Strong constraint forming 3D printing method and 3D printing device

Abstract

The invention discloses a 3D printing method and a 3D printing device for strong constraint forming, and relates to the field of 3D printing, and a prepared product has an interlayer mortise and tenon joint structure. The front end of the printing opening is provided with a restraining blocking piece, the rear end of the printing opening is provided with a tenon-and-mortise blocking piece capable of rotating and switching, and the two sides of the printing opening are provided with contour restraining pieces for adjusting the extending length to form a restraining space. And the forming material is filled and formed in the constraint space, a negative draft angle groove mortise structure is formed after the forming material is extruded from the mortise and tenon separation blade, and in the layer-by-layer printing process, the groove mortise structure is filled with the forming material, and then an interlayer mortise and tenon structure is formed. A laser heater is installed at the front end of the printing head to preheat a printing path, and a roller is installed at the rear end of the printing head to compact a printed lamellar structure. The method has the advantages that shell constraint forming is carried out on the product contour curved surface, interlayer combination is changed into mortise and tenon joint from traditional adhesion combination, interlayer combination is tighter, the product appearance is good, the forming efficiency is high, and the product performance is better guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing, and relates to a 3D printing method and a 3D printing device with strong constraint forming. Background Art

[0002] In recent years, 3D printing technology has developed rapidly. It has lowered the threshold for product manufacturing, made the production method more flexible and convenient, and significantly reduced material waste compared to traditional manufacturing methods. It can produce complex shapes and structures that are difficult or impossible to produce with traditional manufacturing methods, and can also customize products according to personal needs. These characteristics have made it widely used in the fields of construction, education, mechanical manufacturing, aerospace, medical and bioengineering.

[0003] At present, 3D printing generally adopts the manufacturing process of "layered slicing and layer-by-layer accumulation". Usually, the entire forming area needs to be printed, and the suspended parts of the product need to be equipped with additional support parts, which not only reduces the processing efficiency, but also produces a step effect on the surface of the workpiece. In addition, the weak interlayer bonding force caused by the traditional adhesion bonding method affects the mechanical properties of the product and limits the market competitiveness of 3D printing technology. In order to effectively improve the competitiveness of 3D printing technology and products, improving the forming efficiency, forming accuracy, and enhancing the interlayer bonding strength to ensure product performance during the preparation process are key issues that need to be urgently addressed in 3D printing technology. Summary of the invention

[0004] In view of the above problems, the present invention proposes a 3D printing method and a 3D printing device with strong constraint forming, and the product prepared by the method has an interlayer mortise and tenon structure.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a 3D printing method, comprising the following steps:

[0007] Step 1: Model processing: draw the target print part contour model and process it to obtain the trajectory of each layer contour, the length of the control piece, and the mortise and tenon structure information;

[0008] Step 2: Prepare the printing equipment. The 3D printing equipment has a multi-axis motion mechanism, which can flexibly and accurately adjust the position and angle of the print head and the length of the contour control piece. A contour control piece is set on the side of the print port, and a constraint baffle is provided at the front end of the print port in the direction of movement, and a rotatable mortise and tenon baffle is provided at the rear end. The print head is moved to the corresponding position and angle through the multi-axis motion mechanism, the extension length of the contour control piece is adjusted, and the size structure of the mortise and tenon baffle is rotated and switched;

[0009] Step 3: Print the first layer of the mortise and tenon structure. The forming material is extruded from the print head and enters the constraint space surrounded by the contour control sheet, the constraint baffle, the mortise and tenon baffle and the base. The constraint space is filled under the extrusion pressure. The laser heater is turned on. As the print head moves, the track to be printed is preheated in advance. The print head moves forward. The forming material extruded from the constraint space passes through the mortise and tenon baffle to form a sheet structure with a groove mortise with a negative draft angle. The roller compacts the newly formed sheet structure.

[0010] Step 4: Multi-layer printing of the mortise and tenon structure. When one layer of structure is printed, the print head is moved to the corresponding position of the next layer and printing is continued. The laser heater is turned on to preheat the track to be printed in advance. The extruded forming material fills the constraint space and fills the groove mortise structure of the lower layer to form the mortise and tenon structure. The roller compacts the newly formed sheet structure.

[0011] Step 5: Printing process detection and adjustment: the camera detects the extrusion state of the forming material and the forming quality of the layer structure, and the control system adjusts the extrusion speed according to the monitoring results.

[0012] Preferably, during the printing process, as needed, the extension length of the contour control plates on both sides of the print head is adjusted to change the printing layer height, the mortise and tenon baffles are rotated and switched, and a suitable baffle is selected to prepare a groove mortise structure with a negative draft angle.

[0013] Preferably, the camera monitors the extrusion state of the molding material and the forming quality of the sheet structure during the printing process and provides feedback.

[0014] Preferably, the laser heater preheats the printing track, and the roller squeezes to make the layers more closely bonded.

[0015] The present invention also provides a 3D printing device suitable for the 3D printing method, comprising a six-axis robotic arm, a frame, a camera, an extrusion mechanism, and a print head main body structure, wherein the frame is installed at the end of the six-axis robotic arm, the camera is installed under the frame, and the print head main body structure is installed at the frame slot.

[0016] Preferably, the extrusion mechanism comprises a connecting hose and an extruder, the extruder is mounted on the side of the frame, and the connecting hose connects the extruder and the main body of the print head.

[0017] Preferably, the main structure of the print head includes a hose connector, a radiator, a throat, a print head, a roller, a laser heater, a bearing seat, a spring, a stepper motor for contour control sheet A, contour control sheet A, a stepper motor for contour control sheet B, contour control sheet B, a mortise and tenon baffle, a stepper motor for mortise and tenon baffle, a constraint baffle, and a stepper motor for a constraint baffle; the contour control sheet A, contour control sheet B, and constraint baffle are respectively connected to the stepper motor with a lead screw, the mortise and tenon baffle is connected to the stepper motor with a gear, the laser heater is installed on the front side of the print head in the direction of movement, and the roller is installed on the rear side of the print head in the direction of movement with a spring connection.

[0018] The working principle of the 3D printing head device is as follows: the molding material is inserted into the extruder, the rotation speed and printing temperature of the extruder are set and adjusted according to actual needs, the molding material is extruded from the extruder and enters the printing head through the connecting hose, and enters the closed space surrounded by the contour control sheet, the constraint baffle, the mortise and tenon baffle, and the lower structure, and the constraint space is filled under the action of the extrusion pressure; the laser heater is turned on to preheat the printing track, the printing head moves forward, and the molding material forms a sheet structure with grooves when passing through the mortise and tenon baffle, and the roller compacts the newly formed sheet structure with grooves. When the printing of one layer of structure is completed, the print head is moved to the corresponding position of the next layer and the printing is continued. The laser heater is turned on to preheat the track to be printed in advance, and then the newly extruded molding material fills the groove structure of the lower layer to form a mortise and tenon structure, and the roller compacts the extruded sheet structure. During the printing process, the camera monitors the extrusion state of the molding material and the forming quality of the sheet structure, and makes corresponding adjustments according to the monitoring situation. The six-axis robotic arm can realize all-round and multi-angle printing. Furthermore, the printing slot is adjusted by replacing the mortise and tenon baffle slot with a stepper motor, the extension length of contour control sheet A is adjusted by a stepper motor, and the extension length of contour control sheet B is adjusted by a stepper motor, thereby adjusting the layer height of the formed shell.

[0019] The effects and benefits of the present invention are:

[0020] (1) The material is formed under strong constraint conditions, and the interlayer bonding method is mortise and tenon joints. The combination of laser heater and roller makes the interlayer bonding strength higher than that of traditional adhesive bonding.

[0021] (2) The camera monitors the extrusion of the molding material during the printing process and makes corresponding adjustments based on the extrusion conditions.

[0022] (3) The forming speed is fast and the precision is high. The cross-section of the formed contour can be regarded as connected by broken line segments, which effectively avoids the step effect and improves the surface precision and forming efficiency of the curved surface.

[0023] (4) During the forming process, the length of the contour control sheet and the size structure of the rotationally switched mortise and tenon baffle can be adjusted by a stepper motor, thereby improving the freedom and flexibility of the print head.

[0024] (5) Based on the six-axis robotic arm motion mechanism, all-round and multi-angle printing can be achieved, and the printing position is not restricted, which improves the flexibility of printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A diagram of a print head device according to the present invention.

[0026] Figure 2 It is an overall diagram of the present invention.

[0027] Figure 3 This is a diagram of the rotatable switching mortise and tenon stopper of the present invention.

[0028] Figure 4 3D diagram and cross-sectional diagram of the product of the embodiment of the present invention.

[0029] In the figure, 1 is a spring; 2 is a bearing seat; 3 is a stepper motor for a mortise and tenon baffle; 4 is a roller; 5 is a mortise and tenon baffle; 6 is a contour constraint sheet A; 7 is a constraint baffle; 8 is a laser heater; 9 is a print head; 10 is a throat; 11 is a heat sink; 12 is a hose interface; 13 is a stepper motor for a constraint baffle; 14 is a stepper motor for a contour constraint sheet B; 15 is a stepper motor for a contour constraint sheet A; 16 is an interlayer mortise and tenon structure; 17 is an extruder; 18 is a connecting hose; 19 is a frame; 20 is a camera; 21 is a robotic arm. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings. The present invention includes but is not limited to the following embodiments.

[0031] Step 1: Draw the contour model of the target formed part and process it to obtain the trajectory of each layer of contour, control the length of the slice, set the printing temperature and material extrusion speed, the contour shell width is 3mm, the odd layer height is 2mm, and the even layer height is 4mm;

[0032] Step 2: In this example, a Lebai LM3 six-axis robot is used as the motion mechanism. The printing device is installed at the end of the robot. The extension length of the contour control sheet is adjusted to 2 mm. The mortise and tenon baffle is adjusted to select a baffle with a mortise height of 0.5 mm, a bottom width of 1 mm, and a draft angle of -3°. The control program is edited based on the Python programming language to regulate the movement of the robot and move the print head to the initial printing position.

[0033] Step 3: The forming material is PLA, and the heating temperature is 200°C. The extruder drives the PLA filament to extrude the molten forming material from the print head and enter the closed space surrounded by the contour control sheet, the constraint baffle, the mortise and tenon baffle, and the substrate. The constraint space is filled under the extrusion pressure. The laser heater is turned on, and the print head moves forward. The laser heater preheats the forming track. The preheating temperature is 100°C. When the forming material is extruded from the mortise and tenon baffle, a sheet structure with a groove and a mortise with a negative draft angle is formed. The roller compacts the newly formed sheet structure with a groove.

[0034] Step 4: When one layer of structure is printed, move the print head to the corresponding position of the next layer and continue printing. If it is an even number of layers, adjust the extended length of the contour control sheet to 4mm, select the mortise and tenon baffle with a mortise height of 1mm, a bottom width of 1.5mm, and a draft angle of -2°. If it is an odd number of layers, the parameters of the contour control sheet and the mortise and tenon baffle are the same as those in step 3. Turn on the laser heater, preheat the track to be printed in advance, and the preheating temperature is 100°C. The extruded forming material fills the constraint space and fills the groove structure of the lower layer to form an interlayer mortise and tenon structure. The roller compacts the newly extruded sheet structure.

[0035] Step 5: During the shell forming process, when the camera detects that the extruded material is uneven, the printing speed is adjusted. If the extrusion is insufficient and the constraint space is not filled, the extrusion speed is increased; if the extrusion overflows, the extrusion speed is reduced;

[0036] The above process is repeated until the 3D printing of the entire molded part is completed.

Claims

1. A 3D printing method, characterized in that: The following steps are involved: Step 1: Model processing: draw the target print part contour model and process it to obtain the trajectory of each layer contour, the length of the control piece, and the mortise and tenon structure information; Step 2: Prepare the printing equipment. The 3D printing equipment has a multi-axis motion mechanism, which can flexibly and accurately adjust the position and angle of the print head and the length of the contour control piece. A contour control piece is set on the side of the print port, and a constraint baffle is provided at the front end of the print port in the direction of movement, and a rotatable mortise and tenon baffle is provided at the rear end. The print head is moved to the corresponding position and angle through the multi-axis motion mechanism, the extension length of the contour control piece is adjusted, and the size structure of the mortise and tenon baffle is rotated and switched; Step 3: Print the first layer of the mortise and tenon structure. The forming material is extruded from the print head and enters the constraint space surrounded by the contour control sheet, the constraint baffle, the mortise and tenon baffle and the base. The constraint space is filled under the extrusion pressure. The laser heater is turned on. As the print head moves, the track to be printed is preheated in advance. The print head moves forward. The forming material extruded from the constraint space passes through the mortise and tenon baffle to form a sheet structure with a groove mortise with a negative draft angle. The roller compacts the newly formed sheet structure. Step 4: Multi-layer printing of the mortise and tenon structure. When one layer of structure is printed, the print head is moved to the corresponding position of the next layer and printing is continued. The laser heater is turned on to preheat the track to be printed in advance. The extruded forming material fills the constraint space and fills the groove mortise structure of the lower layer to form the mortise and tenon structure. The roller compacts the newly formed sheet structure. Step 5: Printing process detection and adjustment: the camera detects the extrusion state of the forming material and the forming quality of the sheet structure, and the control system adjusts the extrusion speed according to the monitoring results.

2. The 3D printing method according to claim 1, characterized in that: The forming material is formed within the confined space.

3. The 3D printing method according to claim 1, characterized in that: During the printing process, the extended length of the contour control piece can be adjusted as needed to change the printing layer height, and the mortise and tenon stopper can be rotated to change the size structure of the groove mortise.

4. The 3D printing method according to claim 1, characterized in that: Adjacent layers are connected by mortise and tenon structures, and the mortise and tenon structures have a negative draft angle.

5. The 3D printing method according to claim 1, characterized in that: Laser heater preheating and roller extrusion make the layers more closely bonded.

6. A 3D printing device applicable to the 3D printing method according to any one of claims 1 to 5, characterized in that: It includes a six-axis mechanical arm, a frame, a camera, an extrusion mechanism, and a print head main structure. The frame is installed at the end of the six-axis mechanical arm, the camera is installed under the frame, and the print head main structure is installed at the frame slot.

7. The 3D printing device according to claim 6, characterized in that: The main structure of the print head includes a hose joint, a radiator, a throat, a print head, a roller, a laser heater, a bearing seat, a spring, a stepper motor for contour control sheet A, contour control sheet A, a stepper motor for contour control sheet B, contour control sheet B, a mortise and tenon baffle, a stepper motor for mortise and tenon baffle, a constraint baffle, and a stepper motor for a constraint baffle; the contour control sheet A, contour control sheet B, and constraint baffle are respectively connected to the stepper motor with a lead screw, the mortise and tenon baffle is connected to the stepper motor with a gear, the laser heater is installed on the front side of the print head in the direction of movement, and the roller is installed on the rear side of the print head in the direction of movement with a spring connection.

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