Method for multi-axis linkage single-pass printing of uniform variable-width welding bead

Abstract

The method is applied to additive equipment or welding equipment, the additive equipment or welding equipment comprises a wire feeding mechanism, a heat source and a printing head, the wire feeding mechanism is used for conveying wires, the heat source melts the wires into molten drops, and the printing head walks along a planned path to deposit the molten drops into the welding bead. Through linkage of the wire feeding speed, the printing speed and heat source energy, single-pass printing of a variable-width welding pass can be achieved.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, specifically to a method for multi-axis linkage single-pass printing of uniform variable-width weld beads, wherein the multi-axis includes wire feed speed, heat source energy, and printing speed, etc. Background Technology

[0002] Additive manufacturing technology is a bottom-up, layer-by-layer digital manufacturing technology that builds up lines, surfaces, and volumes.

[0003] In existing additive manufacturing technologies, wire feeding speed, heat source energy, and printing speed are basically controlled independently and there is no direct coupling relationship between them. The printing method of the "line" is basically a single-pass printing with uniform width or height, and multi-pass printing is achieved by overlapping multiple single-pass welds.

[0004] In existing technologies, there are generally two methods for printing variable width weld beads. One method is to achieve variable width printing by varying the amplitude of the print head oscillation, such as... Figure 4 As shown, the second method is to achieve variable width printing through multiple printing passes, such as... Figure 5 As shown, the third method achieves one-time printing by using single-pass printing.

[0005] Single-pass printing is simpler and faster, but single-pass printing of weld beads with varying widths and / or heights in a single step requires the coupling and linkage of multiple variables such as wire feed speed, heat source energy, and printing speed to avoid problems such as uneven weld bead width or height or weld bead collapse on both sides. Existing technology CN106424726B provides a method for laser forming uniformly widened parts, offering a single-pass printing method. This invention belongs to the field of laser cladding and 3D forming. This method for laser forming uniformly widened parts employs layering and setting single-pass path planning for each layer. Each cladding layer is segmented, and the spot diameter and reference defocusing amount of each segment are determined based on the width of the cladding layer. During the forming process, the difference between the actual stacking height and the ideal stacking height of each segment in each layer is measured and calculated. The scanning speed of the next cladding layer is then adjusted through calculation, thereby achieving closed-loop control of the cladding layer width.

[0006] The existing technology CN106424726B achieves closed-loop control of the cladding layer width by "determining the spot diameter and reference defocus amount of the small segment, measuring and calculating the difference between the actual stacking height and the ideal stacking height of each segment in each layer during the forming process, and correcting the scanning speed of the next cladding layer by calculation". However, this method has limitations and can only be applied in the field of laser additive manufacturing technology. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention proposes a multi-axis linkage printing method. The multi-axis includes wire feeding speed, heat source energy, and printing speed. By real-time linkage of wire feeding speed, printing speed, and heat source energy, heat source energy input under different wire feeding speeds and printing speeds can be realized, ultimately achieving single-pass printing of weld beads of different widths.

[0008] A method for multi-axis linkage single-pass printing of uniform variable-width weld beads, wherein the multi-axis includes wire feed speed, printing speed, and heat source energy, the method is as follows: The current position of the print head is obtained, and the linkage relationship between the wire feed speed, printing speed, weld bead height, and heat source energy is:

[0009]

[0010] Q = V w ×△t×D 2 π / 4×(T2-T1)×C

[0011] Among them, V w V represents the wire feeding speed. p Indicates printing speed, H represents weld bead height, and d represents printing speed. 始 d represents the width at the beginning of the weld bead width change. 末 This indicates the width at the end of the weld bead width variation, where D represents the wire diameter and L represents the weld bead width variation. 变宽度 Indicates the length of the variable width weld bead, (x 始 y 始 ) represents the coordinate of the starting point of the weld width change; Q represents the heat source energy; Δt represents the unit time; C represents the heat capacity of the wire; T2 represents the molten pool temperature; and T1 represents the base material temperature.

[0012] Furthermore, the 3D≥d 始 ≥1.3D, 3D≥d 末 ≥1.3D.

[0013] Furthermore, the system includes a filament feeding mechanism, a print head, and a heat source, wherein the filament feeding speed, printing speed, and heat source energy are all adjustable and controlled by an industrial control computer.

[0014] Furthermore, the heat source is a laser heat source, including one or more independently controllable lasers.

[0015] Beneficial technical effects: This invention enables the printing of single-pass welds with varying widths and / or heights by instantaneously linking wire feeding speed, heat source energy, and printing speed. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a single-pass printing of a uniformly variable width weld bead according to the present invention.

[0017] Figure 2This invention is a single-pass printing method. Figure 1 A schematic diagram showing the linkage between the filament feed speed, printing speed, and the current position of the print head.

[0018] Figure 3 This invention is a single-pass printing method. Figure 1 A schematic diagram showing the linkage between wire feeding speed and heat source energy.

[0019] Figure 4 This is a schematic diagram of existing technology for printing variable width weld beads using a swing path.

[0020] Figure 5 This is a schematic diagram of existing technology for printing variable width weld beads using multiple paths.

[0021] In the diagram: 1 - weld bead; 2 - weld bead centerline. Detailed Implementation

[0022] The technical solution of the present invention will now be clearly and completely described in conjunction with the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0023] A method for multi-axis linkage single-pass printing of uniform variable-width weld beads is disclosed. This method is applied to additive manufacturing equipment or welding equipment, which includes a wire feeding mechanism, a heat source, and a print head. The wire feeding mechanism transports wire, the heat source melts the wire into droplets, and the print head travels along a planned path to deposit the droplets as weld beads. The wire feeding mechanism is driven by a servo motor, and the forward and reverse rotation of the servo motor enables wire feeding and drawing. The wire feeding speed of the wire feeding mechanism is adjustable. The heat source energy is adjustable and can be an electric arc, plasma arc, laser, or electron beam, etc. When the heat source is a laser, it includes one or more lasers, the power of which can be independently controlled. The print head is connected to a multi-axis robot, and the printing speed of the print head is adjustable.

[0024] The method of this invention, through the linkage of wire feeding speed, printing speed, and heat source energy, can be used to print uniformly variable width weld beads in a single pass.

[0025] The method of this invention is used for single-pass printing of uniformly variable width weld beads. It is based on the position information of the print head, the width and height information of the weld bead, and is achieved by controlling the instantaneous linkage of wire feeding speed, printing speed and heat source energy.

[0026] The method of the present invention for printing uniformly variable width weld beads in a single pass includes the following steps:

[0027] S1: The 3D model of the uniformly variable width part is sliced ​​into layers according to a certain height. The upper and lower surfaces of each slice are horizontal, and the width of each slice varies uniformly, such as widening or narrowing along a fixed slope, or uniformly varying in the shape of a circle or ellipse.

[0028] S2: The uniform variable width weld bead is printed using a single-pass printing method.

[0029] Example 1: When the uniformly variable width part described in S1 widens or narrows along a fixed slope, such as Figure 1 As shown, the printing method is as follows: obtain the real-time position (x, y, z) of the industrial computer's print head; then, when printing a certain layer slice, i.e., with a fixed z value, the linkage relationship between wire feed speed, printing speed, weld height, and heat source energy is as follows:

[0030]

[0031] Q = V w ×△t×D 2 π / 4×(T2-T1)×C

[0032] Among them, V w V represents the wire feeding speed. p Indicates printing speed, H represents the layer height of this slice, and d represents the printing speed. 始 This represents the width at the beginning of the weld bead width change, 3D≥d 始 ≥1.3D, d 末 This represents the width at the end of the weld bead width variation, 3D≥d 末 ≥1.3D, where D represents the wire diameter, which ranges from 0.3 to 2.0 mm.

[0033] L 变宽度 Indicates the length of the variable width weld bead, (x 始 y 始 ) represents the coordinate of the starting point of the weld width change; Q represents the heat source energy; Δt represents the unit time; C represents the heat capacity of the wire; T2 represents the final temperature of the wire, i.e. the molten pool temperature; and T1 represents the temperature of the base material.

[0034] This embodiment 1 is specifically referenced. Figure 1-3 ,like Figure 1 The diagram shows a single-pass printing schematic of a uniformly variable width weld bead. The printing method is as follows:

[0035] Weld bead L that widens uniformly from narrow 变宽 The relationship between wire feed speed, printing speed, weld height, and heat source energy is as follows:

[0036]

[0037] Q = V w ×△t×D2 π / 4×(T2-T1)×C

[0038] Among them, V w V represents the wire feeding speed. p The value represents the printing speed, H represents the weld bead height, d1 represents the width at the beginning of the weld bead width change (3D ≥ d1 ≥ 1.3D), d2 represents the width at the end of the weld bead width change (3D ≥ d2 ≥ 1.3D, d2 > d1), D represents the wire diameter, and L... 变宽 Indicates the length of the variable width weld bead.

[0039] (x0, y0) represents the coordinates of the starting point of the weld width change; Q represents the heat source energy; Δt represents the unit time; C represents the heat capacity of the wire; T2 represents the final temperature of the wire, i.e. the molten pool temperature; and T1 represents the temperature of the base material.

[0040] Weld bead L that narrows uniformly from wide 变窄 The relationship between wire feed speed, printing speed, weld height, and heat source energy is as follows:

[0041]

[0042] Q = V w ×△t×D 2 π / 4×(T2-T1)×C

[0043] Among them, V w V represents the wire feeding speed. p The values ​​represent printing speed, H represents weld bead height, d2 represents the width at the beginning of the weld bead width change (3D ≥ d2 ≥ 1.3D), d3 represents the width at the end of the weld bead width change (3D ≥ d3 ≥ 1.3D, d2 > d3), D represents wire diameter, and L... 变窄 Indicates the length of the variable width weld bead.

[0044] (x1, y1) represents the coordinates of the starting point of the weld width change; Q represents the heat source energy; Δt represents the wire feeding time; C represents the heat capacity of the wire; T2 represents the final temperature of the wire, i.e. the molten pool temperature; and T1 represents the temperature of the base material.

[0045] Print as Figure 1 The diagram showing the linkage between wire feed speed, printing speed, and current print head position for a uniformly variable width and equal height weld bead is as follows: Figure 2 and 3 As shown. During the single-pass printing of this weld bead, the weld bead height H is kept constant, and the printing speed V is... p Given constant d1, d2, d3, and L 变宽 L 变窄 (x0, y0) and (x1, y1) are given by Figure 2As can be seen, during the linkage process, the printing speed remains constant as the print head's current position changes, while the filament feed speed changes linearly with the print head's current position. Figure 3 It can be seen that the heat source energy changes linearly with the wire feeding speed.

[0046] The method of the present invention is particularly applicable to laser wire feeding additive manufacturing equipment or welding equipment. When the laser is multiple independently controllable lasers, the power output of each laser can be independently controlled according to the total heat source energy.

[0047] To those skilled in the art, the above embodiments are exemplary and non-limiting. The scope of protection of the present invention is not limited by the above embodiments, and no reference numerals in the claims should be construed as limiting the scope of protection of the claims.

Claims

1. A method for multi-axis linkage single-pass printing of uniform variable-width weld beads, characterized in that: The multi-axis system includes wire feed speed, printing speed, and heat source energy. The method involves obtaining the current position of the print head, and then determining the linkage relationship between the wire feed speed, printing speed, weld height, and heat source energy: Q=V w ×△t×D 2 π / 4×(T2-T1)×C Among them, V w V represents the wire feeding speed. p Indicates printing speed, H represents weld bead height, and d represents printing speed. 始 d represents the width at the beginning of the weld bead width change. 末 This indicates the width at the end of the weld bead width variation, where D represents the wire diameter and L represents the weld bead width variation. 变宽度 Indicates the length of the variable width weld bead, (x 始 y 始 ) represents the coordinate of the starting point of the weld width change; Q represents the heat source energy; Δt represents the unit time; C represents the heat capacity of the wire; T2 represents the molten pool temperature; and T1 represents the base material temperature.

2. The method for multi-axis linkage single-pass printing of uniform variable width weld beads according to claim 1, characterized in that: The 3D≥d 始 ≥1.3D, 3D≥d 末 ≥1.3D.

3. The apparatus using the method of claim 1, characterized in that: It includes a filament feeding mechanism, a print head, and a heat source, wherein the filament feeding speed, printing speed, and heat source energy are all adjustable and controlled by an industrial control computer.

4. The device according to claim 3, characterized in that: The heat source is a laser heat source, including one or more independently controllable lasers.

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