阅读说明：本技术 一种基于机械臂的单次多材料3d打印机构 (Single multi-material 3D printing mechanism based on mechanical arm ) 是由 骆汉宾 张佳乐 龚翔宇 尹紫微 于 2020-06-24 设计创作，主要内容包括：本发明属于3D打印领域,并具体公开了一种基于机械臂的单次多材料3D打印机构,其包括数据处理系统、控制系统、动力系统、机械臂和挤出系统,其中：所述数据处理系统用于根据材料特性预设打印路径；所述控制系统用于通过所述动力系统和机械臂控制所述挤出系统按预设打印路径进行打印；所述挤出系统包括多喷嘴组件,该多喷嘴组件安装在所述机械臂末端,其包括多个相互独立的单喷嘴单元,每个所述单喷嘴单元均包括相互连接的打印喷嘴和储料斗,所述打印喷嘴的直径各不相同。本发明将建模软件与机械臂相结合,同时对多喷嘴组件进行设计,实现以单次固定移动速度为基础对异直径的多喷嘴挤出速率进行调整,同时提高了打印精度和打印速度。(The invention belongs to the field of 3D printing, and particularly discloses a single-time multi-material 3D printing mechanism based on a mechanical arm, which comprises a data processing system, a control system, a power system, the mechanical arm and an extrusion system, wherein: the data processing system is used for presetting a printing path according to material characteristics; the control system is used for controlling the extrusion system to print according to a preset printing path through the power system and the mechanical arm; the extrusion system comprises a multi-nozzle assembly, the multi-nozzle assembly is arranged at the tail end of the mechanical arm and comprises a plurality of independent single-nozzle units, each single-nozzle unit comprises a printing nozzle and a storage hopper which are connected with each other, and the diameters of the printing nozzles are different from each other. According to the invention, modeling software is combined with the mechanical arm, and the multi-nozzle assembly is designed, so that the extrusion speed of the multi-nozzles with different diameters is adjusted on the basis of a single fixed moving speed, and meanwhile, the printing precision and the printing speed are improved.)

1. A single multi-material 3D printing mechanism based on a mechanical arm is characterized by comprising a data processing system, a control system, a power system, the mechanical arm and an extrusion system, wherein:

the data processing system is used for presetting a printing path according to material characteristics;

the control system is used for controlling the extrusion system to print according to a preset printing path through the power system and the mechanical arm;

the extrusion system comprises a multi-nozzle assembly, the multi-nozzle assembly is arranged at the tail end of the mechanical arm and comprises a plurality of independent single-nozzle units, each single-nozzle unit comprises a printing nozzle and a storage hopper which are connected with each other, and the diameters of the printing nozzles are different from each other.

2. The robotic-based single pass multi-material 3D printing mechanism as claimed in claim 1, wherein the data processing system includes a "travel rate-material type-nozzle diameter interval" matching database, and the diameter of each print nozzle is determined by inputting the travel rate and material type into the matching database to obtain the nozzle diameter interval.

3. The robotic-arm-based single pass multi-material 3D printing mechanism of claim 1, wherein the power system includes a plurality of direct power units in one-to-one correspondence with the single nozzle units; the direct power unit comprises a motor and a worm which are connected, and the motor drives the worm to convey materials from the storage hopper to the printing nozzle.

4. The robotic-arm-based single-shot multi-material 3D printing mechanism as claimed in claim 1, wherein a print nozzle switch is provided at the print nozzle outlet, the print nozzle switch being controlled by the control system for automatically switching the print nozzle to prevent material spillage.

5. The robotic-based single pass multi-material 3D printing mechanism of claim 1, wherein the storage hopper is inclined at an angle of 45 ° to the outer wall of the print nozzle.

6. The robotic-based single pass multi-material 3D printing mechanism as claimed in claim 1, wherein all of the print nozzles are fixed to the same straight tube that is fixed to the robotic arm.

7. The robotic-based single-pass multi-material 3D printing mechanism of claim 1, wherein the hopper is connected to the print nozzle by a feed conduit, and a connecting sleeve is provided between the hopper and the feed conduit and between the feed conduit and the print nozzle.

8. The robotic-based single pass multi-material 3D printing mechanism as recited in claim 1, wherein an agitator is disposed within the storage hopper for agitating material within the storage hopper and a dust hose for discharging dust within the storage hopper.

9. The robotic arm-based single pass multi-material 3D printing mechanism as recited in claim 1, wherein the print nozzle is made of a stainless steel material.

10. The robotic-arm-based single-shot multi-material 3D printing mechanism as in any one of claims 1-9, wherein the number of single nozzle units is 3-5.

Technical Field

The invention belongs to the field of 3D printing, and particularly relates to a single-time multi-material 3D printing mechanism based on a mechanical arm.

Background

The 3D printing is a new manufacturing technology for manufacturing solid objects by stacking materials layer by layer on the basis of a digital model, deeply influences the traditional process flow, production line, factory mode and industrial chain combination, is a representative subversive technology of the manufacturing industry, and has been widely applied to industries such as industrial machinery, aerospace and the like. The 3D concrete printing technology is still immature and has not reached a fully generalizable stage. In the building field, due to factors such as materials and sizes, a common extrusion type 3D printer only comprises a single nozzle, and prints one material at a time, and has problems of slow printing speed, printing of a material list and the like.

Zhang from strong etc. on the basis of in-depth research 3D printer mechanism, fully consider the problem in aspects such as shaping precision and shaping speed of current extrusion mechanism, carried out design improvement to 3D printer extrusion mechanism, established novel three nozzle extrusion mechanism model, thereby carry out virtual design through three-dimensional modeling software and obtain optimum design model.

The novel concrete 3D printing device is developed by the extrusion curing printing technology in the 3D printing process of the building, integrated numerical control technology, mechanical technology, computer technology and the like, and the device is composed of modules such as a control mechanism, an XYZ motion mechanism, an extrusion mechanism, a data processing mechanism and the like, has a good integrated control function, and can complete the materialized construction of a building information model.

Wu Shaohang et al propose a method of controlling asynchronous multi-nozzle collaborative printing, the method comprising the steps of: the host print engine program generates print data and control information and transmits them separately to the print motherboard controller. The printing data enters a command analysis and data distribution module in the printing mainboard controller through a data channel of the printing mainboard controller, the command analysis and data distribution module distributes the printing data of each nozzle to a respective first-stage buffer FIFO, then the printing data is saved in an independent data area of a memory SDRAM after read-write arbitration of the memory controller, the printing data which is requested to be read out from the memory controller is temporarily stored in the second-stage buffer FIFO of each nozzle along with the arrival of trigger signals of each nozzle, and finally the printing data is sent to the nozzles by each nozzle driving module.

Shenhong 22426: (1) using four triaxial mechanical arms as cooperative three-dimensional printing equipment to determine the placement positions of the mechanical arms; (2) exporting a G code file of the three-dimensional model from open source printing software according to the mechanical arm parameters, and dividing the G code file into four independent G code files by using dividing lines according to a printing time consistency criterion; (3) setting the interference size of the mechanical arm by taking the mechanical arm end effector as a reference, and dividing each independent G code file into a safety area and an interference area; (4) setting a scheduling criterion when the mechanical arm executes a printing task, and ensuring that at most one mechanical arm can print in an interference area at the same time; (5) and printing the three-dimensional model layer by layer according to a scheduling criterion. The invention can improve the efficiency of multi-robot collaborative printing.

However, the above methods cannot simultaneously perform 3D printing on multiple building materials, and have the problems of slow printing speed, low efficiency and poor effect, so a multi-nozzle 3D printing mechanism and method capable of printing multiple materials at a time are needed.

Disclosure of Invention

Aiming at the defects or improvement requirements in the prior art, the invention provides a single multi-material 3D printing mechanism based on a mechanical arm, and aims to combine modeling software with the mechanical arm, endow a data processing system, a control system, a power system and an extrusion system with new integral functions, design a multi-nozzle assembly, and adjust the extrusion speed of multi-nozzles with different diameters on the basis of single fixed moving speed, so that the optimal effect of printing different materials at the same moving speed is ensured.

In order to achieve the above purpose, the present invention provides a single multi-material 3D printing mechanism based on a mechanical arm, which includes a data processing system, a control system, a power system, a mechanical arm and an extrusion system, wherein:

the data processing system is used for presetting a printing path according to material characteristics;

the control system is used for controlling the extrusion system to print according to a preset printing path through the power system and the mechanical arm;

The extrusion system comprises a multi-nozzle assembly, the multi-nozzle assembly is arranged at the tail end of the mechanical arm and comprises a plurality of independent single-nozzle units, each single-nozzle unit comprises a printing nozzle and a storage hopper which are connected with each other, and the diameters of the printing nozzles are different from each other.

Further preferably, the data processing system includes a "moving speed-material kind-nozzle diameter interval" matching database, and the nozzle diameter interval is acquired by inputting the moving speed and the material kind into the matching database, thereby determining the diameter of each printing nozzle.

As a further preference, the power system comprises a plurality of direct power units, and the direct power units correspond to the single nozzle units one by one; the direct power unit comprises a motor and a worm which are connected, and the motor drives the worm to convey materials from the storage hopper to the printing nozzle.

It is further preferred that a print nozzle switch is provided at the print nozzle outlet, the print nozzle switch being controlled by the control system for automatically switching the print nozzle on and off to prevent material spillage.

Further preferably, the storage hopper and the outer wall of the printing nozzle are inclined at an angle of 45 °.

It is further preferred that all of the print nozzles are fixed to the same straight tube, which is fixed to the robot arm.

As a further preferred option, the storage hopper is connected to the print nozzle through a feed pipe, and connecting sleeves are provided between the storage hopper and the feed pipe, and between the feed pipe and the print nozzle.

As a further preferred option, a stirrer and a dust removal hose are arranged in the storage hopper, the stirrer is used for stirring the materials in the storage hopper, and the dust removal hose is used for discharging the dust in the storage hopper.

As a further preference, the printing nozzle is made of stainless steel material.

More preferably, the number of the single nozzle units is 3 to 5.

Generally, compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:

1. the invention combines modeling software and a mechanical arm, gives an integral new function to a data processing system, a control system, a power system and an extrusion system, designs a multi-nozzle assembly, realizes the adjustment of the extrusion speed of the multi-nozzle with different diameters on the basis of single fixed moving speed, thereby ensuring the optimal effect of printing different materials at the same moving speed, even if the printing precision and the printing speed are simultaneously improved, can finish the 3D printing activity of various building material components at a time by using the mechanism of the invention, and saves the manual labor cost of about 1/3.

2. The multi-nozzle assembly improves the use efficiency of a printing space, and greatly enlarges the printing range on the basis of reducing the printing work area; the printing speed can be greatly increased by simultaneously printing the multiple nozzles, the modeling difficulty is simplified on the basis of ensuring the printing reliability and precision, and the construction surface roughness is reduced; meanwhile, the discharging time difference of different nozzles is short, the solidifying time of different materials is relatively close, the combination effect among the materials is better, and the improvement on the strength and the precision of a printing component is facilitated.

3. The printing nozzles are directly fixed on the same straight pipe, so that independent space movement does not exist during printing, and the printing precision loss caused by relative position change among the nozzles can be reduced.

4. According to the invention, the connecting sleeves are arranged among the storage hopper, the conveying pipe and the printing nozzle, so that the simple assembly and disassembly on the communicated basis are ensured, and the conveying pipe and the printing nozzle with different diameters can be conveniently replaced.

5. The storage hopper can realize the integration of stirring and extrusion of building materials, and can ensure that the building materials can keep better material performance for a longer time; meanwhile, materials are respectively conveyed to corresponding nozzles through the conveying pipes between the independent storage hoppers, so that mixed pollution among the materials can be avoided.

Drawings

FIG. 1 is a schematic structural diagram of a single-pass multi-material 3D printing mechanism based on a mechanical arm according to an embodiment of the invention;

FIG. 2 is a schematic structural diagram of a control system according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a power system according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an extrusion system according to an embodiment of the present invention;

FIG. 5 is a flowchart of a single-pass multi-material 3D printing workflow based on a robotic arm according to an embodiment of the present invention;

FIG. 6 is a schematic view of a multi-nozzle assembly according to an embodiment of the present invention;

FIG. 7 is a schematic structural view of a storage hopper according to an embodiment of the present invention;

FIG. 8 is a cross-sectional view of a single nozzle configuration in accordance with an embodiment of the present invention;

FIG. 9 is an enlarged view of a print nozzle switch according to an embodiment of the present invention.

The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein: 1-motor, 2-feed inlet, 3-worm, 4-dust removal hose, 5-storage hopper, 6-feed delivery pipe, 7-straight pipe, 8-discharge outlet, 9-connecting screw, 10-printing nozzle, 11-printing nozzle switch, 12-rotary platform, 13-electric rotary shaft, 14-nozzle outer cover, and 15-connecting sleeve.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The single-time multi-material 3D printing mechanism based on the mechanical arm, as shown in fig. 1, includes a data processing system, a control system, a power system, a mechanical arm, and an extrusion system, wherein:

the extrusion system comprises a printing nozzle switch 11 and a multi-nozzle assembly as shown in fig. 4, wherein the multi-nozzle assembly is mounted at the tail end of the mechanical arm and comprises a plurality of independent single nozzle units as shown in fig. 6, the number of the single nozzle units is preferably 3-5, the specific number is determined according to the type of a material contained in a model to be printed, each single nozzle unit comprises a printing nozzle 10 and a storage hopper 5, and the diameters of the printing nozzles 10 are different; the print nozzle switch 11 is arranged at the outlet of the print nozzle 10, the print nozzle switch 11 is controlled by the control system and is used for automatically switching the print nozzle 10 to prevent the material from overflowing, specifically, as shown in fig. 9, the print nozzle switch 11 comprises a rotating platform 12 and a nozzle outer cover 14, the rotating platform 12 is fixed on the print nozzle 10, and the nozzle outer cover 14 is connected with the rotating platform 12 through an electric rotating shaft 13 and can close or open the outlet of the print nozzle 10 through the electric rotating shaft 13;

Furthermore, all the printing nozzles 10 are screwed on the same straight pipe 7 through connecting screws 9, the straight pipe 7 is fixed at the tail end of a mechanical arm of the robot through a flange plate, and the moving printing process is completed by the movement of the mechanical arm; as shown in fig. 8, the printing nozzle 10 is made of a stainless steel material, and the printing nozzle 10 can be manually disassembled and replaced according to different printing materials;

further, the upper end of the storage hopper 5 is provided with a feeding hole 2, the lower end of the storage hopper is provided with a discharging hole 8, a stirrer and a dust removal hose 4 are arranged in the storage hopper 5, and the storage hoppers for storing different materials are mutually independent;

further, the storage hopper 5 is connected with the printing nozzle 10 through the material conveying pipe 6 and is used for extruding peptized mixtures of different building materials at the same time, and the diameters of the material conveying pipes 6 in the single nozzle units are different, so that the independent stirring and output of different materials during printing are ensured; as shown in fig. 7, connecting sleeves 15 are respectively arranged between the storage hopper 5 and the delivery pipe 6 and between the delivery pipe 6 and the printing nozzle 10, so that the simple assembly and disassembly on the basis of communication are ensured, and the replacement of delivery pipes and nozzles with different diameters is convenient;

further, the inclination angles alpha and beta of the printing nozzle 10 and the outer wall of the storage hopper 5 are set to be the empirical coefficient of 45 degrees, the length L of the printing nozzle 10 is 0.15m, and the diameter R of the material conveying pipe 6 is respectively determined according to different materials _i8-caliber D of discharge port_iAnd a pipe diameter R 'of the printing nozzle 10'_iAnd nozzle diameter D'_i(i is 1,2,3 …), and the electric rotating shaft 13 is spaced from the center of the nozzle cover 14

The data processing system performs material unit division, slicing layering processing and path planning on an STL file (the model is distinguished aiming at different materials during modeling) according to the requirements (different spatial relationships, material characteristics and the like) of different materials on the basis of finishing the function of the conventional single-material 3D printing modeling requirement, and converts the STL file into a numerical control program; specifically, the data processing system can be used for analyzing the STL file to generate a G code, and converting the G code into a recognizable robot code, so as to control the mechanical arm to print; the data processing system mainly realizes the following functions of (1) model display and division, (2) material matching, (3) data processing and (4) path simulation;

furthermore, the data processing function is realized by a layering algorithm and a filling algorithm which are built in the system, the layering algorithm adopts a layering processing algorithm based on the position information of a triangular patch, and the filling algorithm for path planning refers to documents;

further, the data processing system includes a "moving speed-material type-nozzle diameter interval" matching database, and the nozzle diameter interval is acquired by inputting the moving speed and the material type into the matching database, so as to determine the diameter of each printing nozzle.

The control system is used as a central part for reading numerical control programs to integrally control the on-off and operation of the power system, the mechanical arm and the extrusion system; specifically, as shown in fig. 2, the control system adopts a numerical control system capable of integrally controlling the motor, the control cabinet, the mechanical arm and the multi-nozzle assembly, and the numerical control system includes: the robot comprises a microprocessor, an external input module, a G code interpretation module, a linkage module, a mechanical signal processing module and a human-computer interaction interface, wherein the G code interpretation module can open an interface to access the robot, and the module is used for analyzing a code instruction input into the robot so as to realize uniform motion, position motion and zero returning motion between mechanical arm shafts.

The power system comprises a plurality of direct power units which are in one-to-one correspondence with the single nozzle units, as shown in fig. 3; the direct power unit comprises a motor 1 and a worm 3 which are connected, and the motor drives the worm to feed different materials into the printing nozzles from respective storage hoppers in an extrusion mode through a feed delivery pipe; the power system also comprises a PLC control cabinet, a frequency converter, an extrusion switch and a detection sensor, wherein the extrusion switch is controlled by a numerical control program and can manually adjust the pumping speed; the signal command sent by the control cabinet is transmitted to the extrusion switch by the control line for the flow control of the building material.

When the single multi-material 3D printing mechanism based on the mechanical arm works, as shown in FIG. 5, the method comprises the following steps:

s1, carrying out model design by using modeling software such as AUTOCAD, SolidWorks and the like, and outputting the model as an STL file;

s2, inputting material types and moving speed parameters in a data processing system, obtaining an optimal multi-nozzle diameter combination under the limitation of various materials by using a matching database of moving speed-material type-nozzle diameter interval, and replacing a corresponding printing nozzle and a corresponding conveying pipe according to the result;

s3, importing the STL file into a data processing system to divide different material units, inputting set parameters (moving speed, printing thickness, layering thickness and the like) to perform data processing such as slicing and path planning and outputting the data as a G code file;

s5, inputting a G code file on a human-computer interaction interface, and analyzing a code instruction input into the G code file by using a G code interpretation module to obtain a numerical control program for controlling the movement of the mechanical arm, the motor and the switch of the printing nozzle;

s6, after the pre-stirred materials are filled into different storage hoppers through the feeding hole, the direct power conveying unit and the robot are started to print, and in the printing process, the operation of each printing unit is cooperatively controlled through a numerical control program and different operation buttons of a human-computer interaction interface until the whole 3D printing process under multiple building materials is completed, so that a multi-material 3D printing product is generated.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.