Multi-laser two-way 3D printing method capable of achieving powder laying and printing at same time

Abstract

The invention discloses a multi-laser bidirectional 3D printing method capable of laying powder and printing at the same time, and belongs to the technical field of 3D printing, the method comprises the steps that firstly, the powder laying direction of current layer powder is judged, a powder working cavity is divided into sub-areas with the number equal to that of laser printing heads, and the widths of the sub-areas are gradually decreased in sequence according to the powder laying direction; and then, the powder laying mechanism carries out powder laying according to the powder laying direction of the current layer of powder, and after powder laying of a certain sub-area is completed, the printing task of the sub-area is distributed to the corresponding laser printing head for printing. According to the multi-laser 3D printing equipment capable of laying powder in two directions, the waiting time of each laser printing head is shortened, and the printing efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing, and in particular relates to a 3D printing method with multi-laser bidirectional powder spreading and printing. Background Art

[0002] Additive manufacturing, or 3D printing, is a technology that uses digital model files as a foundation to create objects by printing metal, plastic, ceramic, sand, and other adhesive materials layer by layer. This technology breaks through the processing limitations of traditional processes and can quickly form parts with complex structures. Depending on the type of consumables and the feeding method, the technology used in 3D printing devices varies, including: Stereolithography (SLA), Selective Laser Melting (SLM), and Selective Laser Sintering (SLS). Both SLS and SLM processes are based on layering powder and then using a heat source such as a laser to sinter or clad the powder.

[0003] The powder spreading mechanism of existing 3D printing equipment primarily consists of a scraper, a powder feeder, and a recovery chamber. The printing process proceeds as follows: the scraper applies a layer of powder material to the upper surface of the finished part. A laser beam scans the part's cross-sectional contours, sintering the current layer of powder. This layer then automatically bonds to the finished part below. Once a layer of cross-section has been sintered, the worktable descends by one layer, and the scraper applies another layer of powder material, sintering the next layer until the entire model is complete.

[0004] During the printing process, a scraper is used to spread powder after each layer is printed. Printing stops during this period, and the next layer can only be printed after the powder is spread. In traditional single-laser printing equipment, the printing time for each layer is much longer than the powder spreading time, so the time lost in powder spreading has limited impact. As 3D printing equipment enters the era of multi-laser printing, with dozens or even hundreds of lasers, the time it takes to print a single laser pattern is greatly reduced, and the proportion of powder spreading time in the entire working time has suddenly increased. Therefore, how to reduce this time is of great significance. The current conventional method for reducing powder spreading time is to use bidirectional powder spreading, which allows the powder spreading scraper to spread powder once per single pass, thus reducing the powder spreading time by nearly half. Even so, the time spent on powder spreading in printing a single part can still be as long as tens of hours. Therefore, a solution that can reduce this time is of great significance in saving printing time.

[0005] The patent application with application publication number CN119457132A provides a solution for printing while spreading powder, which can effectively save the proportion of time occupied by spreading powder, and the patent provides a formula for dividing the printing area of ​​different laser heads when multiple laser printers spread powder in one-way. In a one-way powder spreading system, the powder spreading direction is the same each time, so this formula can be used to calculate the printing area of ​​different laser print heads. However, in a device for two-way powder spreading, the powder spreading direction of each layer is different. Assuming that there are a total of N rows of laser print head arrays along the powder spreading direction, each row of print heads is numbered 1 to N in sequence. When the current layer spreads powder from 1 to N, the next layer will spread powder from N to 1. When the powder spreading direction is changed, the first row of laser heads prints the two adjacent layers above and below with a longer time interval, while the Nth row of laser heads has a shorter time interval. Therefore, if the pattern printing area allocation scheme for one-way powder spreading is used, the printing time for the 1st line and the Nth line is the same, but the 1st line requires a longer waiting time. Therefore, the printing area division scheme given in the above patent application is not suitable for two-way powder spreading. A more efficient printing area division scheme is required for two-way powder spreading. Summary of the Invention

[0006] The purpose of the present invention is to provide a multi-laser bidirectional powder-laying and printing 3D printing method to solve the problem that the time required for powder laying in the multi-laser bidirectional powder-laying 3D printing method accounts for a large proportion of the total printing time.

[0007] In order to achieve the above object, the technical solution of the present invention is as follows: The present invention relates to a 3D printing method with multiple lasers and bidirectional powder spreading and printing, which comprises the following steps: S1. Determine the direction of the current powder layer and divide the powder working chamber into sub-areas equal to the number of laser print heads, with the width of the sub-areas gradually decreasing in accordance with the direction of the current powder layer; S2. The powder spreading mechanism spreads powder in the direction of the current layer. When the powder spreading is complete for a sub-area, the printing task for that sub-area is assigned to the corresponding laser print head for printing. S3. After completing the printing task of a layer of powder, determine whether the printing task of this layer is the last printing task. If not, adjust the height of the powder working chamber and return to S1; if so, complete the entire printing.

[0008] Preferably, the specific step of dividing the powder working chamber into sub-areas equal to the number of laser printing heads in S1 is: when the powder spreading direction is from the first laser printing head to the N When the laser printing head is spreading powder, the width of each sub-area is calculated one by one according to formula (1). The calculation formula is: (1), When the powder is spread from the N A laser print head to the one When the laser printing head is spreading powder, the width of each sub-area is calculated one by one according to formula (2). The calculation formula is: (2), in, i and j is the number of the sub-area, representing the i Laser print head and j The laser print head is responsible for printing the sub-area, Di and DJ Respectively represent i Laser print head and j The width of the sub-area that the laser print head is responsible for printing, D Indicates the total width of the powder working chamber, N is the total number of laser print heads, v is the powder spreading speed, s The time required for a single row of laser heads to print the entire width D format. t 1. t j and t N Respectively represent the number 1, j 、 N The time it takes for the rows of laser heads to print their respective areas; And when N ≥ j >1 o'clock, ,when j =1, .

[0009] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: 1. The multi-laser bidirectional powder-laying and printing 3D printing method involved in the present invention is aimed at the bidirectional powder-laying scheme. For each single pass, the powder working chamber is divided into sub-areas equal to the number of laser print heads, and the width of the sub-areas gradually decreases in the direction of the powder laying this time. When the powder laying of a sub-area is completed, the printing task of the sub-area is assigned to the corresponding laser print head for printing, thereby realizing powder-laying and printing, shortening the waiting time of each laser print head, and improving printing efficiency.

[0010] 2. The multi-laser bidirectional powder-laying and printing 3D printing method involved in the present invention uses two sets of formulas to calculate the width of each sub-area respectively for two single-pass powder laying, so as to minimize the waiting time of each laser print head and maximize the printing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG1 is a schematic diagram of a multi-laser bidirectional powder-laying and printing 3D printing method according to the present invention. DETAILED DESCRIPTION

[0012] In order to further understand the content of the present invention, the present invention is described in detail with reference to the examples. The following examples are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0013] The present invention relates to a 3D printing method with multiple lasers and two-way powder spreading and printing. The method is applicable to equipment that spreads powder and prints in two-way powder spreading. The so-called two-way powder spreading means that the powder spreading mechanism spreads powder once in each stroke, and a total of two powder spreadings are performed in one round trip. The so-called powder spreading and printing means that the current printing layer is divided into a number of sub-areas equal to the number of printer heads. The sub-areas correspond to the printer heads one by one. After the powder spreading of a certain sub-area is completed, the corresponding printing laser head starts to print the corresponding sub-area. At the same time, the powder spreading mechanism continues to spread powder in the following sub-areas. Figure 1 As shown, the method specifically includes the following steps: S1. Determine the powder spreading direction of the current layer of powder and divide the powder working chamber into sub-areas equal to the number of laser print heads. The width of the sub-areas gradually decreases according to the direction of the current powder spreading. Specifically: When the powder spreading direction is from the first laser print head to the N When the laser printing head is spreading powder, the width of each sub-area is calculated one by one according to formula (1). The calculation formula is: (1), When the powder is spread from the N A laser print head to the one When the laser printing head is spreading powder, the width of each sub-area is calculated one by one according to formula (2). The calculation formula is: (2), in, i and j is the number of the sub-area, representing the i Laser print head and j The laser print head is responsible for printing the sub-area, Di and DJ Respectively represent i Laser print head and j The width of the sub-area that the laser print head is responsible for printing, D Indicates the total width of the powder working chamber, N is the total number of laser print heads, v is the powder spreading speed, s The time required for a single row of laser heads to print the entire width D format. t 1.t j and t N Respectively represent the time taken by the laser heads in rows 1, j, and N to print their respective areas; And when N ≥ j >1 o'clock, ,when j =1, .

[0014] S2. The powder-laying mechanism spreads powder in the direction of the current layer of powder. When the powder laying of a certain sub-area is completed, the printing task of the sub-area is assigned to the corresponding laser print head for printing. At this time, the powder-laying mechanism spreads powder on the next sub-area, and the laser print head assigned to the printing task starts printing, thus achieving the purpose of printing while laying powder.

[0015] S3. After completing the printing task of a layer of powder, determine whether the printing task of this layer is the last printing task. If not, adjust the height of the powder working chamber and return to S1; if so, complete the entire printing.

[0016] The present invention has been described in detail above with reference to the embodiments. However, the contents described are only preferred embodiments of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A 3D printing method with multiple lasers and bidirectional powder spreading and printing, characterized in that: It includes the following steps: S1. Determine the direction of the current powder layer and divide the powder working chamber into sub-areas equal to the number of laser print heads, with the width of the sub-areas gradually decreasing in accordance with the direction of the current powder layer; S2. The powder spreading mechanism spreads powder in the direction of the current layer. When the powder spreading is complete for a sub-area, the printing task for that sub-area is assigned to the corresponding laser print head for printing. S3. After completing the printing task of a layer of powder, determine whether the printing task of this layer is the last printing task. If not, adjust the height of the powder working chamber and return to S1; if so, complete the entire printing.

2. The multi-laser bidirectional powder-laying and printing 3D printing method according to claim 1, characterized in that: The specific steps of dividing the powder working chamber into sub-areas equal to the number of laser printing heads in S1 are: when the powder spreading direction is from the first laser printing head to the N When the laser printing head is spreading powder, the width of each sub-area is calculated one by one according to formula (1). The calculation formula is: （1）， The direction of the powder is from the N A laser print head to the one When the laser printing head is spreading powder, the width of each sub-area is calculated one by one according to formula (2). The calculation formula is: （2）， in, i and j is the number of the sub-area, representing the i Laser print head and j The laser print head is responsible for printing the sub-area, Di and DJ Respectively represent i Laser print head and j The width of the sub-area that the laser print head is responsible for printing, D Indicates the total width of the powder working chamber, N is the total number of laser print heads, v is the powder spreading speed, s The time required for a single row of laser heads to print the entire width D format. t 1. t j and t N Respectively represent the number 1, j 、 N The time it takes for the rows of laser heads to print their respective areas; And when N ≥ j >1 o'clock, ,when j =1, .

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