A 3D printing method and 3D printing device for strong constraint forming

Abstract

The application discloses a kind of 3D printing method and 3D printing device of strong constraint forming, it is related to 3D printing field, and the product prepared has interlayer mortise and tenon structure.Printing mouth front end installs constraint baffle, printing mouth rear end installs the mortise and tenon baffle of rotation switching, the profile constraint piece of adjusting protruding length is installed in the both sides of printing mouth, and constraint space is formed.Forming material is filled and formed in constraint space, and after extrusion from mortise and tenon baffle, it forms negative draft angle groove mortise eye structure, and in the process of layer-by-layer printing, interlayer mortise and tenon structure is formed after forming material fills groove mortise eye structure.In the front end of printing head, laser heater is installed to preheat printing path, and roller is installed in the rear end of printing head to compact sheet structure after printing.The effect and benefit of the application are as follows: product profile curved surface is constrained and formed by shell, so that interlayer combination is changed from traditional adhesion combination to mortise and tenon combination, interlayer combination is more compact, product appearance is good, forming efficiency is high, and product performance is more guaranteed.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of 3D printing, and relates to a 3D printing method and a 3D printing device for strong constraint forming. BACKGROUND

[0002] In recent years, 3D printing technology has developed rapidly, which reduces the manufacturing threshold of products, makes the production mode more flexible and convenient, can significantly reduce the waste of materials compared with traditional manufacturing methods, can manufacture complex shapes and structures that are difficult or impossible to produce by traditional manufacturing methods, and can also customize products according to individual needs. These characteristics make it widely used in fields such as architecture, education, mechanical manufacturing, aerospace, medical treatment and biological engineering.

[0003] At present, 3D printing generally adopts a manufacturing process of 'layered slicing and layer-by-layer accumulation'. In general, the entire forming area needs to be printed, and the overhanging part of the product needs to be provided with an additional support part, which not only reduces the processing efficiency, but also produces a step effect on the surface of the workpiece, and the weak interlayer bonding force caused by the traditional adhesion bonding mode affects the mechanical properties of the product, limiting the market competitiveness of the 3D printing technology. In order to effectively improve the competitiveness of 3D printing technology and products, improving the forming efficiency, forming precision and enhancing the interlayer bonding strength to ensure the performance of the product during preparation is a key problem that needs to be solved for 3D printing technology. SUMMARY

[0004] In view of the above problems, the application provides a 3D printing method and a 3D printing device for strong constraint forming, and the product prepared by the method has a mortise and tenon structure.

[0005] To achieve the above object, the application provides the following scheme:

[0006] The application provides a 3D printing method, which comprises the following steps:

[0007] Step one, model processing, drawing the contour model of the target printed part, and processing the contour model to obtain the trajectory of each layer contour, the length of the control sheet, and the mortise and tenon structure information;

[0008] Step two, preparing 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 printing head, the length of the contour control sheet, the contour control sheet is arranged on the side of the printing port, the front end of the printing port movement direction is provided with a constraint baffle, and the rear end is provided with a mortise and tenon baffle which is rotatably switched, the multi-axis motion mechanism is used to move the printing head to the corresponding position and angle, adjust the extension length of the contour control sheet, and rotate and switch the size structure of the mortise and tenon baffle;

[0009] Step three, the first layer of the mortise and tenon structure is printed, the forming material is extruded from the print head into the constraint space surrounded by the profile control piece, the constraint baffle, the mortise and tenon baffle and the base, and the constraint space is filled under the extrusion pressure, the laser heater is turned on, the printing path to be printed is preheated in advance as the print head moves, the print head moves forward, and the forming material extruded from the constraint space forms a sheet structure with a negative draft angle groove mortise when passing through the mortise and tenon baffle, and the roller compacts the sheet structure just formed;

[0010] Step four, multi-layer printing of the mortise and tenon structure, after the printing of a 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, the printing path to be printed is preheated 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, and the roller compacts the sheet structure just formed;

[0011] Step five, 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 result.

[0012] Preferably, the extension length of the profile control pieces on both sides of the print head is adjusted as needed during the printing process, the printing layer height is changed, the mortise and tenon baffles are switched, and the baffles suitable for preparing the groove mortise structure with a negative draft angle are selected.

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

[0014] Preferably, the laser heater preheats the printing path, and the roller extrusion makes the interlayer combination more compact.

[0015] The application also provides a 3D printing device suitable for the 3D printing method, which comprises a six-axis mechanical arm, a rack, a camera, an extrusion mechanism and a print head main body mechanism, the rack is installed at the end of the six-axis mechanical arm, the camera is installed below the rack, and the print head main body mechanism is installed at the slot of the rack.

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

[0017] Preferably, the print head body structure comprises a hose joint, a heat sink, a throat, a print head, a roller, a laser heater, a bearing seat, a spring, a profile control piece A stepper motor, a profile control piece A, a profile control piece B stepper motor, a profile control piece B, a mortise and tenon stopper, a mortise and tenon stopper stepper motor, a constraint stopper, a constraint stopper stepper motor; the profile control piece A, the profile control piece B and the constraint stopper are respectively connected with the stepper motor through a lead screw, the mortise and tenon stopper is connected with the stepper motor through a gear, the laser heater is installed on the front side of the print head movement direction, and the roller is installed on the rear side of the print head movement direction through spring connection.

[0018] The working principle of the 3D print head device is as follows: the forming material is inserted into an extruder, the rotating speed and printing temperature of the extruder are set and adjusted according to actual needs, the forming material is extruded from the extruder and then enters the print head through a connecting hose, enters a closed space surrounded by a profile control piece, a constraint stopper, a mortise and tenon stopper and a lower structure, and fills the constraint space under the action of extrusion pressure; the laser heater is turned on to preheat the printing track, the print head moves forward, the forming material forms a lamella structure with a groove when passing through the mortise and tenon stopper, and the roller compacts the just-formed lamella structure with a groove. When a layer structure is printed, the print head is moved to the corresponding position of the next layer and continues to print, the laser heater is turned on to preheat the track to be printed in advance, then the newly extruded forming material fills the groove structure of the lower layer to form a mortise and tenon structure, and the roller compacts the extruded lamella structure. In the printing process, a camera monitors the extrusion state of the forming material and the forming quality of the lamella structure, and makes corresponding adjustments according to the monitoring situation. The six-axis mechanical arm can realize omnidirectional and multi-angle printing, further, the printing slot is adjusted by exchanging the mortise and tenon stopper slot through the mortise and tenon stopper stepper motor, the extension length of the profile control piece A is adjusted through the profile control piece A stepper motor, and the extension length of the profile control piece B is adjusted through the profile control piece B stepper motor, so as to adjust and control the layer height of the forming shell.

[0019] The effects and benefits of the present application are as follows:

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

[0021] (2) The camera monitors the extrusion state of the forming material in the printing process, and makes corresponding adjustments according to the extrusion state.

[0022] (3) The forming speed is fast and the precision is high, the cross section of the forming profile can be regarded as being connected by broken lines, the step effect is effectively avoided, and the surface precision and forming efficiency of the curved surface are improved.

[0023] (4) In the forming process, the length of the profile control piece and the size structure of the mortise and tenon blocking piece can be adjusted through the stepping motor, so that the freedom and flexibility of the printing head are improved.

[0024] (5) Based on the six-axis mechanical arm movement mechanism, omnidirectional and multi-angle printing can be realized, the printing position is not limited, and the flexibility of printing is improved. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a printing head device of the application.

[0026] Figure 2 It is a whole figure of the application.

[0027] Figure 3 It is a mortise and tenon blocking piece of the application.

[0028] Figure 4 It is a 3D figure and sectional view of the embodiment product of the application.

[0029] In the figure, 1 spring; 2 bearing seat; 3 mortise and tenon blocking piece stepping motor; 4 roller; 5 mortise and tenon blocking piece; 6 profile constraint piece A; 7 constraint blocking piece; 8 laser heater; 9 printing head; 10 throat pipe; 11 radiator; 12 hose interface; 13 constraint blocking piece stepping motor; 14 profile constraint piece B stepping motor; 15 profile constraint piece A stepping motor; 16 interlayer mortise and tenon structure; 17 extruder; 18 connecting hose; 19 rack; 20 camera; 21 mechanical arm. DETAILED DESCRIPTION

[0030] The application will be further described below in combination with the drawings, and the application includes but is not limited to the following examples.

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

[0032] Step two, in this example, a Leba LM3 six-axis mechanical arm is used as a movement mechanism, the printing device is installed at the end position of the mechanical arm, the extension length of the profile control piece is adjusted to 2mm, the mortise and tenon blocking piece is adjusted, the blocking piece with a mortise eye height of 0.5mm, a bottom width of 1mm and a draft angle of -3° is selected, a control program is edited based on Python program language, the movement of the mechanical arm is adjusted and controlled, and the printing head is moved to the initial printing position.

[0033] Step three, the forming material is PLA, the heating temperature is 200℃, the PLA filament driven by the extruder extrudes the molten forming material from the print head into the closed space surrounded by the profile control sheet, the constraint baffle, the mortise and tenon baffle and the base plate, fills the constraint space under the action of extrusion pressure, the laser heater is turned on, the print head moves forward, the laser heater preheats the forming track, the preheating temperature is 100℃, the forming material extrudes from the mortise and tenon baffle to form a sheet structure with a negative draft angle groove mortise, and the roller compacts the sheet structure with grooves just formed;

[0034] Step four, after the printing of a layer structure is completed, the print head is moved to the corresponding position of the next layer and the printing is continued, if it is an even layer, the length of the profile control sheet is adjusted to 4mm, the mortise and tenon baffle with mortise height of 1mm, bottom width of 1.5mm and draft angle of -2° is selected, if it is an odd layer, the parameters of the profile control sheet and the mortise and tenon baffle are the same as those in step three, the laser heater is turned on, the track to be printed is preheated in advance, the preheating temperature is 100℃, the extruded forming material fills the constraint space and fills the groove structure of the lower layer to form the interlayer mortise and tenon structure, and the roller compacts the sheet structure just extruded;

[0035] Step five, during the forming of the shell, the camera monitors the extruded material, if the extruded material is not uniform, the printing speed is adjusted, if the extruded material is not enough to fill the constraint space, the extrusion speed is increased, if the extruded material is overflowed, the extrusion speed is reduced;

[0036] Repeat the above process until the 3D printing of the entire formed part is completed.

Claims

1. A 3D printing method, characterized in that, Includes the following steps: Step 1: Model processing. Draw the outline model of the target printed part and process it to obtain the trajectory of each outline layer, 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 plate. The contour control plate is set on the side of the print port. There is a constraint baffle at the front end of the print port movement direction and a rotating and switching tenon baffle 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 plate is adjusted, and the size structure of the tenon baffle is rotated and switched. Step 3: First layer printing of mortise and tenon structure. The forming material is extruded from the print head and enters the constraint space surrounded by contour control plate, constraint baffle, mortise and tenon baffle and base. Under the action of extrusion pressure, the constraint space is filled. The laser heater is turned on and the printing trajectory is preheated as the print head moves. The print head moves forward. When the forming material extruded from the constraint space passes through the mortise and tenon baffle, it forms a sheet structure with grooves and mortises with negative draft angle. The roller compacts the newly formed sheet structure. Step 4: Multi-layer printing of mortise and tenon structure. After the first layer of structure is printed, the print head is moved to the corresponding position of the next layer and printing continues. The laser heater is turned on to preheat the trajectory to be printed. The extruded forming material fills the constraint space and fills the groove and 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 a constrained space.

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

4. The 3D printing method according to claim 1, characterized in that, Adjacent layers are connected by mortise and tenon joints, which 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 interlayer bonding tighter.

6. A 3D printing apparatus suitable for the 3D printing method according to any one of claims 1-5, characterized in that, It includes a six-axis robotic arm, a frame, a camera, an extrusion mechanism, and a printhead main structure. The frame is installed at the end of the six-axis robotic arm, the camera is installed under the frame, and the printhead main structure is installed at the slot of the frame.

7. The 3D printing apparatus according to claim 6, characterized in that, The main structure of the printhead includes a hose connector, a heat sink, a throat, a printhead, a roller, a laser heater, a bearing seat, a spring, a stepper motor for contour control plate A, a stepper motor for contour control plate A and contour control plate B, a contour control plate B, a tenon and mortise stop plate, a stepper motor for the tenon and mortise stop plate, a constraint stop plate, and a stepper motor for the constraint stop plate. Contour control plate A, contour control plate B, and constraint stop plate are each connected to the stepper motor by a lead screw, and the tenon and mortise stop plate is connected to the stepper motor by a gear. The laser heater is installed on the front side of the printhead's movement direction, and the roller is connected by a spring and installed on the rear side of the printhead's movement direction.

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