CN110744817A

CN110744817A - 3D printer material flow prevention device and printing method

Info

Publication number: CN110744817A
Application number: CN201911053466.7A
Authority: CN
Inventors: 汪馗; 赵安东; 张洪浩; 王琎; 谢训; 吴嘉唯
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2020-02-04
Anticipated expiration: 2039-10-31
Also published as: CN110744817B

Abstract

The invention belongs to the technical field of printing equipment and control, and discloses a 3D printer material flow prevention device and a printing method. The system control module controls the working spray head to print a layer of detection sample at a specified position, and then the working spray head moves to a product printing position to start printing a product; according to the invention, the height between the double spray heads and the printing bottom plate is automatically adjusted, mixed printing of different materials can be realized, and the influence of the flow on the product can be avoided by printing the detection sample, so that the printing quality is improved.

Description

3D printer material flow prevention device and printing method

Technical Field

The invention belongs to the technical field of printing equipment and control, and particularly relates to a 3D printer flow-preventing device and a printing method. In particular to an FDM type double-nozzle 3D printer flow-preventing device and a printing method.

Background

Currently, the closest prior art:

3D printing is used in various industries and is a technology for manufacturing products by a layer-by-layer printing method, among which fused deposition type technology (FDM) is most widely used, which is based on a digital model, heats a bondable material such as thermoplastic to a molten state, and achieves the purpose of constructing a three-dimensional entity in such a way that the material is extruded during the movement of a printing head and rapidly solidified after being bonded with the surrounding material.

With the development of 3D printing technology, it has become a development trend to optimize product performance through multi-material mixed printing, shorten production time, and reduce manufacturing cost. At present, in a double-nozzle 3D printer which is put into use, the height of each nozzle cannot be adjusted and is positioned on the same horizontal plane. And, the shower nozzle independent work when actually printing, when a shower nozzle is in the printing state, another shower nozzle is idle and along with the horizontal motion of operating condition shower nozzle together. Due to human assembly errors, the two nozzles have a certain height difference, and the non-working nozzles scratch the surface of the sample in the same layer printing process. In addition, because the temperature of the non-working spray head is always kept at a set value in the printing process, materials can flow out of the spray head under the high-temperature condition, namely, the material flowing phenomenon is caused, when the spray head moves to the edge of a sample, the material flows onto the edge of a product, and particularly, in the same-layer printing process, the spray head passes through the edge of the product for many times, so that the material flows onto the product repeatedly, and the printing quality is seriously influenced. Another problem caused by the flow phenomenon is: when the non-printing nozzle is switched to the printing state, due to the influence of the material flow, the situation of insufficient material supply can be caused initially, namely, no material is generated on the surface of the product at the time, and the printing defect of the product is caused. Therefore, the scratch and the flow phenomena caused by the unadjustable height of the spray head are the main restricting factors of the multi-material mixed printing, aiming at the problems,

the patent of publication number CN 207432783U discloses a 3D printer dual spray head basis device, and the device is through adding the stopper, and accurate control two shower nozzles mounting height is in unanimity, avoids cutting between shower nozzle and the printed product and grazes the interference, and consequently, the device structure that this patent proposed is complicated, the installation is difficult to, and this patent does not consider the influence of material to the product.

The patent of publication number CN 104960340 a discloses a 3D printer multi-nozzle interference-free printing method and a printing structure thereof, the nozzle structure changes the relative height difference of two nozzles in the printing process through small-angle inclination, and avoids the influence of a non-working nozzle on the printed sample, however, due to the limitation of the installation position, the distance between the inclined nozzle and the working plane is only 0.4-0.8mm, and the height range cannot solve the influence of the material flow on the sample surface in the long-time printing process.

The patent of publication No. CN 207156460U discloses a 3D beats printer head's anti-flow device, and the device utilizes and installs portable sphere gyro wheel in non-work shower nozzle department, blocks up non-work shower nozzle discharge gate, prevents the influence of material flow to printing sample surface. However, the patent specification does not mention the use of the device in a dual head printer, that is to say not suitable for mixed printing of multiple materials. In addition, the roller and the spray head repeatedly contact for a long time to cause the wear of the spray head, and the precision and the service cycle of the spray head are reduced.

In view of the above, at least one of the above-mentioned problems of the prior art inventions cannot be solved.

In summary, the problems of the prior art are as follows:

(1) at present, the horizontal heights of double nozzles are inconsistent due to installation errors or external disturbance in the multi-material mixed printing process, so that the non-working nozzles scrape the surface of the printed part of a product when moving along with the working nozzles, and the printing defect is caused.

(2) The spray head in a non-working state can generate flow in the printing process, and the flow can be adhered to a product along with the movement of the spray head, so that the appearance quality of the product is influenced.

(3) Another problem caused by the flow phenomenon is: when the nozzles are alternately printed, the nozzles which are changed from a non-working state to a working state are enabled not to extrude materials at the initial printing stage due to material flowing, so that the printing defects are caused, and the performance of the product is influenced.

The significance of solving the technical problems is as follows:

in view of the above situation, the invention provides a 3D printer material flow prevention device and a printing method, which can adjust the height value of a nozzle in real time according to the printing requirement, and not only can realize automatic adjustment of the height of double nozzles and avoid the influence of material flow on the product, but also bring the following meanings:

the device and the printing method can meet the market demands of high-mixing printing of different materials and different layers, and have great significance in achieving high-precision batch production of products, improving the reliability of multi-material mixing printing, promoting the 3D printing technology to develop towards the direction of comprehensive automation, achieving the goals of rapid printing and the like.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a 3D printer flow-preventing device and a printing method.

The invention is realized like this, a 3D printer prevents the material flow device, including:

the spray head structure: comprises a feeding pipe, a throat pipe, a radiating fin, a spray head, a spring and a spring upper stop; the upper end of the throat pipe is provided with a spring and an upper spring stop, the upper spring stop is connected with the upper end of the throat pipe through threads, and the middle part of the throat pipe is provided with a radiating fin;

heating block: for heating the material to a molten state; the heating block is connected with the lower end of the throat pipe through threads;

the spray head is fixed at the lower end of the heating block through threaded connection; the lower part of the throat pipe is connected with the upper end of the heating block, and the lower end of the heating block is connected with the spray head;

the shifting fork structure: the device comprises a shifting fork, a forward and reverse rotating stepping motor, a shifting fork positioning seat, a motor seat, a cam 1 and a cam 2; a motor base is arranged on the outer side of the stepping motor, a shifting fork positioning seat is arranged on the outer side of the shifting fork, a cam is arranged at the rear end of the shifting fork, the cam is fixed on a motor spindle, and the front section of the shifting fork is in contact with an upper stop of a spring; the cam 1 and the cam 2 are fixed on a main shaft of the stepping motor and are arranged at a certain angle, the upper stop of the spring and the cam are respectively contacted with two ends of a shifting fork, and the shifting fork swings up and down along with the rotation of the cam to control the sprayer mechanism to move up and down.

Further, the flow device is prevented to 3D printer further includes: a base and an infrared distance measuring device;

the lower end of the base is provided with an infrared distance measuring device which moves up and down along with the spray head structure.

Another object of the present invention is to provide a printing method comprising the steps of:

firstly, a printer data reading and analyzing module reads a printing slice file;

secondly, compensating the height of the spray head;

thirdly, printing the product according to the instruction of the system control module;

and step four, the data reading and analyzing module judges whether the printing of the file is finished.

Further, in step one, the file includes: printing layer height and printing nozzle necessary printing parameters appointed by a printing area.

Further, the second step specifically comprises:

the method comprises the following steps that firstly, a system control module controls a printing bottom plate to descend to a default Z-axis position of a system, an infrared ranging module on a specified working spray head structure measures the height value of the printing spray head from the printing bottom plate, and a data reading and analyzing module compares and analyzes the height value with the set first layer printing layer height to obtain a height difference value;

secondly, the spray head height adjusting module controls a stepping motor to drive a cam to rotate according to the obtained height difference value, so that the corresponding shifting fork rotates for a certain angle, and the height compensation of the spray head is realized; when the working nozzle moves to a designated height, the non-working nozzle is far away from the printing surface, and the maximum height difference of the two nozzles is determined by the structures of the throat pipe and the cam.

Further, the third step specifically comprises: the working nozzle prints a layer of detection sample at a designated position according to an instruction of the system control module, and then the working nozzle moves to a product printing position to start printing a product;

when the work shower nozzle began to print and detects the sample, the stream material that produces at idle period work shower nozzle bonds to detecting the sample surface, does not influence the quality of printing the product to the structure of detecting the sample guarantees that the nozzle under the condition that can extrude the material, moves the product and prints the region, prints the product. The printing defect caused by insufficient extrusion of the material in the initial period of the printing work is avoided.

Further, the data reading and analyzing module judges whether the printed file is completed, if so, the system control module finishes printing; and if not, the data reading and analyzing module reads the next layer height, the system control module enables the printing bottom plate to descend to the same height, the infrared distance measuring device on the appointed printing nozzle detects the height value of the spray head from the printing bottom plate, the data reading and analyzing module compares the height value increment of the spray head from the printing bottom plate with the layer height (the influence of the change of the spray head height caused by external disturbance on sample printing is avoided), and the step two and the step three are repeated until the printing is finished.

Another object of the present invention is to provide an information data processing terminal implementing the printing method.

Another object of the present invention is to provide a computer-readable storage medium including instructions which, when run on a computer, cause the computer to execute the printing method.

Another object of the present invention is to provide a print control system for implementing the printing method, characterized by comprising:

a system control module: controlling the printing bottom plate to ascend and descend and the spray head to move according to the printing slice file;

infrared ray range finding module: detecting the height value of the spray head from the printing bottom plate;

a data reading and analyzing module: reading printing slice data and analyzing the relation between the height value of the spray head and the printing bottom plate detected by the infrared ranging module and the layer height, and judging the printing completion condition;

the spray head height adjusting module: and the cam is controlled to rotate by a certain angle according to the data reading and analyzing module to drive the spray head structure to move up and down, so that the height compensation of the spray head is realized.

In summary, the advantages and positive effects of the invention are:

the printer data reading and analyzing module provided by the invention reads the printing slice file; the system control module drops the printing bottom plate to a default Z-axis position of the system, an infrared distance measuring device on a designated working spray head detects the height value of the printing spray head from the printing bottom plate, and after the height value and the set layer height are compared and analyzed by a data reading and analyzing module to obtain a height difference value, a spray head height adjusting module controls a stepping motor to drive a cam to rotate, so that a corresponding shifting fork rotates for a certain angle, and the height compensation of a nozzle is realized; the system control module controls the working spray head to print a layer of detection sample at a specified position, and then the working spray head moves to a product printing position to start printing a product; the data reading and analyzing module judges whether the printing of the file is finished or not; until the printing is finished. According to the invention, the double spray heads can automatically adjust the height of the spray heads from the printing bottom plate, so that different materials can be mixed and printed, and the influence of the flow on the product can be avoided by printing the detection sample, thereby improving the printing quality.

Compared with the prior art, the invention has the advantages that:

the 3D printer flow-preventing device and the printing method provided by the invention are suitable for mixed printing of different materials. In the printing process, the shifting fork is driven to swing through the rotation of a cam on a main shaft of a stepping motor in the shifting fork mechanism, so that the printing height of the working nozzle is accurately controlled. Meanwhile, the non-working spray head controlled by the shifting fork mechanism is far away from the printing surface, so that the spray head is prevented from scratching the surface of the sample, and the flow is prevented from being bonded to the surface of a printed product in the printing process, and the quality of the product can be improved. When the double nozzles are used alternately, a layer of detection sample is printed in advance at the initial printing stage of each layer of the product, so that the flow generated when the nozzle switched to the working state is in the non-working state can be adhered to the surface of the detection sample; the printing detection sample can ensure that the nozzle can print the product when the material can be completely extruded, and the influence of the flow on the product in the process of mixing and printing different materials is solved.

The automatic double-nozzle height adjusting device provided by the invention can guarantee the printing precision and avoid printing midway failures. The infrared ranging module measures the height of the spray head from the printing bottom plate before each layer of detection samples are printed, so that the printing precision is accurately controlled, and the product quality requirement is met.

Drawings

Fig. 1 is a flowchart of a printing method of an FDM type dual-nozzle 3D printer anti-flow device provided in an embodiment of the present invention.

Fig. 2 is a schematic diagram of a printing method of the anti-flow device of the FDM type dual-nozzle 3D printer provided in the embodiment of the present invention.

Fig. 3 is a schematic structural view of a flow prevention device of an FDM-type dual-nozzle 3D printer provided in an embodiment of the present invention.

Fig. 4 is a schematic structural diagram of a shifting fork mechanism provided by the embodiment of the invention.

Fig. 5 is a cross-sectional view of the assembly of the upper spring stop according to an embodiment of the present invention.

Fig. 6 is a schematic diagram of a printing control system according to an embodiment of the present invention.

In the figure: 1. a stepping motor; 2. a cam; 3. a throat; 4. a spring upper stop; 5. a shifting fork positioning seat; 6. a heating block; 7. a nozzle; 8. an infrared distance measuring device; 9. a heat sink; 10. a spring; 11. a shifting fork; 12. a motor base; 13. a feed pipe; 14. a base; 15. a system control module; 16. an infrared ranging module; 17. a data reading and analyzing module; 18. and a spray head height adjusting module.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following 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 the prior art, in the process of printing different materials in a mixed manner, the stepping motor drives the shifting fork to automatically adjust the height of the spray head assembly from the bottom plate, so that the problem that the flow material influences the product in the printing process cannot be avoided

Aiming at the problems in the prior art, the invention provides an automatic height adjusting system and a control method for an FDM type double-nozzle 3D printer, and the invention is described in detail below with reference to the accompanying drawings.

As shown in fig. 1, a printing method of an FDM-type dual-nozzle 3D printer anti-flow device provided in an embodiment of the present invention includes:

s101: the printer data reading analysis module reads a print slice file (G-Code) including: printing layer height, designated printing nozzle and other necessary printing parameters.

And S102, ①, lowering the printing bottom plate of the system control module to a default Z-axis position of the system, detecting the height value of the printing spray head from the printing bottom plate by an infrared distance measuring device on the appointed working spray head, comparing the height value with the set first-layer printing layer height by the data reading and analyzing module, analyzing the result to obtain a height difference value, and controlling a stepping motor to drive a cam to rotate by the ② spray head height adjusting module according to the obtained height difference value so as to enable a corresponding shifting fork to rotate by a certain angle and realize the height compensation of the nozzle.

S103: and the working spray head prints a layer of detection sample at a specified position according to an instruction of the system control module, and then the working spray head moves to a product printing position to start printing the product.

S104, the data reading and analyzing module judges whether the printing file is finished, if so, the system control module controls to finish printing, if not, the data reading and analyzing module reads the height value of the next printing layer, meanwhile, the system control module enables the printing bottom plate to descend to the height, an infrared distance measuring device on the appointed printing nozzle detects the height value of the spray head from the printing bottom plate, the data reading and analyzing module compares the increment of the height value of the spray head from the printing bottom plate with the layer height, and S102 ② and the subsequent steps are repeated until the printing is finished.

As shown in fig. 2, a printing method principle of the anti-flow device of the FDM type dual-nozzle 3D printer provided by the embodiment of the present invention is provided.

As shown in fig. 3, an embodiment of the present invention provides an FDM type 3D printer anti-flow device, including: the device comprises a stepping motor 1, a cam 2, a throat pipe 3, a spring upper stop 4, a shifting fork positioning seat 5, a heating block 6, a nozzle 7, an infrared distance measuring device 8, a cooling fin 9, a spring 10, a shifting fork 11 and a motor seat 12.

And (6) heating block: primarily to heat the material to a molten state.

Infrared distance measuring device 8: the module is fixedly connected with a printing spray head structure, can move up and down along with the printing spray head, and mainly measures the real-time distance between the printing spray head and a printing bottom plate or a printing surface.

Left and right nozzle structure: the structure consists of a throat pipe 3, an upper spring stop 4, a nozzle 7, a radiating fin 9, a spring 10 and a feeding pipe 13, wherein the upper spring stop 4 is in threaded connection with the throat pipe 3.

Fork structure (as shown in fig. 3): the structure comprises a forward and reverse rotation stepping motor 1, a shifting fork positioning seat 5, a shifting fork 11, a motor seat 12, a cam 1 and a cam 2, wherein the cam 1 and the cam 2 are fixed on a main shaft of the stepping motor and are arranged at a certain angle; the spring upper stop 4 (as shown in fig. 5) and the cam 2 are respectively contacted with two ends of the shifting fork 11, and the shifting fork 11 swings up and down along with the rotation of the cam 2, so that the sprayer mechanism is controlled to move up and down.

As shown in fig. 6, an embodiment of the present invention provides an FDM type 3D printer anti-flow device, including: the system comprises a system control module 15, an infrared ranging module 16, a data reading and analyzing module 17 and a spray head height adjusting module 18.

The system control module 15: and controlling the printing bottom plate to ascend and descend and the spray head to move according to the printing slice file.

Infrared ray ranging module 16: and detecting the height value of the spray head from the printing bottom plate.

Data reading analysis module 17: and reading the printing slice data and analyzing the relation between the height value and the layer height of the spray head detected by the infrared ranging module and the printing bottom plate, and judging the printing completion condition.

The nozzle height adjustment module 18: and the cam is controlled to rotate by a certain angle according to the data reading and analyzing module to drive the spray head structure to move up and down, so that the height compensation of the spray head is realized.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When used in whole or in part, can be implemented in a computer program product that includes one or more computer instructions. When loaded or executed on a computer, cause the flow or functions according to embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions may be transmitted from one website site, computer, server, or data center to another website site, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL), or wireless (e.g., infrared, wireless, microwave, etc.)). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that includes one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. The utility model provides a flow material device is prevented to 3D printer, its characterized in that, flow material device is prevented to 3D printer includes:

2. The 3D printer flow prevention device of claim 1, wherein the 3D printer flow prevention device further comprises: a base and an infrared distance measuring device;

3. A printing method of the 3D printer anti-flow device according to claim 1, characterized in that the printing method comprises the following steps:

secondly, compensating the height of the spray head;

4. The printing method of claim 3, wherein in step one, the document comprises: printing layer height and printing nozzle necessary printing parameters appointed by a printing area.

5. The printing method according to claim 3, wherein step two specifically comprises:

6. The printing method according to claim 3, wherein step three specifically comprises: the working nozzle prints a layer of detection sample at a designated position according to an instruction of the system control module, and then the working nozzle moves to a product printing position to start printing a product;

when the work shower nozzle began to print and detects the sample, the stream material that produces at idle period work shower nozzle bonds to detecting the sample surface, does not influence the quality of printing the product to the structure of detecting the sample guarantees that the nozzle under the condition that can extrude the material, moves the product and prints the region, prints the product.

7. The printing method according to claim 3, wherein the data reading analysis module of step four judges whether the printing document is completed, if yes, the system control module finishes printing; and if not, the data reading and analyzing module reads the next layer height, the system control module enables the printing bottom plate to descend to the same height, the infrared distance measuring device on the appointed printing nozzle detects the height value of the spray head from the printing bottom plate, the data reading and analyzing module compares the height value increment of the spray head from the printing bottom plate with the layer height, and the step two and the step three are repeated until the printing is finished.

8. An information data processing terminal for implementing the printing method according to any one of claims 3 to 7.

9. A computer-readable storage medium comprising instructions which, when executed on a computer, cause the computer to perform the printing method of any one of claims 3-7.

10. A print control system for implementing the printing method according to claim 3, the print control system comprising: