CN-121989457-A - 3D printing method and 3D printer

CN121989457ACN 121989457 ACN121989457 ACN 121989457ACN-121989457-A

Abstract

The disclosure provides a 3D printing method and a 3D printer. The method comprises the steps of generating an initial printing path, dividing the initial printing path into a plurality of discrete deposition sections, controlling a printing spray head to sequentially perform material deposition according to the discrete deposition sections, acquiring structural state data of a printed structure and determining corresponding geometric state parameters when a printing parameter change request is received in a printing process, determining target printing parameters based on current printing parameters and the printing parameter change request, determining structural stability parameters of a next deposition layer by combining printing material characteristic parameters and geometric state parameters, and re-planning an unexecuted printing path when the structural stability parameters meet structural stability constraint conditions, otherwise, maintaining the current printing path or generating a structural compensation deposition path to continue printing. The method and the device can judge the structural stability of the printing parameter change in the printing process, realize the dynamic adjustment of the printing path, and improve the stability of the printing structure and the printing success rate.

Inventors

Yi Xinhang
YU CHUANCHUAN
Chen Xuanle
SUN YIFAN
CHEN DONGLAI
ZHANG CHENYANG
WANG TAIYUE
CHEN GUOPENG
SUN HANQI
SUN YISHU

Assignees

北京汇科恒源激光技术有限公司
易欣航

Dates

Publication Date: 20260508
Application Date: 20260330

Claims (10)

1. A 3D printing method applied to a control system of a 3D printer, the method comprising: Generating an initial printing path according to printing request information of a target user, and dividing the initial printing path into a plurality of continuous discrete deposition segments, wherein each discrete deposition segment corresponds to a group of printing parameters; controlling the 3D printer to perform material deposition segment by segment according to the sequence of each discrete deposition segment in the initial printing path; In the process of carrying out material deposition on the current discrete deposition section, when a printing parameter change request is received, the following structure stability judging operation is carried out: acquiring structural state data of a printed structure, and determining geometric state parameters of the printed structure based on the structural state data; Determining a changed target printing parameter based on the current printing parameter and the printing parameter change request; determining a structural stability parameter of a next deposition layer according to the target printing parameter, the printing material characteristic parameter and the geometric state parameter; judging whether the structural stability parameter meets a preset structural stability constraint condition or not; When the structural stability constraint condition is met, re-planning a printing path corresponding to the discrete deposition segment which is not executed yet according to the target printing parameter, and continuing to deposit materials according to the re-planned printing path; And when the structural stability constraint condition is not met, maintaining the current printing path or generating a structural compensation deposition path and continuing printing.
2. The method of claim 1, wherein the structural stability parameter comprises at least one of an interlayer vertical stress, an interlayer shear stress, and an overlap area between adjacent deposited layers, and The structural stability constraint includes: The interlayer vertical stress generated by the next deposition layer is not more than the green strength of the deposited layer material, the interlayer shearing stress generated by the next deposition layer is not more than the interlayer adhesion strength of the deposited layer material, and the overlapping area between the adjacent deposition layers is not less than the preset minimum bonding area threshold; Preferably, the interlayer vertical stress generated by the next deposition layer is calculated based on the density of the printing material, the volume of the next deposition layer and the gravity acceleration; Preferably, the interlayer shear stress generated by the next deposition layer is calculated based on the deposition path offset, the upper structure equivalent load and the interlayer effective bonding area.
3. The method of claim 1, wherein the printing material characteristic parameter comprises at least one of a viscosity, a yield stress, a density, a cure time, or a rheological model parameter; preferably, before the determining the structural stability parameter of the next deposited layer according to the target printing parameter, the printing material characteristic parameter, and the geometric state parameter, the structural stability determining operation further includes: the printing material characteristic parameter is modified based on the ambient temperature and/or the ambient humidity.
4. The method of claim 1, wherein the structural state data is acquired by a multi-modal sensor comprising at least one of a vision sensor, a laser displacement sensor, and a pressure sensor.
5. The method of claim 1, wherein the geometry parameters include at least one of a deposition layer height, a deposition width, a deformation amount, or a center offset; preferably, the printing nozzle is a printing nozzle with a variable discharging cross-sectional area, and the target printing parameters comprise adjusting parameters of the discharging cross-sectional area; Preferably, the structure compensating deposition path is a support deposition path for reducing the bending moment of the overhang structure; Preferably, the print parameter change request is a print parameter change request input by the target user through a voice or tactile input device input by a sound collection apparatus.
6. The method of claim 1, wherein the 3D printer further comprises a color-spraying device for spraying color on the printed article in real time during printing; The color spraying device comprises N groups of color spraying components, N is a positive integer, each group of color spraying components comprises an air source, an electronic throttle valve, an electromagnetic valve, a negative pressure generator, a color feeding port, a pigment spray head and a pigment storage device which are sequentially communicated, wherein: each electronic throttle valve and each electromagnetic valve are electrically connected with the control system; The electronic throttle valve is used for controlling the size of the air inflow entering the inlet of the electronic throttle valve from a corresponding air source; the electromagnetic valve is used for realizing the on-off control of the air flow from the corresponding electronic throttle valve to the corresponding negative pressure generator; the negative pressure generator is used for sucking pigment from the corresponding pigment storage device into the corresponding pigment feed inlet and sending the pigment into the corresponding pigment spray head; the extending lines of the extending directions of the pigment spray heads are intersected with the extending lines of the extending directions of the printing spray heads; preferably, the method further comprises: Responding to a received request for starting color spraying, and controlling the color spraying device to spray color according to the color indicated by the request for starting color spraying; preferably, the method further comprises: And controlling the color spraying device to finish color spraying in response to receiving the request for finishing color spraying.
7. A 3D printer, comprising: The motion executing mechanism is used for driving the printing spray head to spatially move relative to the printing platform; The material deposition mechanism is used for extruding printing materials according to set printing parameters to form a layer-by-layer deposition structure; The state sensing mechanism is used for collecting structure state data of the printed structure; a user input mechanism for inputting a print parameter change request during printing, and A control system, wherein the control system comprises: The path generation unit is used for generating an initial printing path according to the printing request information of the target user, dividing the initial printing path into a plurality of continuous discrete deposition segments, and each discrete deposition segment corresponds to a group of printing parameters; A deposition control unit for controlling the material deposition mechanism and the motion execution mechanism to perform material deposition segment by segment according to the sequence of each discrete deposition segment in the initial printing path; A state calculation unit, configured to obtain structural state data of a printed structure when a print parameter change request is received in a process of performing material deposition on a current discrete deposition segment, and determine a geometric state parameter of the printed structure based on the structural state data; The structure stability judging unit is used for determining a changed target printing parameter based on the current printing parameter and the printing parameter changing request, determining a structure stability parameter of a next deposition layer according to the target printing parameter, the printing material characteristic parameter and the geometric state parameter; The path reconstruction unit is used for carrying out re-planning on the printing path corresponding to the discrete deposition section which is not executed yet according to the target printing parameter when the structural stability constraint condition is met, and continuing to carry out material deposition according to the printing path after re-planning; a compensation control unit for maintaining a current printing path or generating a structural compensation deposition path when the structural stability constraint condition is not satisfied; And the control system controls the motion executing mechanism and the material deposition mechanism to continue printing according to the re-planned or compensated printing path.
8. The 3D printer of claim 7, wherein the status sensing mechanism is a multi-modal sensor comprising at least one of a vision sensor, a laser displacement sensor, and a pressure sensor; preferably, the printing nozzle is a printing nozzle with a variable discharging cross-sectional area, and the target printing parameters comprise adjusting parameters of the discharging cross-sectional area; Preferably, the user input mechanism comprises a sound collection device and/or a tactile input means.
9. The 3D printer of claim 7, wherein the 3D printer further comprises: the color spraying device comprises N groups of color spraying components, wherein N is a positive integer, each group of color spraying components comprises an air source, an electronic throttle valve, an electromagnetic valve, a negative pressure generator, a color feeding port, a pigment spray head and a pigment storage device which are sequentially communicated, and the color spraying components comprise: each electronic throttle valve and each electromagnetic valve are electrically connected with the control system; The electronic throttle valve is used for controlling the size of the air inflow entering the inlet of the electronic throttle valve from a corresponding air source; the electromagnetic valve is used for realizing the on-off control of the air flow from the corresponding electronic throttle valve to the corresponding negative pressure generator; the negative pressure generator is used for sucking pigment from the corresponding pigment storage device into the corresponding pigment feed inlet and sending the pigment into the corresponding pigment spray head; And the extension lines of the extension directions of the pigment spray heads are intersected with the extension lines of the extension directions of the printing spray heads.
10. The 3D printer of claim 9, wherein the control system further comprises: and the color spraying control unit is used for responding to the received request for starting color spraying, controlling the color spraying device to spray color according to the color indicated by the request for starting color spraying, and controlling the color spraying device to finish color spraying in response to the received request for finishing color spraying.

Description

3D printing method and 3D printer Technical Field The embodiment of the disclosure relates to the technical field of additive manufacturing, in particular to a 3D printing method and a 3D printer for path re-planning based on structural stability judgment in a printing process. Background Existing 3D printing techniques typically include three stages, model building, slicing processing, and layer-by-layer deposition printing. Before printing starts, a three-dimensional model is established through computer aided design software, and a corresponding printing path and printing parameters are generated through slicing software to form an executable printing instruction sequence. In the printing process, the printer deposits materials layer by layer according to preset paths and parameters to form a three-dimensional structure. However, in actual printing processes, especially when printing with slurries, clay, cement-based materials, or other semi-fluid materials, the stability of the deposited structure is affected by a number of factors, including material density, viscosity, yield stress, interlayer adhesion, ambient temperature and humidity, and deposition geometry, among others. When printing parameters (such as layer height, deposition width, path offset, or throughput) are changed, interlayer vertical or shear stresses are easily caused to exceed the material carrying capacity, resulting in structural collapse, slippage, or interlayer bond failure. In the prior art, the print path and print parameters are usually determined before the printing starts, and cannot be changed in the printing process. It is desirable to provide a 3D printing apparatus and a printing control method that can suspend execution of other instructions in printing. In addition, if the subsequent instruction is simply suspended or directly modified, the lack of a real-time analysis and determination mechanism for the stress state of the structure after the change easily causes printing failure or material waste. Therefore, how to respond to the dynamic adjustment requirement of the user on the printing parameters in the printing process, and combine the geometric state and the material characteristics of the printed structure to judge the structural stability of the changed deposition structure, and re-plan the printing path on the premise of meeting the stability condition, thereby realizing the 3D printing control scheme which can dynamically regulate and control and ensure the structural stability, and becoming the technical problem to be solved urgently. Disclosure of Invention The embodiment of the disclosure provides a 3D printing method and a 3D printer, which are used for solving the problems that a printing path is usually fixedly generated before printing in the existing 3D printing technology, and is difficult to adjust in real time according to structural stability in the printing process, so that the problems of collapse of a deposition structure, interlayer slippage or interlayer bonding failure and the like are easily caused under the condition of dynamic change of printing parameters. In a first aspect, embodiments of the present disclosure provide a 3D printing method, applied to a control system of a 3D printer, the method including: Generating an initial printing path according to printing request information of a target user, and dividing the initial printing path into a plurality of continuous discrete deposition segments, wherein each discrete deposition segment corresponds to a group of printing parameters; controlling the 3D printer to perform material deposition segment by segment according to the sequence of each discrete deposition segment in the initial printing path; In the process of carrying out material deposition on the current discrete deposition section, when a printing parameter change request is received, the following structure stability judging operation is carried out: Acquiring structural state data of a printed structure, and determining geometric state parameters of the printed structure based on the structural state data; determining a changed target printing parameter based on the current printing parameter and the printing parameter changing request; determining a structural stability parameter of a next deposition layer according to the target printing parameter, the printing material characteristic parameter and the geometric state parameter; judging whether the structural stability parameter meets a preset structural stability constraint condition or not; When the structural stability constraint condition is met, re-planning a printing path corresponding to the discrete deposition segment which is not executed yet according to the target printing parameter, and continuing to deposit materials according to the re-planned printing path; When the structural stability constraint condition is not met, printing is continued after the current printing path is maintained or the structural co