Laser processing method

Abstract

The present invention discloses a laser processing method, comprising the following steps: forming a strip region of a set width; generating a laser processing trajectory in the strip region. The laser processing trajectory includes non-overlapping line segments and / or line segments that intersect to form points; and performing laser processing in the strip region according to the laser processing trajectory. The method achieves the effect of reducing the laser energy density by increasing the irradiation area of ​​the laser spot and reducing the residence time of the laser spot at a certain point on the plane, thereby achieving a more uniform energy output and reducing the occurrence of manufacturing defects such as splashing caused by local energy imbalance.

Description

Technical Field

[0001] The invention relates to the technical field of laser processing, and in particular to a laser processing method. Background Art

[0002] High-power lasers, as heat sources for metal melting processing, have been widely used in various industrial fields. Compared with traditional electric energy processing and gas combustion methods, laser processing has outstanding features such as high control accuracy, high energy density, simple system and easy operation.

[0003] The energy distribution of the laser spot is usually a Gaussian distribution, that is, the energy at the center of the spot is the highest, and the energy gradually decreases from the center of the spot to the edge. Gaussian distribution can make the center of the beam absorb heat energy quickly, which can make the metal melt more quickly in high-power processing situations, and the liquid metal pool formed by the melting of the material will also be deeper. However, since the thermal conductivity K coefficient of metals has an upper limit, when the heat accumulates locally and exceeds the upper limit of metal conduction, the liquid metal will quickly vaporize and evaporate. This reaction will form a gas cavity inside the molten pool, and splashes of liquid metal droplets will appear outside.

[0004] The output of energy is divided into two dimensions: time and space. With P representing power and T representing time, the laser output energy Q = P*T. The energy density Z is expressed as the energy output of the laser per unit area S of the processed object, Z = Q / S. Combining the two formulas, we get Z = P*T / S. The magnitude of the energy density is related to the thermal energy absorption of the metal. When the metal absorbs too much thermal energy, it will cause gas cavities to form inside the molten pool and splashing of liquid metal droplets outside. Therefore, in order to reduce local heat imbalance during laser processing, the laser trajectory needs to be more evenly distributed and have a lower energy density. Referring to the above formula (Z = P*T / S), if you want to reduce the energy density, you need to increase S (that is, expand the irradiation range of the light spot) or reduce T (reduce the residence time of the light spot at a certain point on the plane). Summary of the invention

[0005] In order to overcome the problem of local heat imbalance during the above-mentioned laser processing, the purpose of the present invention is to provide a laser processing method, which achieves the purpose of reducing energy density by increasing S (i.e., expanding the irradiation range of the light spot) and reducing T (reducing the residence time of the light spot at a certain point on the plane), thereby solving the problem of local heat imbalance during laser processing.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is: a laser processing method, comprising the following steps:

[0007] Form a strip area of ​​set width;

[0008] generating a laser processing trajectory in the strip-shaped area, wherein the laser processing trajectory includes non-overlapping line segments and / or line segments intersecting into points;

[0009] Laser processing is performed in the strip-shaped area according to the laser processing trajectory.

[0010] This processing method increases S by forming a strip area of ​​set width, that is, expanding the irradiation range of the light spot; at the same time, since the laser processing trajectory generated in the strip area includes non-overlapping line segments and / or line segments that intersect to form points, T is reduced, that is, the residence time of the light spot at a certain point on the plane is reduced, thereby achieving the purpose of reducing the energy density.

[0011] In some embodiments, the step of forming a strip region of a set width includes:

[0012] forming a first reference line;

[0013] Decomposing the first reference line into a plurality of straight line segments;

[0014] Taking the decomposed multiple straight line segments as a reference, each line segment is translated inwardly along the vertical direction of the line segment by a set width to form a second reference line, and the first reference line and the second reference line enclose a strip area of ​​the set width.

[0015] This method decomposes the first baseline into the plurality of straight line segments and translates them to form the strip-shaped area. The method is simple and easy to implement without complicated calculations. The size of the strip-shaped area is controlled by controlling the translation distance of the line segments, thereby achieving the effect of controlling the energy density.

[0016] In some embodiments, the step of forming a strip region of a set width includes:

[0017] forming a first reference line;

[0018] Decomposing the first reference line into a plurality of curve segments with gentle curvature;

[0019] The entire curve is shifted by translating the curve control points according to the Bezier curve to obtain a second reference line, wherein the first reference line and the second reference line enclose a strip area of ​​the set width.

[0020] This method can obtain the second baseline to form the strip area by translating the control points of the curve segment decomposed from the first baseline. The operation steps are relatively simple, and the size of the strip area can be controlled by controlling the translation distance of the control points, thereby achieving the effect of controlling the energy density.

[0021] In some embodiments, the step of forming a strip region of a set width includes:

[0022] forming a first reference line, wherein the first reference line is a circle;

[0023] Randomly select the first vertex on the first baseline;

[0024] According to the first vertex, multiple vertices are taken on the first reference line using the same set angle interval;

[0025] Connecting the plurality of vertices to form an area where line segments intersect each other;

[0026] The contour of the mutually intersecting areas formed by a circle concentric with the first reference line is the second reference line;

[0027] The first reference line and the second reference line form the band-shaped area.

[0028] This method generates a second reference line and forms a strip-shaped area by taking vertices and connecting them. The operation method is simple and easy, has a certain regularity, and while forming the strip-shaped area, the required laser processing trajectory can be obtained, simplifying the overall steps.

[0029] In some implementations, the central angles formed by two adjacent vertices and the center of the circle are taken in sequence as the set angle.

[0030] This method can make the strip-shaped areas have equal width.

[0031] In some embodiments, the set angle is an angle calculated based on a desired laser processing track overlap and a formula.

[0032] This method calculates the required setting angle according to the overlap required for laser track processing, so that the size of the strip area is controlled by the setting angle, thereby achieving the effect of controlling the energy density.

[0033] In some embodiments, the strip-shaped area has the first reference line and the second reference line; the first reference line and the second reference line are closed-loop curves respectively; and the strip-shaped area is a body of equal width.

[0034] The equal-width body can make the laser processing trajectory have a certain regularity, simplify the difficulty of planning the laser processing trajectory, and thus achieve a more uniform distribution of the laser processing trajectory. The uniform laser processing trajectory can reduce the residence time of the light spot at a certain point on the plane, thereby reducing the energy density of the laser on the processed object and solving the problem of local heat imbalance.

[0035] In some embodiments, the first reference line is any one of the following: a circle, an ellipse, or any smooth boundary curve described by a Bezier curve equation or a spline curve equation.

[0036] The smooth boundary curve can make the laser processing trajectory more regular, thereby making the laser processing trajectory more evenly distributed, achieving the purpose of more even energy output and solving the problem of local heat imbalance.

[0037] In some embodiments, generating a laser processing track in the strip region comprises the following steps:

[0038] The strip area includes the first reference line and the second reference line, and the first reference line and the second reference line are divided at a certain step length in the strip area;

[0039] The split points are alternately connected to form a reciprocating zigzag laser processing trajectory.

[0040] In this method, the laser processing trajectory uses non-overlapping line segments, and the laser trajectory processing is performed by dividing the first baseline and the second baseline in the strip area with a certain step length. While having a certain regularity, it avoids the laser trajectory from staying at a certain point, thereby achieving the effect of reducing energy density. In addition, the laser processing trajectory used in this method is relatively simple and easy to implement.

[0041] In some embodiments, generating a laser processing track in the strip region comprises the following steps:

[0042] A circle moves along the centerline trajectory of the strip-shaped area and simultaneously rotates about its own center to obtain a spiral trajectory.

[0043] In this method, the laser processing trajectory uses line segments that intersect to form points, and a spiral line is used to perform laser trajectory processing in the strip area. The spiral line has fewer intersection points, which can effectively reduce the residence time of the laser processing trajectory at a certain point, thereby achieving the effect of reducing energy density.

[0044] In some embodiments, generating a laser processing track in the strip region comprises the following steps:

[0045] The strip area includes the first reference line and the second reference line, the first reference line is circular, vertices are taken on the first reference line using the same set angle interval, and the vertices are connected to form a polygonal scanning trajectory.

[0046] In this method, the laser processing trajectory uses line segments that intersect to form points. This method can obtain the required laser processing trajectory while expanding the strip area, simplifying the overall steps. In addition, the processing trajectory of this method has regularity, which can make the laser trajectory evenly distributed in the strip area, reducing local heat imbalance during laser processing.

[0047] In some implementations, the angle of the central angle formed by two adjacent vertices and the center of the circle is the set angle.

[0048] This method can make the laser processing track evenly and regularly distributed within the strip area, thereby solving the problem of local heat imbalance.

[0049] In some embodiments, the set angle is an angle calculated based on a desired laser processing track overlap and a formula.

[0050] This method calculates the required setting angle according to the overlap required for processing and a formula, thereby controlling the density of the laser processing track.

[0051] In some embodiments, generating a laser processing track in the strip region comprises the following steps:

[0052] The strip-shaped area includes the first reference line and the second reference line, the first reference line and the second reference line are respectively elliptical, and a plurality of mutually surrounding or intersecting elliptical laser processing tracks are formed in the strip-shaped area.

[0053] In this method, the laser processing trajectory uses line segments that intersect into points or non-overlapping line segments to reduce the irradiation time of the laser spot at a certain point; the laser processing trajectory is evenly and regularly distributed inside the strip area, and the laser processing trajectory can be set with reference to the first reference line and the second reference line; at the same time, the number of elliptical circles of the laser processing trajectory in the strip area can be controlled to control the energy output of the laser, thereby achieving the effect of controlling the laser energy density.

[0054] The beneficial effect of the present invention is that the energy density of the laser is reduced by increasing the irradiation range of the laser spot and reducing the irradiation time of the laser at a certain point on the plane, and the laser trajectory has a certain regularity and is evenly distributed inside the strip area, thereby achieving more uniform energy output and reducing the occurrence of manufacturing defects such as spattering caused by local energy imbalance. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A schematic diagram of a laser processing method according to an embodiment of the present invention;

[0056] Figure 2 It is a schematic diagram of the decomposition of the first reference line in the line segment offset method in the laser processing method according to one embodiment of the present invention;

[0057] Figure 3 Schematic diagram for chord height definition;

[0058] Figure 4A schematic diagram of a strip-shaped area formed by offsetting line segments in a line segment offset method in a laser processing method according to an embodiment of the present invention;

[0059] Figure 5 This is a schematic diagram of forming a band-shaped area using a curve fitting method in a laser processing method according to an embodiment of the present invention:

[0060] Figure 6 Schematic diagram of Bezier curve and its control points;

[0061] Figure 7 A schematic diagram of forming a strip-shaped area by a polygon scanning method in a laser processing method according to an embodiment of the present invention;

[0062] Figure 8 A schematic diagram of forming a laser processing trajectory using a broken line method in a laser processing method according to an embodiment of the present invention;

[0063] Fig. 9 A schematic diagram of forming a spiral line in a spiral line method in a laser processing method according to an embodiment of the present invention;

[0064] Fig.10 A schematic diagram of forming a laser processing trajectory in a spiral line method in a laser processing method according to an embodiment of the present invention;

[0065] Fig.11 A schematic diagram of a laser processing trajectory formed by a polygon scanning method in a laser processing method according to an embodiment of the present invention;

[0066] FIG. 12( a ) is a schematic diagram of forming a laser processing trajectory by an equally divided contour line method in a laser processing method according to an embodiment of the present invention;

[0067] FIG12( b ) is a schematic diagram of a laser processing trajectory formed by a track-changing filling line segment method in a laser processing method according to an embodiment of the present invention;

[0068] In the figure: 1 laser processing trajectory, 2 first baseline, 3 second baseline, 4 centerline trajectory, 5 converted line segment, 6 chord height, 7 strip area, 8 endpoint connection, 9 completion to form a circle, 10 division point on the first baseline, 11 division point on the second baseline, 12 Bezier curve, 13 split line, a control point one, b control point two, c control point three, d control point four, D starting point, E ending point, R radius of the spiral circle, L spiral step distance, F vertex, G vertex, H vertex, O center of the circle, I endpoint one, J endpoint two. DETAILED DESCRIPTION

[0069] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0070] refer to Figure 1 , the embodiment of the present application provides a laser processing method, comprising the following steps:

[0071] S1000: forming a strip region 7 of a set width.

[0072] By forming a strip area 7 of a set width, for example, the laser processing track 1 is expanded from the original single line segment to the strip area 7 of a set width of 1 mm, thereby achieving the purpose of increasing S, and increasing S means expanding the irradiation range of the laser spot. According to the formula Z = P*T / S, increasing S can effectively reduce the energy density Z and reduce the occurrence of the phenomenon of local heat imbalance.

[0073] In the prior art, the laser processing trajectory is generally composed of a single line segment. When processing metal with this laser trajectory, local uneven heat is prone to occur, resulting in the formation of gas cavities inside the molten pool and splashing of liquid metal droplets outside.

[0074] Furthermore, by expanding the laser processing trajectory 1 from a single line segment to a strip-shaped area 7, the laser processing trajectory can be more evenly distributed, and the irradiation time at a certain point on the plane can be reduced by the laser trajectory, thereby reducing the energy density of the laser and achieving a more uniform energy output.

[0075] S2000: Generate a laser processing trajectory 1 in the strip area 7, the laser processing trajectory 1 including non-overlapping line segments and / or line segments intersecting into points.

[0076] Non-overlapping line segments are two or more line segments without overlapping parts; line segments that intersect into a point are two or more line segments with a common point; non-overlapping line segments and line segments that intersect into a point have both non-overlapping trajectory methods and intersecting trajectory methods. Using this laser processing trajectory 1 can achieve the purpose of reducing T, which means reducing the time the light spot stays at a certain point on the plane. According to the formula Z = P*T / S, reducing T can reduce the irradiation time of the same local area, thereby solving the problem of uneven heat.

[0077] S3000: Perform laser processing in the band-shaped area 7 according to the laser processing trajectory 1.

[0078] Laser processing performed by this method can effectively reduce energy density and local heat imbalance, which will greatly improve the performance of traditional swing trajectories.

[0079] Next, a method of forming the band-shaped region 7 with a predetermined width will be described by way of example.

[0080] In some implementations, the method for forming a strip region 7 of a set width in step S1000 is a line segment offset method.

[0081] The steps of forming the strip area 7 by the line segment offset method include:

[0082] S1010: forming a first reference line 2;

[0083] See attached Figure 2 As shown, the trajectory that the laser originally needs to process is a single line segment as the first reference line 2.

[0084] S1020: Decomposing the first reference line 2 into a plurality of straight line segments;

[0085] The first reference line 2 is decomposed into a series of straight line segments to obtain the transformed line segments 5, such as Figure 2 As shown. Figure 3 As shown, the decomposed first reference line 2 can be used to determine the error between the line segment and the curve chord height 6. For example, according to the line segment decomposition with a chord height 6 of 0.1 mm, there is an error between the continuous line segment and the original curve, but the maximum does not exceed 0.1 mm, that is, the chord height 6 does not exceed 0.1 mm.

[0086] Attached Figure 3 A schematic diagram showing the definition of the chord height 6 is shown: the line segment from the intersection of the straight line passing through the midpoint of the chord and perpendicular to the chord with the circle to the foot of the perpendicular is called the chord height 6. In combination with the above steps, according to the arc composed of the part of the first reference line 2 that needs to be decomposed, i.e., endpoint one I and endpoint two J, it is completed into a complete circle to obtain a circle 9 formed by completing the part of the first reference line 2 that needs to be decomposed, and the two endpoints of the curve of the part that needs to be decomposed according to the first reference line 2 are connected to form an endpoint connection line 8, and the endpoint connection line 8 is translated. According to the chord height 6 not exceeding 0.1 mm, an error judgment is made to obtain multiple converted line segments 5.

[0087] S1030: Taking the decomposed and transformed line segments 5 as a reference, each line segment is translated inwardly along the vertical direction of the line segment by a set width to form a second reference line 3, and the first reference line 2 and the second reference line 3 enclose a strip area 7 of the set width.

[0088] See attached Figure 4 As shown, taking multiple transformed line segments 5 as the reference, each line segment is translated inwardly in the vertical direction of the transformed line segment 5, and the moving distance is the set width, 1mm is taken as an example here. Since each line segment is translated inwardly in the vertical direction of the line segment, this process actually reduces the area enclosed by the transformed line segment 5. The newly generated fill line is obtained by translating the original line segment inward, so the area of ​​the enclosed area will be smaller than the area of ​​the original transformed line segment 5, and adjacent newly generated fill lines will have intersections. If the first reference line 2 is closed, the newly generated fill will first form a closed offset line segment, that is, the second reference line 3, and the first reference line 2 and the second reference line 3 will enclose a strip area 7 of a set width.

[0089] In some implementations, the method for forming a strip region 7 of a set width in step S1000 is a curve fitting method.

[0090] The steps of forming the band region 7 by the curve fitting method include:

[0091] S1040: forming a first reference line 2;

[0092] In the curve fitting method, the first reference line 2 is the original processing trajectory of the laser.

[0093] S1050: Decomposing the first reference line 2 into a plurality of curve segments with gentle curvature;

[0094] The entire curve is shifted by translating the control points of the Bezier curve to obtain a second reference line 3. The first reference line 2 and the second reference line 3 enclose a strip area 7 of a set width.

[0095] See attached Figure 5 As shown, this embodiment is a curve fitting method in a method for forming a strip area 7 of a set width. The curve fitting method is to divide the trajectory that the laser originally needs to process from a single line segment as the first reference line 2 into multiple segments according to the splitting line 13. The curvature is used to represent the bending degree of the line segment. A gentle curvature indicates that the bending degree of the line segment is small. The basis for splitting the original curve is that the curvature of each line segment after the split is sufficiently gentle. The Bezier curve 12 is still the Bezier curve 12 after splitting. Only the curve control point can be translated to achieve the offset of the entire curve to obtain the second reference line 3. The first reference line 2 and the second reference line 3 surround a strip area 7 of a set width.

[0096] Attached Figure 6 A schematic diagram of a Bezier curve 12 and its control points is shown. The Bezier curve 12 can be determined by four control points: control point 1 a, control point 2 b, control point 3 c, and control point 4 d. Therefore, when translating the Bezier curve 12, the four control points of the Bezier curve 12 can be translated to obtain the entire translated curve.

[0097] In some implementations, the method of forming a strip region 7 of a set width in step S1000 is a polygon scanning method.

[0098] The steps of forming the strip area 7 by the polygon scanning method include:

[0099] S1060: forming a first reference line 2, the first reference line 2 is circular, and a polygon scanning method may be used.

[0100] S1070: Randomly select the first vertex on the first reference line 2: this vertex is used as a reference for subsequent vertices.

[0101] S1080: Take multiple vertices on the first reference line 2 in sequence:

[0102] See attached Figure 7 As shown, a vertex F is randomly selected on the first reference line 2, and according to the first vertex F, the center O and vertex F are connected, and the central angle ∠FOG formed by vertex F, the second vertex G and the center O is the set angle, based on which the second vertex G can be obtained; according to the second vertex G, the center O and vertex F are connected, and the central angle GOH formed by the third vertex H of vertex G and the center O is the set angle, based on which the third vertex H can be obtained; and so on, the subsequent vertices are obtained.

[0103] S1090: Connect the vertices to form an area where line segments intersect each other.

[0104] See attached Figure 7 , and combined with the attached Fig.11 As shown, the area where the line segments intersect each other is the strip area 7;

[0105] The contour of a circle concentric with the first reference line 2 formed by the mutually intersecting areas is the second reference line 3 .

[0106] The central angle formed by two adjacent vertices and the center of the circle is taken as the set angle.

[0107] The set angle is the angle calculated based on the overlap of the target laser processing trajectory 1 and the formula: for example, if the overlap is expected to be 8%, it is necessary to reduce 360°*0.08=28.8°, then the polygon cycle angle is 360°-28.8°=331.2°. Taking the inscribed pentagon as an example, the corresponding polygon vertex angle becomes 331.2°÷5=66.24°.

[0108] A strip region 7 is obtained by the above three methods. The strip region 7 has a first reference line 2 and a second reference line 3. The first reference line 2 and the second reference line 3 ensure that the enclosed strip region 7 is of equal width and has approximately equal width in the tangent direction.

[0109] The first reference line 2 is any of the following: a circle, an ellipse, or any smooth boundary curve described by a Bezier curve equation or a spline curve equation. Figure 5 The surface with smooth boundary is described by the Bezier curve equation; Figure 7 , a circular boundary curve is shown; and FIG. 12 shows an elliptical boundary curve.

[0110] In some embodiments, the method of generating the laser processing trajectory 1 in the strip-shaped area 7 in step S2000 may be a broken line method.

[0111] The steps of forming a laser processing trajectory 1 by the broken line method include:

[0112] S2010: The strip region 7 includes the first reference line 2 and the second reference line 3. Inside the strip region 7, the first reference line 2 and the second reference line 3 of the strip region are divided with a certain step length:

[0113] See attached Figure 8 As shown, this embodiment is to generate a broken line method laser processing trajectory 1 in a laser processing trajectory 1: the strip area 7 includes a first reference line 2 and a second reference line 3, and inside the strip area 7, the first reference line 2 and the second reference line 3 of the strip area 7 are divided by a set step length to form a division point;

[0114] The step length is expressed as the length of the cutting line required between the first reference line 2 and the second reference line 3. The cutting line represents the line connecting the segmentation point 10 on the first reference line 2 and the segmentation point 11 on the second reference line 3, and the strip area 7 is cut. The step length can also represent the density of the cutting. The smaller the step length, the greater the density of the cutting line, that is, the denser the laser processing track 1 is. On the contrary, the larger the step length, the smaller the density of the cutting line, that is, the sparser the laser processing track 1 is. The theoretical value range of the step length is: the step length is greater than or equal to the distance translated when the first reference line 2 forms the second reference line 3; the step length is less than or equal to the length of the first reference line 2.

[0115] When the step length is equal to the distance translated when the first reference line 2 forms the second reference line 3, the laser processing trajectory 1 is equivalent to processing and scanning all positions of the entire strip area 7; when the step length is equal to the first reference line 2, the laser processing trajectory 1 is equivalent to processing and scanning the trajectory of the first reference line 2.

[0116] S2020: Alternately connect the division points 10 on the first reference line 2 and the division points 11 on the second reference line 3 to form a reciprocating zigzag laser processing trajectory 1.

[0117] In some embodiments, the method of generating the laser processing track 1 in the strip-shaped area 7 in step S2000 may be a spiral line method.

[0118] The steps of generating laser processing trajectory 1 by spiral line method include:

[0119] S2030: Use a circle to move along the center line trajectory of the strip area 7, and at the same time, the circle rotates around its own center to obtain a spiral trajectory.

[0120] See attached Fig. 9 As shown, this embodiment is to generate a spiral line of a spiral laser processing trajectory 1. The spiral line is formed by the superposition of the rotational motion of a circle with its own center and the linear motion. It can be realized by superposition of the parametric equation of the circle and the parametric equation of the center line trajectory 4 of the circle. Therefore, the steps of parametric modeling of the spiral laser processing trajectory 1 include:

[0121] S2031: Parametric equations of a circle:

[0122] ax=R*Cos(angle)

[0123] ay=R*Sin(angle) (1)

[0124] angle=θ*n

[0125] In formula (1), a is a constant, R is the radius of the circle, x is the horizontal coordinate, y is the vertical coordinate, and θ and n are variable parameters.

[0126] S2032: 4-parameter equation of centerline trajectory, here we take the third-order Bezier curve as an example:

[0127] bx=(1-t) 3 *x 0 +(1-t) 2 *t*x 1 +(1-t)*t 2 *x 2 +t 3 *x 3

[0128] by=(1-t) 3 *y 0 +(1-t) 2 *t*y 1 +(1-t)*t 2 *y 2 +t 3 *y 3 (2)

[0129] In formula (2), b is a constant, x is the horizontal coordinate, and y is the vertical coordinate. The third-order Bezier curve parameter equation is a displacement equation, where (x 0 ,y 0 ) and (x 3 ,y 3 ) are the endpoint coordinates of the curve starting point D and ending point E,

[0130] (x 1 ,y 1 ) and (x 2 ,y 2 ) are the coordinates of the curve control points. A Bezier curve can be determined by four control points: the starting point D, the end point E, (x 1 ,y 1 )、(x 2 ,y 2) constitute the four control points of the curve; t is the variable of the parametric equation, and its value range is [0,1]. When t changes continuously between [0,1], a series of coordinate points on the curve are obtained. When t = 0, the coordinate point is the starting point D(x 0 ,y 0 ); when t = 1, the coordinate point is the end point E(x 3 ,y 3 ).

[0131] S2033: Since the spiral line is the superposition of the motion of the circular trajectory along the centerline trajectory 4, the parametric equation of the spiral line is the superposition of the parametric equation of the circle and the parametric equation of the centerline trajectory 4;

[0132] The 4-parameter equation of the centerline trajectory is:

[0133]

[0134] In formula (3), a, b, c are constants, x is the horizontal coordinate, and y is the vertical coordinate;

[0135] When the center line is a straight line along the positive direction of the X-axis, the center line trajectory 4 parameter equation can be simplified to x = L*n, y = 0;

[0136] Therefore, the simplest form of the spiral equation can be:

[0137]

[0138] In formula (4), c is a constant, x is the horizontal coordinate, y is the vertical coordinate, R is the radius of the helical circle, n is the helical oscillation frequency, and L is the helical step distance. R, n, and L are optional parameters.

[0139] The specific setting values ​​of all optional parameters (such as the above-mentioned spiral oscillation frequency n, spiral step distance L, and spiral circle radius R) can be saved as a configuration file, and the data of the configuration file can be directly updated to the current parameters so that the value of this parameter can be referenced or used in the future when laser processing the same or similar trajectory.

[0140] The parameter equation can be changed by changing the optional parameters, that is, changing the size of the band area 7 and the density of the laser processing track 1. Changing the size of the band area 7 is to change S, and changing the density of the laser processing track 1 is to change T. Different energy density output settings can be achieved through adjustable parameters.

[0141] See attached Fig.10As shown, this embodiment is a schematic diagram of a spiral laser processing trajectory 1 in generating a laser processing trajectory 1. The laser processing trajectory 1 is evenly and regularly distributed in the strip area 7, and the laser processing trajectory 1 does not exceed the range surrounded by the first reference line 2 and the second reference line 3. The laser processing trajectory 1 used in this method is a line segment that intersects into a point, which can effectively reduce the irradiation time of the laser spot at a certain point.

[0142] In some embodiments, the method of generating the laser processing track 1 in the strip area 7 in step S2000 may be a polygon scanning method.

[0143] The steps of generating laser processing trajectory 1 by polygon scanning method include:

[0144] S2040: The strip area 7 includes the first reference line 2 and the second reference line 3, the first reference line 2 is circular, and vertices are taken on the first reference line 2 using the same set angle interval, and the vertices are connected to form a polygonal scanning trajectory.

[0145] See attached Fig.11 , and combined with FIG. 7, it is shown that the polygon scanning method in this embodiment is used to generate the laser processing trajectory 1. The polygon formation here mainly adopts two generation methods: equal side length and equal angle:

[0146] (1) Equal-side length method: divide the polygon into several vertices equally according to the length of the first reference line 2.

[0147] (2) The equal angle method is to divide the vertices of the polygon into equal parts according to the change in the circular angle of the first reference line 2.

[0148] Take the equal angle method of the polygon inscribed in a circle as an example. The angle change of a circle in one cycle is 360°, and the angle of the inscribed pentagon is 360°÷5=72°, so the set angle is 72°. Therefore, the vertices are selected according to the central angle of the two adjacent vertices being 72°, and then the adjacent vertices are connected with a straight line.

[0149] Substituting n = 0, 1, 2, 3, 4 and θ = 72° into the following formula, we can get the vertices of the pentagon:

[0150] ax=R*Cos(angle)

[0151] ay=R*Sin(angle) (5)

[0152] angle=θ*n

[0153] In formula (5), a is a constant, R is the radius of the circle, x is the horizontal coordinate, y is the vertical coordinate, n is the variable parameter of the nth vertex, and θ is the set angle.

[0154] The polygonal laser processing trajectory 1 can be obtained by connecting adjacent vertices.

[0155] In some embodiments, the central angle formed by two adjacent vertices and the center of the circle is taken as the set angle, that is, θ in formula (5) is substituted into the set angle.

[0156] In some embodiments, the set angle is an angle calculated based on the overlap of the target laser processing track 1 and a formula.

[0157] Since polygon scanning requires polygons to be periodically non-overlapping, the angle of a polygon cycle is not equal to 360°. Therefore, it can be achieved by increasing or decreasing the cycle angle. Here, taking the reduction of the cycle angle as an example, for example, if the overlap is expected to be 8%, it is necessary to reduce 360°*0.08=28.8°, and the polygon cycle angle is 360°-28.8°=331.2°. The corresponding polygon takes the set angle of 331.2°÷5=66.24°.

[0158] In some embodiments, the method of generating the laser processing trajectory 1 in the strip-shaped area 7 in step S2000 may be a variable trajectory method.

[0159] The steps of generating laser processing trajectory 1 by variable trajectory method include:

[0160] S2050: The strip-shaped area 7 includes a first reference line 2 and a second reference line 3, and the first reference line 2 and the second reference line 3 are respectively elliptical, forming a plurality of mutually surrounding or intersecting elliptical laser processing tracks 1 in the strip-shaped area 7.

[0161] Referring to Figures 12(a) and 12(b), this embodiment generates a laser processing trajectory 1 using a variable trajectory method, and the strip area 7 includes the first reference line 2 and the second reference line 3, and the first reference line 2 and the second reference line 3 are respectively elliptical. Variable trajectory refers to subdividing the strip area 7 into a plurality of mutually non-intersecting elliptical laser processing trajectories 1, and forming the laser processing trajectory 1 according to the set intervals and sequence. The advantage of the laser processing trajectory 1 using the variable trajectory method is that it reduces the intersection points of the laser processing trajectory 1, thereby achieving more uniform energy output. Figure 12(a) is a laser processing trajectory diagram formed by the equally divided contour line method, and Figure 12(b) is a laser processing trajectory diagram formed by the variable trajectory filling line segment method.

[0162] The laser processing trajectory 1 of the equally divided contour line method is a non-overlapping line segment, and the laser processing trajectory 1 of the track-changing filling line segment method is a line segment that intersects into points, which can effectively reduce the irradiation time of the laser spot at a certain point, thereby reducing the energy density.

[0163] In summary, a laser processing method in an embodiment of the present application expands the original trajectory of the laser from a single line segment to a strip area 7 of a set width, plans the laser trajectory within the strip area 7, and performs laser trajectory processing accordingly. This can make the laser trajectory more evenly distributed and have a certain regularity. At the same time, it expands the irradiation area of ​​the laser spot and reduces the irradiation time of the laser spot at a certain point on the plane, thereby achieving a more uniform output of laser energy and reducing manufacturing defects such as spattering caused by local energy imbalance, which will greatly improve the performance of the traditional swinging trajectory.

[0164] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A laser processing method, characterized in that: The steps include: Forming a strip area of ​​a set width (7); Generating a laser processing trajectory (1) in the strip-shaped area (7), wherein the laser processing trajectory (1) includes non-overlapping line segments and / or line segments that intersect to form points; Performing laser processing in the strip-shaped area (7) according to the laser processing trajectory (1); The step of forming a strip region (7) of a set width comprises: forming a first reference line (2); Decomposing the first reference line (2) into a plurality of straight line segments; Taking the decomposed plurality of straight line segments as a reference, each line segment is translated inwardly in a vertical direction of the line segment by a set width to form a second reference line (3), and the first reference line (2) and the second reference line (3) enclose a strip area (7) of the set width.

2. The method according to claim 1, characterized in that: The step of forming a strip region (7) of a set width may also be: forming a first reference line (2); Decomposing the first reference line (2) into a plurality of curve segments with gentle curvature; The entire curve is shifted by translating the curve control points according to the Bezier curve (12) to obtain a second reference line (3), wherein the first reference line (2) and the second reference line (3) enclose a strip area (7) of the set width.

3. The method according to claim 1, characterized in that: The step of forming a strip region (7) of a set width may also be: forming a first reference line (2), wherein the first reference line (2) is circular; Randomly select the first vertex on the first baseline (2); According to the first vertex, a plurality of vertices are sequentially selected on the first reference line (2) using the same set angle interval; Connecting the plurality of vertices to form an area where line segments intersect each other; The area where the line segments intersect each other forms a contour of a circle concentric with the first reference line (2) as the second reference line (3); The first reference line (2) and the second reference line (3) enclose a strip area (7) of a set width.

4. The method according to claim 3, characterized in that: The angles of the central angles formed by two adjacent vertices and the center of the circle are sequentially taken as the set angle.

5. The method according to claim 3 or 4, characterized in that: The set angle is an angle calculated based on the overlap of the target laser processing trajectory (1) and a formula.

6. The method according to claim 1, characterized in that: The strip-shaped area (7) has the first reference line (2) and the second reference line (3); the first reference line (2) and the second reference line (3) are respectively closed-loop curves; and the strip-shaped area (7) is a body of equal width.

7. The method according to any one of claims 1 to 3 and 6, characterized in that: The first reference line (2) is any one of the following: a circle, an ellipse, or any smooth boundary curve described by a Bezier curve equation or a spline curve equation.

8. The method according to claim 1, characterized in that: Generating a laser processing trajectory (1) in the strip-shaped area (7) comprises the following steps: The strip-shaped area (7) includes the first reference line (2) and the second reference line (3), and the first reference line (2) and the second reference line (3) are divided at a set step length within the strip-shaped area (7) to form a division point; The dividing points are alternately connected to form a reciprocating broken line laser processing trajectory (1).

9. The method according to claim 1, characterized in that: Generating a laser processing trajectory (1) in the strip-shaped area (7) comprises the following steps: The strip area (7) comprises the first reference line (2) and the second reference line (3), the first reference line (2) is circular, vertices are taken on the first reference line (2) using the same set angle interval, and the vertices are connected to form a polygonal scanning trajectory.

10. The method according to claim 9, characterized in that: The angles of the central angles formed by two adjacent vertices and the center of the circle are sequentially taken as the set angle.

11. The method according to claim 10, characterized in that The set angle is an angle calculated based on the overlap of the target laser processing trajectory (1) and a formula.

12. The method according to claim 1, characterized in that Generating a laser processing trajectory (1) in the strip-shaped area (7) comprises the following steps: The strip-shaped area (7) comprises the first reference line (2) and the second reference line (3), the first reference line (2) and the second reference line (3) are respectively elliptical, and a plurality of mutually surrounding or intersecting elliptical laser processing tracks (1) are formed in the strip-shaped area (7).

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