Arc additive manufacturing path planning method
By designing a combination of L-shaped weld beads and offset paths in arc additive manufacturing and adjusting the inflection point position, the problems of over-stacking and under-stacking in arc additive manufacturing are solved, improving the forming accuracy and quality of parts and reducing the overlap rate of composite scanning paths.
Patent Information
- Application Number
- CN202211230337.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-30
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2042-09-30
AI Technical Summary
In arc additive manufacturing, multiple adjacent inflection points distributed continuously on the same side are prone to over-packing and under-packing defects, which affect the forming accuracy and quality of parts. In addition, the high overlap rate of composite scanning paths leads to uneven printing height.
By employing the path planning method of electric arc additive manufacturing, and by designing a combination of the first L-shaped weld path, the second L-shaped weld path, and the offset path, the inflection point position and scanning direction are adjusted to ensure the flatness of the path and the overlapping effect, and to avoid over-stacking and under-stacking.
It effectively eliminates over-packing and under-packing defects caused by multiple adjacent inflection points continuously distributed on the same side, improves the flatness and mechanical properties of parts during the forming process, reduces the number of codes, and saves time and costs.
Smart Images
Figure CN115722762B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of electric arc additive manufacturing, and relates to an electric arc additive manufacturing path planning method. BACKGROUND
[0002] Wire and Arc Additive Manufacturing (WAAM) is a manufacturing technology based on traditional welding technology, which uses an electric arc or a plasma arc as a heat source to melt metal wires, and a welding robot accumulates on the surface of a substrate according to a planned path layer by layer, and produces a free-form part according to a three-dimensional model.
[0003] Compared with other additive technologies, the WAAM technology has low forming size accuracy and a large molten pool, and defects such as gaps, pores, over-accumulation and under-accumulation are easily formed at the edges and intersections of the scanning path. In recent years, domestic and foreign scholars have conducted a large amount of research on these problems in the WAAM technology, mainly by changing the scanning path algorithm and adjusting the process parameters to avoid the formation of these defects, thereby improving the forming accuracy and quality of the WAAM technology when printing structural parts.
[0004] In actual production, different scanning paths and process parameters are often selected according to the length, thickness and complexity of the cross-sectional shape of the structural part. The commonly used scanning path planning algorithms include reciprocating straight line scanning path, contour offset scanning path, partition scanning path, parting line scanning path and composite scanning path thereof, wherein the composite scanning path is a combination of two or more than two scanning path planning methods, but the overlap rate between the two scanning paths in the method is high, which leads to a high printing height in the overlap area, for example Figure 1 The same side continuous distribution of multiple adjacent inflection points and the red line area form over-accumulation, and as the printing layer height increases, when printing to a certain layer height, it will affect the arc striking. SUMMARY
[0005] In order to solve the above technical problems in the background art, the application provides an electric arc additive manufacturing path planning method for eliminating over-accumulation formed by the same side continuous distribution of multiple adjacent inflection points and ensuring the height flatness during part forming.
[0006] In order to achieve the above purpose, the application adopts the following technical solutions:
[0007] An electric arc additive manufacturing path planning method, characterized in that: the electric arc additive manufacturing path planning method comprises a path for forming at least one corner-shaped member; the path of the corner-shaped member at least comprises a first L-shaped welding path, a second L-shaped welding path and a bias path; the first L-shaped welding path is connected with the second L-shaped welding path through the bias path.
[0008] The offset path length d is 0.65-0.80 times the single-layer weld bead width W,
[0009] The offset path length d is 0.738 times the single-layer weld bead width W.
[0010] The arc additive manufacturing path generation method based on the arc additive manufacturing path planning method described above, characterized in that the method comprises the following steps:
[0011] 1) Determine the number of times N that the transverse weld of the corner-shaped member weld path needs to be turned;
[0012] 2) Determine the coordinates of the arc starting point and the first L-shaped weld path, the second L-shaped weld path, and the offset path inflection point position, and determine the direction of the initial transverse weld;
[0013] 3) The longitudinal weld is turned into a transverse weld at the inflection point B2 or C2 in step 2), and step 2) is repeated until the weld scanning and filling of the B n or C n inflection point is completed.
[0014] The above step (1) is specifically: comparing the widths W2 and W1 (W3) of the two sides of the corner-shaped member, and calculating the number of times N that the transverse weld scanning needs to be turned: N is the maximum {W2, W1 (W3)} / d integer.
[0015] The above step (2) is specifically:
[0016] When N is odd, start from the arc starting point A, generate an initial transverse weld AO along one side of the corner-shaped member, and continue to scan and fill in the reverse direction along the first L-shaped weld path after the transverse weld scanning and filling to the other side of the corner-shaped member O point position offset distance d, and the transverse weld is turned into a longitudinal weld after passing through the first inflection point B1, and the reverse scanning is continued along the second L-shaped weld path after the longitudinal weld reaches the corner-shaped member edge D point position offset distance d, and the transverse weld is turned into a longitudinal weld after passing through the second inflection point B2.
[0017] When N is even, start from the arc starting point A', generate an initial transverse weld A'O along one side of the corner-shaped member, and continue to scan and fill in the reverse direction along the first L-shaped weld path after the transverse weld scanning and filling to the other side of the corner-shaped member O point position offset distance d, and the transverse weld is turned into a longitudinal weld after passing through the first inflection point C1, and the reverse scanning is continued along the second L-shaped weld path after the longitudinal weld reaches the corner-shaped member edge D' point position offset distance d, and the transverse weld is turned into a longitudinal weld after passing through the second inflection point C2.
[0018] The position coordinates of the edge point O in the above step (2) are (x, y), the coordinates of the starting point A are (x+W2+(N-1)d, y), the coordinates of the starting point A' are (x+W2+(N-2)d, y), the coordinates of the first inflection point B1 are (x+W2+(N-1)d, y+d), the position coordinates of the second inflection point B2 are (x+W2+(N-2)d, y+2d), the coordinates of the first inflection point C1 are (x+W2+(N-2)d, y+d), the coordinates of the second inflection point C2 are (x+W2+(N-3)d, y+2d), the coordinates of the edge point D are (x+W2+(N-1)d, y+W1), and the coordinates of the edge point D' are (x+W2+(N-2)d, y+W3).
[0019] The part formed based on the arc additive manufacturing path planning.
[0020] The advantages of the present application are:
[0021] (1) According to the technical characteristics of the arc additive manufacturing of the curved or corner structure, the present application changes the distribution of the inflection point position, avoids the continuous distribution of multiple adjacent inflection points on the same side, and avoids the continuous over-accumulation or under-accumulation defects on the same side, thereby ensuring the flatness of the entire cross-section filling in the continuous printing process, and helping to improve the overall quality and efficiency of the structure.
[0022] (2) By changing the distribution of the inflection point position, the mechanical properties of the adjacent inflection point path and the outer contour lap are also avoided, and the gap and other defects are avoided.
[0023] (3) By changing the distribution of the inflection point position, the bias distance d2 of the adjacent inflection point path and the outer contour lap does not need to be set separately, the code quantity is reduced, and when the material changes or the welding bead height changes, the corresponding bias distance does not need to be matched, a large amount of time and cost is saved. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 is a schematic diagram of a traditional arc additive manufacturing path planning method;
[0025] Figure 2 is a schematic diagram of the arc additive manufacturing path planning method of the present application when N is an odd number;
[0026] Figure 3 is a schematic diagram of the arc additive manufacturing path planning method of the present application when N is an even number. DETAILED DESCRIPTION
[0027] The present application provides an arc additive manufacturing path planning method for eliminating the continuous distribution of multiple adjacent inflection points on the same side, which is further described in detail below in combination with the drawings and specific embodiments.
[0028] The application provides an arc additive manufacturing path planning method for eliminating same-side continuous distribution of multiple adjacent inflection points, comprising the following steps:
[0029] (1) determining the number N of times of turning of the scanning transverse weld.
[0030] As shown in Figs. Figure 2 and Figure 3 , first, the width W2, W1 (W3) of the cross-sectional shape of the meandering structure is measured, the single-layer weld width W is set, the offset distance d = 0.65-0.080W between adjacent welds is determined, and the optimal offset distance d is 0.738W; then, the widths W2 and W1 (W3) of the two sides of the meandering structure are compared, and the number N of times of turning of the transverse weld scanning is calculated: N is the maximum {W2, W1 (W3)} / d, and the integer is taken upward.
[0031] (2) determining the coordinates of the starting arc point and the inflection point position, and determining the direction of the initial transverse weld.
[0032] When N is an odd number, the coordinate of the part endpoint O point position is O(x, y), the A(x+W2+(N-1)d, y) point position is taken as the starting arc point, and the initial transverse weld direction is along the vector AO direction; after the initial transverse weld scanning filling reaches the O point offset distance d, the reverse scanning filling is continued, the transverse weld directly changes into a longitudinal weld after reaching the inflection point B1(x+W2+(N-1)d, y+d), and then the new inflection point B2(x+W2+(N-2)d, y+2d) is searched.
[0033] When N is an even number, the coordinate of the part endpoint O point position is O(x, y), the A'(x+W2+(N-2)d, y) point position is taken as the starting arc point, and the initial transverse weld direction is along the vector A'O direction; after the initial transverse weld scanning filling reaches the O point offset distance d, the reverse scanning filling is continued, the transverse weld directly changes into a longitudinal weld after reaching the inflection point C1(x+W2+(N-2)d, y+d), and then the new inflection point C2(x+W2+(N-3)d, y+2d) is searched.
[0034] (3) repeating step (2) until the weld scanning filling of the B n (C n )th inflection point is completed, wherein 1≤n≤N-1, and n is an integer.
[0035] When all the welding bead scans in the width W1 (W3) side are filled, the welding bead scans in the width W2 side are filled first by transverse welding bead scans, and then the new scan filling path is determined again according to the method of the present application.
Claims
1. An electric arc additive manufacturing path planning method, characterized by, The arc additive manufacturing path planning method comprises a path for forming at least one corner-shaped component; the path of the corner-shaped component at least comprises a first L-shaped welding path, a second L-shaped welding path and a bias path; the first L-shaped welding path is connected with the second L-shaped welding path through the bias path; The arc additive manufacturing path planning method further comprises the following steps: 1) determining the number N of times of turning of the transverse welding of the corner-shaped component welding path; 2) determining the coordinates of the starting point and the corner points of the first L-shaped welding path, the second L-shaped welding path and the bias path, and determining the direction of the initial transverse welding; the length d of the bias path is 0.65-0.80 times the single-layer welding width W; 3) The longitudinal weld bead transitions to a transverse weld bead at the inflection point B2 or C2 in step 2) and step 2) is repeated until the weld bead scan fill is complete at the B n or C n inflection point.
2. The arc additive manufacturing path planning method of claim 1, wherein, The step 1) is specifically: comparing the widths W2 and W1 or W3 of the two sides of the corner-shaped component, thereby calculating the number N of times of turning of the transverse welding scanning, wherein the N is the upward integer of max { W2, W1 (W3)} / d.
3. The electric arc additive manufacturing path planning method of claim 2, wherein, The step 2) is specifically: When the N in the step 1) is odd, starting from the starting point A, an initial transverse welding AO is generated along one side of the corner-shaped component, the transverse welding scanning fills to the other side of the corner-shaped component, and then continues to scan and fill in the reverse direction along the first L-shaped welding path by a bias distance d, and the transverse welding changes into longitudinal welding after passing through the first corner point B1, and when reaching the edge point D of the corner-shaped component, the reverse scanning along the second L-shaped welding path is continued by a bias distance d, and the longitudinal welding changes into transverse welding after passing through the second corner point B2; When the N in the step 1) is even, starting from the starting point A', an initial transverse welding A'O is generated along one side of the corner-shaped component, the transverse welding scanning fills to the other side of the corner-shaped component, and then continues to scan and fill in the reverse direction along the first L-shaped welding path by a bias distance d, and the transverse welding changes into longitudinal welding after passing through the first corner point C1, and when reaching the edge point D' of the corner-shaped component, the reverse scanning along the second L-shaped welding path is continued by a bias distance d, and the longitudinal welding changes into transverse welding after passing through the second corner point C2.
4. The electric arc additive manufacturing path planning method of claim 3, wherein, The coordinates of the edge point O in the step 2) are (x, y), the coordinates of the starting point A are (x+W2+ (N-1) d, y), the coordinates of the starting point A' are (x+W2+ (N-2) d, y), the coordinates of the first corner point B1 are (x+W2+ (N-1) d, y+d), the coordinates of the second corner point B2 are (x+W2+ (N-2) d, y+2d), the coordinates of the first corner point C1 are (x+W2+ (N-2) d, y+d), the coordinates of the second corner point C2 are (x+W2+ (N-3) d, y+2d), the coordinates of the edge point D are (x+W2+ (N-1) d, y+W1), and the coordinates of the edge point D' are (x+W2+ (N-2) d, y+W3).
5. A part formed by the arc additive manufacturing path planning method according to any one of claims 1-4.
Citation Information
Patent Citations
3D printing path planning method for complex thin-walled structure object based on reinforcement learning
CN108995220A