and down.

[0044] Furthermore, the aforementioned base 2 includes a base plate 21, an upper plate 22 located on the upper side of the base plate 21, and several columns 23 connecting the base plate 21 and the upper plate 22. Each column 23 is located at one of the four corners between the base plate 21 and the upper plate 22, and each transmission component is located within the enclosure of the base 2. In addition, the upper plate 22 can be replaced with a frame according to the actual situation.

[0045] Furthermore, each of the aforementioned transmission components 3 is moved up and down using a moving device, the specific structure of which is described below.

[0046] In the first structure, each transmission component 3 is a lead screw, meaning that the outer wall of each transmission component 3 is provided with an external thread section. The outer base 2 has several mounting holes, each mounting hole being paired with one transmission component 3. Each transmission component 3 is rotatably mounted in its corresponding mounting hole. The transmission component 3 can be mounted in the mounting hole using a key connection or conventional methods such as bearings. Each transmission component 3 is fitted with a moving rod 4. The upper plate 22 has several plate holes, each plate hole being paired with one moving rod 4. Each plate hole wall has an axially arranged sliding groove. Each movable rod 4 has an integrally connected sliding block arranged along the axial direction on its outer side wall. Each movable rod 4 slides and limits its movement with the corresponding slot on the plate hole through its respective sliding block. Each movable rod 4 has an internal thread section on its inner side wall. The internal thread section on each movable rod 4 is screwed into the external thread section on the corresponding transmission component 3. Each transmission component 3 is equipped with a drive motor. Each drive motor is fixedly installed on the lower side of the base plate 21. The output shaft of each drive motor is connected to the lower end of the transmission component 3. The two can be connected together by existing conventional methods such as couplings.

[0047] Thus, the vertical movement structure of each moving rod 4 is the same, so we will take one of the moving rods 4 as an example for explanation. When the drive motor starts, its output shaft drives the transmission component 3 to rotate. Since the moving rod 4 is in sliding limit cooperation with the upper plate 22 through the sliding block, the moving rod 4 cannot rotate synchronously with the transmission component 3. It can only move up and down along the axis under the action of the thread transmission of the transmission component 3, thereby driving the top head 5 to move up and down, so as to adjust the shape of the working area.

[0048] In the second structure, each transmission component 3 is a hydraulic cylinder. The base plate 21 has several mounting holes, and the cylinder body of each hydraulic cylinder is fixedly installed in one of these holes. The upper end of the piston rod of each transmission component 3 is integrally connected to a moving rod 4. Each moving rod 4 is located within the frame surrounding the base 2. Each transmission component 3 is connected to at least one hydraulic pump via a pipeline, and a control valve is installed on each pipeline. The signal input terminal of each control valve is electrically connected to the signal output terminal of the printing execution module, and the control terminal of each hydraulic pump is electrically connected to the signal output terminal of the printing execution module. Here, the control terminal of each transmission component 3 is the control terminal of the corresponding control valve. In this embodiment, the hydraulic pump is preferably a water pump.

[0049] Furthermore, each transmission component 3 is equipped with a check valve between itself and the control valve on it to prevent water backflow on the transmission component 3. Each transmission component 3 is also connected to a water pump through a pipeline. At least one water pump can be provided so that after the printer body finishes printing, the water on the transmission component 3 can be pumped out, so that each transmission component 3 can drive the corresponding moving rod 4 back to its original position.

[0050] In this embodiment, each transmission component 3 is hydraulically driven. Therefore, a conventional hydraulic system, including a water tank and a reversing valve, is also provided outside the base 2. This part adopts existing conventional operation, so it will not be described in detail.

[0051] Furthermore, in this embodiment, the number of water pumps can be at least one, that is, one water pump controls the operation of all transmission components 3. Alternatively, all transmission components 3 can be divided into multiple parts, with one water pump responsible for one part. Or, each transmission component 3 can be equipped with a water pump. The specific configuration of the water pumps can be set according to the actual situation, and will not be set here.

[0052] It should be noted that after each transmission component 3 drives the corresponding moving rod 4 to move up and down according to the actual situation, the backflow of water can make each jack 5 return to its position. However, sometimes there are cases where the jack 5 does not return to its position. In such cases, the corresponding jack 5 can be manually pressed down to return to its position.

[0053] Thus, the vertical movement structure of each moving rod 4 is the same, so we will take one moving rod 4 as an example for explanation. When it is necessary to control the transmission component to drive the top head 5 to move up and down, the printing execution module sends a control signal to the corresponding control valve. The control valve adjusts its opening according to the signal, and the hydraulic pump pumps hydraulic water (or oil) into the cylinder of the transmission component 3, pushing the piston rod to extend, thereby driving the moving rod 4 and the top head 5 to move upward. When it is necessary for the top head 5 to move downward, the printing execution module controls the control valve to reverse the action, the hydraulic water (or oil) in the transmission component 3 flows back, and the piston rod retracts under the action of gravity or spring force to drive the moving rod 4 to move synchronously, so as to realize the downward movement of the top head 5, so as to ensure that the shape of the working area meets the forming requirements of the 3D packaging material described below.

[0054] In this invention, each movable rod 4 can be moved up and down according to different types and specifications of foam packaging, making it highly versatile.

[0055] The aforementioned control system also includes a signal processing unit, which receives 3D model data of the object to be packaged from external input, processes the 3D model data according to a preset algorithm, generates control commands, and sends them to the printing execution module.

[0056] In actual operation, the user imports the 3D model of the object to be packaged into the control system or generates the 3D model in the 3D module of the control system. The signal processing unit first performs wrapping processing on the 3D model, such as simplifying accuracy and filling gaps, and then automatically identifies the load-bearing surface and optimizes the placement angle, and then generates data. After that, the printing execution module controls the movement of each transmission component 3 according to the processed sectional 3D packaging material data, so that the top head 5 forms a shape that matches the part of the sectional 3D packaging material used to accommodate the object to be packaged. At the same time, the control system controls the upper mold to move down, pressing the isolation film and foam material laid on the top head into shape, completing the printing of the corresponding packaging material. Repeating the above process, a complete foam packaging material can be obtained.

[0057] This invention provides a universal 3D printer and a printing method for the universal 3D printer, such as... Figure 3 As shown - Figure 6 As shown, the printing method includes the following steps:

[0058] Step 1: Create a 3D model of the object to be packaged to obtain the 3D model of the object, and then wrap the 3D model.

[0059] Specifically, such as Figure 3 As shown, the 3D modeling described above can be performed in the control system of the printer itself, which includes a 3D module. Alternatively, the model can be generated in 3D software and then imported into the control system. The choice between the two depends on the actual situation.

[0060] Furthermore, package processing includes simplifying precision and filling gaps, such as... Figure 4 As shown, in the simplification of precision, the details of the 3D model are slightly reduced to decrease the complexity of the 3D model. The details of the 3D model can be rounded corners, simplified surfaces, etc., thereby improving processing efficiency.

[0061] When the 3D model is a visual model, its accuracy error range is ±1~2mm, that is, the accuracy can be slightly reduced within the range of ±1~2mm; if the 3D model is a functional protection model, the accuracy error range is ±0.5mm, that is, the accuracy can be slightly reduced within the range of ±0.5mm; in this embodiment, the above-mentioned 3D model accuracy adjustment can be achieved by conventional operation, so it will not be described in detail.

[0062] In the gap filling process, a preset value is manually configured within the control system. This preset value is used to fill holes and / or gaps smaller than this value on the surface of the 3D model, preventing leakage during packaging material generation. Specifically, holes and / or gaps smaller than 2-3mm in the 3D model are automatically closed or bridged. This closure or bridging process can be implemented using existing conventional Boolean hole-filling algorithms or STL model repair tools.

[0063] Step 2, Choosing the placement angle: Select the cross-section of the 3D model processed in Step 1, i.e., as shown below. Figure 5 As shown, the surface with the most load-bearing points in the 3D model is taken as the downward-facing load-bearing surface, and then the placement angle of the 3D model is determined based on the load-bearing surface.

[0064] To elaborate, an automatic identification method is used to identify the face with the most load-bearing points in a 3D model. This automatic identification method includes the following steps:

[0065] Step A2-1: Obtain all surfaces of the 3D model, generate the face normals and areas of all surfaces, and calculate the area score using the area scoring formula: In the formula, This is the area index. = , This represents the contact area between the 3D model and the selected surface. The minimum area required to maintain basic stability can be determined through experiments or theoretical calculations. K a The larger the value, the more stable it is. This is the critical stability value, usually set to 1, i.e. A = The time was just right and stable; The ideal stable value is set according to the requirements.

[0066] Step A2-2: Simulate the gravitational direction and estimate the moment for each face of the 3D model. Here, the gravitational direction is the z-axis. Calculate the moment score using the moment scoring formula, which is: In the formula, The torque ratio quantifies the contribution of torque to stability, and is typically taken as... = , in, >1 indicates temporary stability; the larger the value, the more stable the stability. The torque required to maintain system equilibrium The torque that causes system instability; K m,min This is the critical stability value, usually set to 1 (critical stability when torque is balanced). This is the ideal stable value, set according to the application scenario.

[0067] Step A2-3: Perform contact stability scoring on all surfaces of the 3D model. The contact stability score is obtained using the following formula: S=α*S m +(1-α)*S a In the formula, α This is the torque weight, and 0 < α <1; Then, select the surface with the highest contact stability score as the load-bearing surface that needs to be arranged downwards.

[0068] In this embodiment, α You can choose to set it according to the actual situation, such as setting it to 0.7. For example, taking "tabletop object anti-tipping" as an example, the specific construction process is as follows:

[0069] 1. Torque parameter: Stabilizing torque M s =G*d In the formula, G For the object's weight, d The minimum distance from the center of gravity to the support edge; instability moment. M u =F*h , F It is a lateral force. h The force-bearing height; torque ratio K m = .

[0070] 2. Area parameters: Support area A Area index K a = , a Let be the side length of the object's base.

[0071] 3. Scoring function: If lateral force is the primary threat, then α =0.7, then S =0.7* S m +0.3* S a ,in, S The closer it is to 1, the better the stability.

[0072] Furthermore, the placement angle of the 3D model is determined by an automatic placement angle method, which involves rotating the 3D model so that the surface normal vector of the load-bearing surface selected in step A2-3 is aligned with the z-axis.

[0073] If the load-bearing surface selected in step A2-3 is an incomplete plane, then a polygonal plane fitting is performed on the load-bearing surface, and the surface normal (i.e., surface normal vector) of the fitted plane is aligned with the z-axis.

[0074] It should be noted that the above section selection generally involves cross-sectioning the 3D model. In this step, only the section of the 3D model is selected, but no cross-sectioning is performed.

[0075] As a preferred method, the placement angle of the 3D model is further optimized to save packaging box space. The secondary optimization process is as follows:

[0076] The initial placement position of the 3D model is determined using an automatic placement angle method. Based on this initial placement position, the model is rotated 0°, 90°, 180°, and 270° sequentially along the x, y, and z axes, resulting in a total of 64 rotation combinations. The volume of the envelope for each rotation combination is calculated, and the rotation combination with the smallest envelope volume is selected as the optimal pose of the 3D model. It should be noted that in this embodiment, the envelope size is calculated using the conventional minimum bounding box (OBB) method. Alternatively, the envelope size can also be calculated using the conventional axis-aligned bounding box (AABB) method or other conventional methods.

[0077] Furthermore, the optimal pose of a 3D model can also be selected by calculating the volume utilization rate, which is calculated as: Volume Utilization Rate = Volume of 3D Model / Volume of Bounding Box of 3D Model. The rotation combination with the highest volume utilization rate is selected as the optimal pose. The volume of the bounding box for each rotation combination is calculated using conventional methods, such as AABB (Axis-Aligned Bounding Box) volume calculation. Specifically, it involves traversing all vertices in each rotation combination, finding the minimum and maximum values ​​of the x, y, and z coordinates, and then calculating the lengths of the three sides and multiplying them to obtain the volume. Alternatively, the volume can be calculated using conventional OBB (Oriented Bounding Box) or Bounding Sphere volume calculations.

[0078] Step 3: Perform Boolean operations on the bounding box data of the optimal pose in the 3D model and the optimal pose data of the 3D model in Step 2 to obtain the required 3D packaging material data, and generate the preset 3D packaging material, as shown below. Figure 6 As shown.

[0079] In this embodiment, the Boolean operation described above is a conventional operation, so it will not be described in detail.

[0080] Step 4: Using the cross-section selected in Step 2, perform a sectional process on the preset 3D packaging material in Step 3 to obtain two sectional 3D packaging materials. These two sectional 3D packaging materials are arranged vertically. Then, the two sectional 3D packaging materials are further subdivided, as shown below. Figure 7 As shown.

[0081] It should be noted that in step 2, the selection of the cross-section generally chooses the largest flat surface in the 3D model as the dividing interface. Since this cross-section is a plane, the upper mold adopts an upper mold with a flat cavity. In this embodiment, the part that needs to be adjusted is the cavity shape of the lower mold, that is, the shape of the working area of ​​the printer body.

[0082] Furthermore, if the size of one or both of the two split 3D packaging materials is larger than the working area of ​​the printer body, and if the size of one split 3D packaging material exceeds the limit, then the split 3D packaging material is bisected along the axis perpendicular to the excess size, so that the split 3D packaging material is divided into two 3D subdivided split packaging materials; correspondingly, if the size of both split 3D packaging materials exceeds the limit, then the two split 3D packaging materials are divided in the above manner respectively.

[0083] Specifically, when the size of the 3D packaging material exceeds the working size of the working area along the x-axis, the 3D packaging material will be split along a direction perpendicular to the y-axis.

[0084] When the size of the split 3D packaging material exceeds the working size of the working area along the y-axis, the split 3D packaging material is split along the x-axis.

[0085] When the dimensions of the split 3D packaging material exceed the working dimensions of the working area along the z-axis, the split 3D packaging material is split along the horizontal plane formed by the x-axis and y-axis.

[0086] It is worth mentioning that the above steps can be generated in the corresponding software, that is, each 3D subdivision of the packaging material can generate a separate 3D file of the packaging material, which can then be imported into the control system for printing. In addition, the above steps can also be generated in the control system.

[0087] Among them, each pair of adjacent 3D subdivided packaging materials can also be provided with alignment slots or edge chamfers to facilitate subsequent splicing. In addition, the size of the packaging box is obtained by cutting according to the size of the packaging materials, and the packaging materials that are close to each other can be arranged close together when placed in the packaging box.

[0088] It should be noted that the above subdivision method can be combined with conventional automatic partitioning algorithms, such as Voxelization or KD-Tree space partitioning, to optimize the generation path.

[0089] Furthermore, the fine-grained subdivision processing in this embodiment is the existing conventional fine-grained subdivision processing method.

[0090] Step 5: The two 3D packaging materials after fine subdivision are transferred to the printing execution module. The printing execution module works twice according to the corresponding 3D packaging materials. When printing each 3D packaging material, the printing execution module controls the control end of each transmission component to complete the layered printing of the packaging material according to the preset trajectory. Finally, two 3D packaging materials that fit the object to be packaged are obtained. After combination, a stable packaging box for the object to be packaged can be achieved.

[0091] Specifically, in the printer body, each top head 5 is provided with three-dimensional coordinates, namely x, y, and z axis coordinates. In the initial state, the working area formed by all top heads 5 is a horizontal plane.

[0092] The printing process for the two sectional 3D packaging materials is the same, so we will use one of the sectional 3D packaging materials as an example for explanation. For ease of description, we will refer to this sectional 3D packaging material as the first sectional 3D packaging material and the other as the second sectional 3D packaging material.

[0093] During the printing process, the coordinates of the first pair of 3D packaging materials on the x and y axes are mapped one by one to the x and y axis coordinates of the corresponding top head 5. Then, the values ​​of the first pair of 3D packaging materials in the n z-axis directions arranged in a matrix of x and y are obtained, and the height difference between the n values ​​and the height of the first pair of 3D packaging materials is obtained. The height difference is the height value that the corresponding top head 5 needs to extend. Here, n refers to the number of top heads 5 that need to perform the action according to the first pair of 3D packaging materials, and the height refers to the value between the bottom surface and the cross-section of the packaging material.

[0094] Then, the printing execution module converts the height differences of the first pair of 3D packaging materials arranged in an x ​​and y matrix into electrical signals and sends them to the control terminals of each transmission component 3, thereby enabling each mandrel 5 to move precisely to the target position and form a curved surface that matches the cavity of the first pair of 3D packaging materials. Subsequently, the control system controls the upper mold to move down, pressing the isolation membrane laid in the working area and the foam material covered in the isolation membrane together. The expansion characteristics of the foam material are used to fill the cavity space. After the material is cured and formed, the upper mold is reset and the mandrel 5 returns to its original position to complete the printing of the first pair of 3D packaging materials.

[0095] In this embodiment, the printing process of the second split 3D packaging material is the same as that of the first split 3D packaging material. Only the extension height of each top head 5 needs to be adjusted according to its corresponding cavity data. Through this synergistic effect of layered printing and height control, it is ensured that the two split packaging materials that are finally formed can be seamlessly spliced ​​together, providing a close-fitting buffer protection structure for the object to be packaged.

[0096] The present invention discloses a printing method that employs steps such as wrapping a 3D model, optimizing the placement angle, generating packaging material data through Boolean operations, slitting and fine subdivision, and combining a flexible driving method of a transmission component to achieve efficient molding of packaging materials of different specifications. It is highly versatile and does not rely on physical objects, which can effectively shorten the production cycle and improve production efficiency.

[0097] The above description is only a preferred embodiment of this invention. Any equivalent changes and modifications made within the scope of the claims of this invention shall fall within the scope of the claims of this invention.

Claims

1. A printing method for a universal 3D printer, characterized in that, This invention relates to a general-purpose 3D printer, which includes a printer body and a control system. The printer body includes a lower mold and an upper mold with a flat cavity. The lower mold includes a base and several vertically arranged transmission components. Each transmission component is spaced apart and includes a coaxially arranged moving rod and a transmission element. Each transmission element is rotatably or fixedly mounted on the base. Each moving rod moves vertically via the transmission element, and the upper end of each moving rod is connected to a top head. The top heads together form a working area. The control system includes a printing execution module, and the control terminals of each transmission component are electrically connected to the signal output terminal of the printing execution module. Print by following these steps: Step 1, Wrapping Processing: Wrapping the 3D model of the object to be packaged. The wrapping process includes simplification of precision and gap filling. The 3D model is simplified by reducing its details. Holes and / or gaps on the surface of the 3D model that are smaller than the preset value are filled. Step 2: Placement angle selection. The 3D model processed in Step 1 is cross-sectionally selected, and the face with the most load-bearing points is selected as the downward-facing load-bearing face. Then, the placement angle of the object to be packaged is determined based on the load-bearing face to form the optimal posture of the 3D model. Step 3: Obtain 3D packaging material. Obtain the bounding box data of the optimal pose of the 3D model and process it with the optimal pose data of the 3D model to obtain the required 3D data of the packaging material, thereby generating the preset 3D packaging material. Step 4: Obtain the sectional 3D packaging material. According to the section selected in Step 2, the preset 3D packaging material is sectionalized to obtain two sectional 3D packaging materials. Then, the two sectional 3D packaging materials are further subdivided. Step 5: The two 3D split packaging materials after fine subdivision processing are transferred to the printing execution module. The printing execution module controls each of the transmission components to complete the split printing of the packaging materials according to the preset trajectory, and finally obtains two split packaging materials that are adapted to the object to be packaged. After combination, a stable packaging box for the object to be packaged can be realized.

2. The printing method of a universal 3D printer according to claim 1, characterized in that: In step 2, an automatic identification method is used to obtain the face with the most load-bearing points in the 3D model. The steps of the automatic identification method are as follows: Step A2-1: Generate the normal vectors and areas of all surfaces of the 3D model, and calculate the area score using the area scoring formula: In the formula, This is the area index. = ; This represents the contact area between the 3D model and the selected surface. The minimum area required to maintain basic stability; This is the critical stable value. This is the ideal stable value; Step A2-2: Calculate the torque score using the torque scoring formula, which is as follows: In the formula, The torque ratio, The torque required to maintain system equilibrium The torque that causes system instability; K m,min This is the critical stable value. This is the ideal stable value; Step A2-3: Perform contact stability scoring on all surfaces of the 3D model. The contact stability score is obtained using the following formula: S=α*S m +(1-α)*S a In the formula, α This is the torque weight, and 0 < α <1; Then, the surface with the highest contact stability score is selected as the load-bearing surface that needs to be placed downwards.

3. The printing method of a universal 3D printer according to claim 2, characterized in that: In step 2, the placement angle of the 3D model is determined by an automatic placement angle method. The automatic placement angle method is to rotate the 3D model so that the surface normal vector of the load-bearing surface selected in step A2-3 is aligned with the z-axis.

4. The printing method of a universal 3D printer according to claim 3, characterized in that: The placement angle of the 3D model is optimized in two stages. The optimization process is as follows: taking the position of the 3D model determined by the automatic placement angle method as the initial placement position, based on the initial placement position, traversing the rotation combinations of 0°, 90°, 180° and 270° in the x, y and z axis directions, and calculating the envelope volume of each rotation combination. The rotation combination with the smallest envelope volume is selected as the optimal posture of the 3D model.

5. The printing method of a universal 3D printer according to claim 1, characterized in that: In step 4, if one of the two split 3D packaging materials has a packaging material size larger than the working size of the working area, the split 3D packaging material is bisected along the axis direction perpendicular to the excess size, so that the split 3D packaging material is split again to obtain two 3D subdivided split packaging materials. Specifically, when the size of the split 3D packaging material exceeds the working size of the working area along the x-axis, the split 3D packaging material is split along a direction perpendicular to the y-axis. When the size of the split 3D packaging material exceeds the working size of the working area along the y-axis, the split 3D packaging material is split along the x-axis. When the dimensions of the split 3D packaging material exceed the working dimensions of the working area along the z-axis, the split 3D packaging material is split along the horizontal plane formed by the x-axis and y-axis.

6. The printing method of a universal 3D printer according to claim 5, characterized in that: After step 4, the coordinates of the 3D split material on the x and y axes are mapped one-to-one with the x and y coordinates of the corresponding mandrels. Then, the values ​​of the 3D split material in the n z-axis directions arranged in a matrix of x and y are obtained, and the height difference between each value and the height of the 3D split material is obtained. The printing execution module then converts the height differences in the matrix of x and y into electrical signals and sends them to the control terminals of each transmission component. As a result, each mandrel moves to the target position to form a curved surface that matches the cavity of the 3D split material. At the same time, the control system controls the upper mold to move downward, pressing the isolation film laid in the working area and the foam material covering the isolation film together to complete the printing of the 3D split material.

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