Linear laser engraving method and laser engraving machine

Abstract

The invention relates to the technical field of laser processing, in particular to a linear laser engraving method and a laser engraving machine. The linear laser engraving method comprises the steps that a laser engraving path is obtained according to an engraving line pattern, the laser engraving path comprises a plurality of line segments, and the laser engraving path is split into a plurality of target line segment laser engraving paths; acquiring a moving path of a laser engraving head according to the laser engraving path; in combination with the engraving parameters, speed changes of the laser engraving head when the laser engraving head goes through the laser engraving paths of the target line segments are obtained; and the moving path or / and the laser projection state of the laser engraving head are / is adjusted, so that the energy per unit length of the laser projected to the laser engraving path of the original target line segment is within the error range. The carving depth of the carved pattern is consistent, and the visual sense is good.

Description

Technical Field

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

[0002] With the miniaturization of lasers, many small and medium-sized laser engraving machines are now gradually being widely used. When using small and medium-sized laser engraving machines, the graphics to be engraved are generally input into the control system of the laser engraving machine. The control system generates a travel route for the laser engraving head according to the graphics to be engraved, and then controls the laser engraving head of the laser engraving machine to move according to the travel route, and projects the laser onto the surface of the workpiece to be processed at the place where engraving is required; the surface of the workpiece is then formed with an engraved pattern.

[0003] In actual work, the applicant found that many carved line patterns have local transitional carved areas, most of which are concentrated at intersections, corners, etc., causing obvious differences from other areas, often affecting the visual perception of the carved patterns. Summary of the invention

[0004] The object of the present invention is to provide a linear laser engraving method to address the deficiencies of the prior art. The laser engraving method can avoid over-processing of an area on a workpiece or reduce the area over-processed, and the processed workpiece has a better visual appearance.

[0005] A linear laser engraving method, comprising: Acquire a laser engraving path according to the engraving line pattern, the laser engraving path includes a plurality of line segments, and the laser engraving path is split into a plurality of target line segment laser engraving paths according to the plurality of line segments; According to the laser engraving path, the moving path of the laser engraving head is obtained; Obtaining the speed change of the laser engraving head when it passes through each target line segment laser engraving path; The moving path of the laser engraving head and / or the laser projection state are adjusted so that the energy per unit length of the laser projected onto the target line segment laser engraving path is equal or within the error range.

[0006] Further, when adjusting the moving path of the laser engraving head, when an acceleration branch segment appears on the target line segment laser engraving path, the target line segment laser engraving path extends backward to form an acceleration extension segment; or / and, when a deceleration branch segment appears on the target line segment laser engraving path, the target line segment laser engraving path extends forward to form a deceleration extension segment; according to the target line segment laser engraving path and the acceleration extension segment or / and the deceleration extension segment, a new moving path of the laser engraving head is formed, and the acceleration branch segment or / and the deceleration branch segment on the target line segment laser engraving path is eliminated.

[0007] Furthermore, when adjusting the laser projection state, when the laser engraving head passes through the target line segment laser engraving path, the laser projection power P is proportional to the speed V of the laser engraving head movement, P=K*V; K is the predetermined laser energy obtained per unit length on the laser engraving path.

[0008] Further, when adjusting the moving path of the laser engraving head, when forming an acceleration extension segment, if a part of the acceleration extension segment is located outside the processing area, the intersection of the acceleration extension segment and the boundary of the processing area is obtained, and a new moving path of the laser engraving head is formed; at the same time, a new acceleration segment length is obtained, and the two end points of the acceleration segment are respectively the intersection point and the point in the middle of the corresponding line segment; when the laser engraving head passes through the acceleration segment on the corresponding line segment, the power P of the laser projection is proportional to the speed V of the laser engraving head movement, P=K*V; K is the predetermined laser energy obtained per unit length on the laser engraving path.

[0009] Preferably, when forming a deceleration extension segment, if a part of the deceleration extension segment is located outside the processing area, the intersection of the deceleration extension segment and the boundary of the processing area is obtained, and a new movement path of the laser engraving head is formed; at the same time, a new deceleration segment and the length of the deceleration segment are obtained, and the two end points of the deceleration segment are respectively the intersection and the point in the middle of the corresponding line segment; when the laser engraving head passes through the deceleration segment on the corresponding line segment, the power P of the laser projection is proportional to the speed V of the laser engraving head movement, P=K*V; K is the predetermined laser energy obtained per unit length on the laser engraving path.

[0010] Furthermore, the coincidence point on the laser engraving path and several line segments corresponding to the coincidence point are obtained; one line segment corresponding to the coincidence point is retained, and other line segments corresponding to the coincidence point are disconnected at the coincidence point to form a new laser engraving path.

[0011] Preferably, when the coincident point is an endpoint of a target line segment and needs to be interrupted, the endpoint of the target line segment shrinks inward by a predetermined distance.

[0012] Furthermore, the coincidence point on the laser engraving path and several line segments corresponding to the coincidence point are obtained; a line segment corresponding to the coincidence point is selected; a laser blocking mechanism is set, and when the laser engraving head moves along other line segments and reaches the coincidence point, the laser blocking laser action is blocked to block the laser from being projected to the coincidence point, and when the laser engraving head passes the coincidence point, the laser blocking mechanism no longer blocks the laser projection.

[0013] Further, when the acceleration branch section and the deceleration branch section are both located outside the laser engraving path and within the processing area, when the laser engraving head passes outside the laser engraving path, the laser blocking mechanism blocks the laser.

[0014] A laser engraving machine comprises a laser emitter, a two-dimensional planar moving mechanism, a laser engraving head and a control system. The two-dimensional planar moving mechanism is connected to the laser engraving head, and the control system is electrically connected to the laser emitter and the two-dimensional planar moving mechanism. The control system controls the movement of the laser emitter and the two-dimensional planar moving mechanism and executes the above-mentioned linear laser engraving method.

[0015] Preferably, a laser blocking mechanism is further included, the laser blocking mechanism is located between the laser transmitter and the laser engraving head, and the laser blocking mechanism is electrically connected to the control system.

[0016] Beneficial effects of the present invention: The present invention adjusts the moving path of the laser engraving head and / or the laser projection state so that the energy per unit length of the laser projected onto the original target line segment laser engraving path is within the error range, so that the engraving depth of the engraved graphics is roughly the same and the visual sense is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a laser engraving path for laser processing in this embodiment.

[0018] Figure 2 A schematic diagram of the movement path of a laser engraving head in laser processing of this embodiment.

[0019] Figure 3 A partial schematic diagram of the movement path of a laser engraving head in laser processing of this embodiment.

[0020] Figure 4 It is a partial schematic diagram of another moving path of the laser engraving head in the laser processing of this embodiment.

[0021] Figure 5 This is a partial schematic diagram of the third laser engraving head moving path for laser processing in this embodiment.

[0022] Figure 6 It is a schematic diagram of the structural principle of the laser engraving machine of this embodiment.

[0023] Figure 7 The figure is a schematic diagram of a variation of the laser engraving path of the laser engraving head in this embodiment.

[0024] Reference numerals: 1 - laser engraving path; 2 - acceleration branch section; 3 - deceleration branch section; 4 - acceleration extension section; 5 - deceleration extension section; 6 - processing area; 7 - laser emitter; 8 - blocking block; 9 - laser blocking mechanism; 10 - laser engraving head; 11 - moving path. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] The present invention will be described in detail below with reference to the accompanying drawings. Figures 1 to 6 shown.

[0027] Example 1: See Figures 1 to 3 ; A linear laser engraving method, comprising: Acquire a laser engraving path 1 according to the engraving line pattern, the laser engraving path 1 includes a plurality of line segments, and the laser engraving path 1 is split into a plurality of target line segment laser engraving paths; According to the laser engraving path 1, a moving path 11 of the laser engraving head 10 is obtained; In combination with the engraving parameters, the speed change of the laser engraving head 10 when passing through each target line segment laser engraving path is obtained; The moving path 11 of the laser engraving head 10 and / or the laser projection state are adjusted so that the energy per unit length of the laser projected onto the original target line segment laser engraving path is equal or within the error range, which is generally within 5%.

[0028] The laser engraving path 1 is the path that the laser travels on the workpiece, and the moving path 11 is the moving path 11 of the laser engraving head 10 driven by the driving mechanism during the engraving process. It can be understood that: the laser engraving path 1 may have discontinuities, while the moving path 11 is continuous; therefore, the moving path 11 covers the laser engraving path 1. In discontinuous places, when the laser engraving head 10 moves between the two, it can move according to the movement rules of the engraving system. For example, when the laser engraving two adjacent line segments, when moving from the end point of one line segment to the starting point of another line segment, the driving mechanism drives the laser engraving to move: 1. Prioritize longitudinal movement, then lateral movement; 2. It can also prioritize lateral movement, then longitudinal movement; 3. Of course, it can also move both horizontally and vertically at the same time. Figure 1 As shown, the laser engraving path 1 is: A→B→C→D→E and F→G→H→K; and the moving path 11 can be: A→B→C→D→E→F→G→H→K; see Figure 2 In this embodiment, the third method is adopted, and the laser engraving head 10 directly transitions.

[0029] In the specific implementation, the engraving line pattern is transmitted to the control system of the engraving machine, and the control system obtains the laser engraving path 1 according to the processing pattern. The laser engraving path 1 can be the outline of the processing pattern; the processing pattern is a pattern of line combination, which is a combination of multiple line graphics, and the line graphics can be a triangle, a rectangle, a parallelogram, etc. After obtaining the laser engraving path 1, the laser engraving path 1 is decomposed into multiple line segments, and multiple target line segment laser engraving paths are formed. These multiple target line segment laser engraving paths are connected in a predetermined manner to form a moving path 11 of the laser engraving head 10. When engraving a workpiece, each laser engraving machine has a default or set processing order, such as from left to right or combined with from top to bottom, or from inside to outside, or from outside to inside; according to the processing order, the processing order of each line segment can be obtained, and then the engraving path that the laser needs to travel and the moving path of the laser engraving head 10 are determined.

[0030] When laser engraving on workpieces, it is generally divided into four forms: fine tracing, shallow engraving, deep engraving, and cutting. Among them, fine tracing, shallow engraving, and deep engraving are different depth processes for engraving on the surface of the workpiece. Of course, there can be other classifications; when laser engraving, the engraving depth is related to the energy projected by the laser onto the unit area of ​​the workpiece surface. After selecting the process, the laser engraving machine system automatically sets the corresponding engraving speed, that is, the maximum engraving speed; when the depth of the pattern engraved on the workpiece needs to be roughly the same, the energy projected by the laser onto the surface of the workpiece needs to be uniform and roughly consistent.

[0031] At present, when the laser engraving head 10 moves, it is mainly driven by a plane two-dimensional moving mechanism, namely an X-axis moving mechanism and a Y-axis moving mechanism; when calculating, the corresponding XY coordinate system is first established, and the moving path 11 is decomposed into an X moving path and a Y moving path, and the moving acceleration is also divided into X acceleration and Y acceleration; the speed is divided into: X speed and Y speed; X acceleration and X speed are provided by the X-axis moving mechanism, and Y acceleration and Y speed are provided by the Y-axis moving mechanism, but the combined speed of X and Y is limited by the set speed and cannot exceed the set speed; such as the maximum X speed and Y speed is 1000mm / s, etc., X acceleration and Y acceleration are related to their own moving mechanism parameters, which can be set manually or based on the working rated parameters of the moving mechanism, such as X acceleration and Y acceleration are both 1g, etc.; the X-direction movement and Y-direction movement of the laser engraving head 10 are calculated respectively; the speed and time point of the laser engraving head 10 at each point on the moving path 11 are obtained, and the speed change of the laser engraving head 10 when it passes through each target line segment laser engraving path can also be obtained.

[0032] At present, when the laser is engraving the workpiece and is in the same engraving process, the projection power of the laser remains basically unchanged, that is, the laser emitter 7 maintains a constant power to work and emits a constant power laser to the outside; while the laser engraving head 10 moves under the drive of the driving mechanism, due to the discontinuity and multi-segment nature of the line segments on the laser engraving path 1, the moving speed of the laser engraving head 10 on the laser engraving path 1 cannot be kept uniform; see Figure 3 , Figure 4 Basically, each line segment has a short acceleration branch segment 2 and a deceleration branch segment 3. Since the moving speed of the laser engraving head 10 on the acceleration branch segment 2 and the deceleration branch segment 3 is lower than the set moving speed, the laser energy obtained on the acceleration branch segment 2 and the deceleration branch segment 3 on the workpiece is relatively large, and the engraving depth on the workpiece is also relatively deep, resulting in inconsistent processing and large visual differences.

[0033] Only when the laser energy obtained per unit length on the laser engraving path 1 on the workpiece is the same or approximately the same, can the engraved pattern on the workpiece have no obvious viewing angle difference; to achieve this purpose, the present application adopts a method of adjusting the target segment laser engraving path and / or the laser state, such as 1. Adjusting the target segment laser engraving path, the moving path 11 of the laser engraving head 10 can be adjusted so that the laser engraving head 10 maintains a normal average speed when passing through the target segment laser engraving path; 2. Adjusting the laser state, adjusting the energy change of the laser projected onto the target segment laser engraving path, so that the energy change is consistent with the speed change. 3. Adjusting the target segment laser engraving path and the laser state. When directly adjusting the energy change of the laser projection, it may not match the speed. For example, the startup time of the laser emitter 7 is relatively long. Therefore, it is necessary to adjust the target segment laser engraving path in combination so that the laser adjustment can keep up with the speed adjustment, and the two adjustments are consistent.

[0034] Secondly, it should be noted that when the engraving material is selected, the engraving laser emitter 7 is selected, and the engraving process is selected, the moving speed of the laser engraving head 10 is also determined, that is, the moving speed of the laser on the target line segment laser engraving path is determined; this speed is the maximum speed and also the predetermined processing speed.

[0035] When determining the speed change of the target line segment laser engraving path, since the laser engraving head 10 is driven by a two-dimensional plane moving mechanism, the two-dimensional plane moving driving mechanism includes an X moving mechanism and a Y moving mechanism, the movement of the laser engraving head 10 can be synthesized by the movement in the X direction and the movement in the Y direction, and the accelerations of the laser engraving head 10 driven by the X moving mechanism and the Y moving mechanism are both constant, and the acceleration values ​​of the two can be equal or different; the laser engraving head 10 moves along the moving path 11, When the laser engraving head moves along a certain target line segment laser engraving path, the speed change of the laser engraving head 10 when moving along this target line segment laser engraving path can be calculated based on the length of the target line segment laser engraving path, the speed when entering the end point of the target line segment laser engraving path, the acceleration of the laser engraving head 10, and the maximum speed when moving along the target line segment laser engraving path.

[0036] See also Figure 3 , Figure 4 When adjusting the moving path 11 of the laser engraving head 10, when an acceleration branch segment AM appears on the target line segment laser engraving path AB, the target line segment laser engraving path extends backward to form an acceleration extension segment AM; or / and, when a deceleration branch segment BN appears on the target line segment laser engraving path, the target line segment laser engraving path extends forward to form a deceleration extension segment Bn; again, according to the laser engraving path 1 and the acceleration extension segment 4 or / and the deceleration extension segment 5, a new laser engraving path 1 is formed, and the acceleration branch segment 2 or / and the deceleration branch segment 3 on the target line segment laser engraving path are eliminated.

[0037] At present, when a laser engraving machine performs a certain process engraving on a workpiece (except the cutting process), the power of its laser emitter 7 is generally constant; therefore, in the acceleration branch section 2 or the deceleration branch section 3, the dwelling time is relatively long, resulting in a relatively deep engraving depth; in order to change this situation, the acceleration branch section 2 and the deceleration branch section 3 are removed from the laser engraving path 1 in this embodiment; by extending the original line segment in the length direction, when the acceleration branch section 2 appears, the line segment is extended backward to form an acceleration extension section 4; Figure 2 , Figure 3 The original line segment is line segment AB. When there is an acceleration branch segment AM, line segment AB extends backward to form an acceleration extension segment Am. When the laser engraving head 10 needs to engrave the original line segment AB, the laser engraving head 10 does not move directly to point A, but moves to point m, and starts to move at an accelerated speed at point m. When it reaches point A, the speed of the laser engraving head 10 has reached the maximum speed, and it can move at a constant speed. At this time, the laser emitter 7 emits laser, and the laser engraving path 1 of the laser is still the AB segment. When there is a deceleration branch segment Bn, line segment AB extends forward to form a deceleration extension segment Bn. The laser engraving head 10 always passes through the line segment AB at the maximum speed, and then passes through the deceleration extension segment Bn in a decelerated manner. The laser emitter 7 works when the laser engraving head 10 passes through the line segment AB, and does not emit laser when passing through the deceleration extension segment Bn.

[0038] By adding the acceleration extension section 4 and the deceleration extension section 5, the laser engraving head 10 can keep moving at the average maximum speed when passing through the target line segment laser engraving path. The energy per unit length of the laser projected to all target line segment laser engraving paths is equal or approximately equal. When planning the moving path 11 of the laser engraving head 10, the acceleration extension section and the deceleration extension section are included. There are many ways to plan the moving path 11. For example, the line segments of the laser engraving path 1 can be directly sorted, and a certain rule can be followed when arranging the lines, such as giving priority to left to right, then from top to bottom; or giving priority to from inside to outside, then from left to right, etc.; then connect the two adjacent line segments in turn; when connecting, you can choose the principle of proximity, and connect the tail end of the previous line segment to the nearest endpoint of the next line segment; you can also choose to connect to the leftmost endpoint of the next line segment or the topmost endpoint, etc.; when there is an acceleration extension segment or / and a deceleration extension segment, directly replace the original line segment with a line segment with an acceleration extension segment or / and a deceleration extension segment, and form a new moving path 11 of the laser engraving head 10 again, but the laser engraving path 1 remains unchanged.

[0039] Secondly, the length of the acceleration extension branch is greater than or equal to the length of the original acceleration branch 2, and the length of the deceleration extension branch is greater than or equal to the length of the original deceleration branch 3. This ensures that the laser engraving head 10 has a uniform speed and a set speed when passing through the target line segment laser engraving path.

[0040] In another way, when adjusting the laser projection state, when the laser engraving head 10 passes through the target line segment laser engraving path, the power P of the laser projection is proportional to the speed V of the laser engraving head 10, P=K*V; K is the predetermined laser energy obtained per unit length on the laser engraving path 1.

[0041] When the laser engraving head 10 passes through the target line segment laser engraving path, when there is an acceleration branch segment 2 or a deceleration branch segment 3 in the target line segment laser engraving path, the speed of the acceleration branch segment 2 or the deceleration branch segment 3 is set to V(t), and the laser projection power is P(t). Within the △t time, the travel distance of the acceleration branch segment 2 or the deceleration branch segment 3 is L=V(t)*△t, and the energy of the laser projection is: W=P(t)*△t.

[0042] The projected energy per unit length is: △Q=W / L=P(t) / V(t).

[0043] To keep the engraving depth consistent, ΔQ needs to remain constant; therefore, the speed is proportional to the projected power; changes in the laser projected power are consistent with changes in the speed of the laser engraving head 10 .

[0044] Secondly, when engraving, the moving speed of the laser engraving head 10 is set to V0, which is the speed of the laser engraving head 10 in the average speed branch section and is also the maximum speed; the emission power of the laser emitter 7 is set to P0, which is also the laser projection power in the average speed branch section. It can be seen from this that: △Q=P0*△t / (V0*△t)=P0 / V0.

[0045] For example, V0 can be the speed of the laser engraving head 10 in the average speed branch section; P0 is the power of the laser projection in the average speed branch section, and it can be known that △Q=P0 / V0, that is, K= P0 / V0.

[0046] The laser power projection of the acceleration branch 2 or the deceleration branch 3 is: P(t)=W / △t =△Q*L / △t = (P0 / V0)*( V(t)* △t) / △t= (P0 / V0)* V(t).

[0047] P(t)= (P0 / V0)* V(t).

[0048] It is understandable that, during engraving, the acceleration of the acceleration branch section 2 and the acceleration of the deceleration branch section 3 can be set to be constant, that is, the accelerations are kept consistent.

[0049] Set the speed of acceleration segment 2 to: V(t)=V1+a*t; the speed of deceleration segment 3 to: V(t)=V2-a*t; a is the acceleration, V1 and V2 are the initial speeds of acceleration segment 2 and deceleration segment 3 respectively.

[0050] The laser power projection of the acceleration branch 2 is: P(t)= (P0 / V0)* V(t)= (P0 / V0)*(V1+a*t).

[0051] The laser power projection of the deceleration branch section 3 is: P(t)= (P0 / V0)* V(t)= (P0 / V0)*(V2-a*t).

[0052] Since the acceleration branch segment 2 and the deceleration branch segment 3 are only for the target line segment, the above function is a piecewise function. In the above formula: P0, V0, a ​​are all parameter setting values, V1 and V2 can be obtained according to the moving path 11 of the entire laser engraving head 10, such as: when the starting point of the acceleration branch segment 2 is the initial point, V1=0; when the starting point of the deceleration branch segment 3 is the end point of the average speed branch segment, V2=V0; if not, V2=V1+at1; t1 is the time taken by the laser engraving head 10 to experience the acceleration branch segment 2.

[0053] See also Figure 4 , Figure 5When adjusting the moving path 11 of the laser engraving head 10, when the acceleration extension segment Am is formed, if a part of the acceleration extension segment Am is located outside the processing area 6, the intersection point p of the acceleration extension segment 4 and the boundary of the processing area 6 is obtained, and a new moving path 11 of the laser engraving head 10 is formed; at the same time, the new acceleration segment pa length is obtained, and the two end points of the acceleration segment pa are respectively the intersection point p and the point a in the middle of the corresponding line segment; when the laser engraving head 10 passes through the acceleration segment pa part (line segment Aa) on the corresponding line segment, the power P of the laser projection is proportional to the speed V of the laser engraving head 10 movement, P=K*V; K is the predetermined laser energy obtained per unit length on the laser engraving path 1.

[0054] Considering that the moving range of the laser engraving head 10 is limited by the processing area 6, the laser engraving head 10 needs to be limited to move within the processing area 6. If a part of the acceleration extension segment mA (line segment mp) is outside the processing area 6, this part needs to be removed and the moving path 11 needs to be replanned; since the acceleration and the maximum speed are both preset, the initial speed is set to 0, the length of the acceleration segment pa and the position of the acceleration segment pa can be obtained, and a part of the acceleration segment pa (line segment Aa) coincides with the corresponding target line segment. When the laser engraving passes through the overlapping part (line segment Aa), the laser is projected onto the path of the overlapping part, and the power P of the laser projection is proportional to the speed V of the laser engraving head 10, P=K*V; K is the predetermined laser energy obtained per unit length on the laser engraving path 1; after the engraving material and engraving process are selected, the laser energy obtained per unit length on the laser engraving path 1 is correspondingly predetermined.

[0055] It can be understood that: when the entire acceleration extension section 4 is located outside the processing area 6, it can be treated as if no acceleration extension section 4 is set. In this embodiment, an acceleration section is set. Due to the limitation of the processing range, a part of the acceleration section is located on the corresponding target line segment of laser engraving. This part uses a corresponding proportion of laser energy to project during engraving, so that the laser energy per unit length on the laser engraving path 1 is roughly equal or equal, and the engraving depth is also roughly the same. In this embodiment, the length of the acceleration section on the laser engraving path 1 is the smallest, which reduces the acceleration distance of the laser engraving head 10 on the laser engraving path 1, making the laser engraving head 10 more stable on the laser engraving path 1.

[0056] See also Figure 5When the deceleration extension segment Bn is formed, if a part of the deceleration extension segment Bn (line segment qn) is located outside the processing area 6, the intersection q between the deceleration extension segment Bn and the boundary of the processing area 6 is obtained, and a new moving path 11 of the laser engraving head 10 is formed; at the same time, a new deceleration segment bq and the length of the deceleration segment bq are obtained, and the two end points of the deceleration segment bq are respectively the intersection q and the point b in the middle of the corresponding line segment; when the laser engraving head 10 passes through the deceleration segment on the corresponding line segment, the power P of the laser projection is proportional to the moving speed V of the laser engraving head 10, P=K*V; K is the predetermined laser energy obtained per unit length on the laser engraving path 1.

[0057] The laser engraving head 10 is restricted by the processing area 6. If a part of the deceleration extension section 5 is outside the processing area 6, this part needs to be removed; and the moving path 11 of the laser engraving head 10 is replanned; when the acceleration and the maximum moving speed are both preset, and the initial speed is 0; the length and position of the deceleration section can be obtained according to the moving path 11, and a part of the deceleration section coincides with the corresponding target line segment. When the laser engraving head 10 passes through the overlapping part, the laser is projected onto the path of the overlapping part, and the power P of the laser projection is proportional to the speed V of the laser engraving head 10, P=K*V; K is the predetermined laser energy obtained per unit length on the laser engraving path 1; after the engraving material and engraving process are selected, the laser energy obtained per unit length on the laser engraving path 1 is correspondingly predetermined.

[0058] It can be understood that: when the entire deceleration extension section 5 is located outside the processing area 6, then it can be treated as if no deceleration extension section 5 is provided. In this embodiment, a deceleration section is provided. Due to the limitation of the processing range, a part of the deceleration section is located on the corresponding target line segment of the laser engraving. This part uses a corresponding proportion of laser energy to be projected during engraving, so that the laser energy per unit length on the laser engraving path 1 is approximately equal or equal, and the engraving depth is also approximately the same. In this embodiment, the length of the deceleration section on the laser engraving path 1 is the smallest, which reduces the deceleration distance of the laser engraving head 10 on the laser engraving path 1, making the laser engraving head 10 more stable on the laser engraving path 1.

[0059] Further, the coincidence point on the laser engraving path 1 and several line segments corresponding to the coincidence point are obtained; one line segment corresponding to the coincidence point is retained, and the other line segments corresponding to the coincidence point are disconnected at the coincidence point to form a new laser engraving path 1, see Figure 7 .

[0060] There are few engraved patterns without overlap points. At the overlap points, multiple laser projections will cause repeated acquisition of laser energy at the overlap points. The engraving depth at the overlap points is deeper than that at other places, and the color is also deeper. In order to avoid repeated laser projection at the overlap points, in this embodiment, one of the line segments passing through the overlap points is selected and kept unchanged, and the other line segments are interrupted at the overlap points, such as Figure 7 In the example, line segment QK is the selected line segment and remains unchanged; line segment RS, line segment TV, line segment UW, line segment XY and line segment ZH are all interrupted; when the laser engraving head 10 passes through the interruption point, the laser emitter 7 stops working temporarily, so that the projected energy of the laser at the coincidence point remains unchanged. When selecting the reserved line segment, the line segment can be randomly selected, or the first or last line or other ranking can be selected in the engraving order.

[0061] Preferably, when the coincident point is an endpoint of a target line segment and needs to be interrupted, the endpoint of the target line segment shrinks inward by a predetermined distance.

[0062] In the engraving graphics, many line segments are connected end to end; at the endpoint, two adjacent line segments overlap. In order to prevent the laser from repeatedly projecting energy at the endpoint as the overlap point, the endpoint needs to be interrupted and retracted inward by a predetermined distance; the predetermined distance can be set manually, such as a suitable predetermined distance can be set based on multiple tests. This makes the adjacent line segments not connected at the overlap, with a tiny gap, which is difficult for the human eye to detect. The predetermined distance can be: 0.1mm to 0.5mm, such as 0.2mm, 0.3mm, etc.

[0063] Further, obtain the coincidence point on the laser engraving path 1 and several line segments corresponding to the coincidence point; select a line segment corresponding to the coincidence point, see Figure 7 ; See Figure 6 A laser blocking mechanism 9 is set. When the laser engraving head 10 moves along other line segments and reaches the overlap point, the laser blocking mechanism 9 is activated to block the laser from being projected to the overlap point. When the laser engraving head 10 passes the overlap point, the laser blocking mechanism 9 no longer blocks the laser projection.

[0064] In order to prevent the laser from being repeatedly projected to overlapping points, another method is provided in this embodiment. By providing a laser blocking mechanism 9 to control the projection of the laser, frequent startup and standby of the laser emitter 7 can be avoided.

[0065] When the laser engraving head 10 moves, it is driven by the planar two-dimensional moving mechanism, and the planar two-dimensional moving mechanism and the laser emitter 7 are controlled by the control system, so that the laser is projected at an accurate position; this embodiment adds a laser blocking mechanism 9, and the laser blocking mechanism 9 is also controlled by the control system. When engraving is normal, the laser blocking mechanism 9 will not block the laser projection; when the laser engraving head 10 moves to the overlap point, the laser blocking mechanism 9 blocks the laser, and when the laser engraving head 10 leaves the overlap point, the laser blocking mechanism releases the blocking of the laser.

[0066] The laser blocking mechanism 9 can adopt a variety of structures and can also be set at multiple positions. The structure can be: including a blocking block, the blocking block is located on one side of the laser projection path, the blocking block is connected to the linear module, the linear module is electrically connected to the control system, the control system controls the linear module to drive the blocking block to move, when it is necessary to block the laser and the laser engraving head 10 moves to the overlap point, the control system controls the linear module to drive the blocking block to move, the laser engraving head 10 passes through the overlap point, the blocking block blocks the laser, the laser engraving head 10 leaves the overlap point, and the blocking block 8 leaves the laser track; it can also be adopted: including a blocking block 8, the middle of the blocking block 8 is provided with a light-transmitting hole for the laser to pass through, the blocking piece is connected to the servo motor, the servo motor is electrically connected to the control system and is controlled by the control system, when it is necessary to block the laser and the laser engraving head 10 moves to the overlap point, the servo motor controls the blocking block 8 to rotate, and when the laser engraving head 10 leaves the overlap point, the blocking block 8 rotates 180 degrees or 360 degrees. The laser blocking laser can be set at any position on the laser projection path.

[0067] Further, when the acceleration branch section 2 and the deceleration branch section 3 are both located outside the laser engraving path 1 and within the processing area 6 , when the laser engraving head 10 passes outside the laser engraving path 1 , the laser blocking mechanism 9 blocks the laser.

[0068] When the acceleration branch section 2 and the deceleration branch section 3 are both outside the laser engraving path 1 and within the processing area 6, the laser engraving head 10 is in a uniform speed state and at a maximum moving speed when passing through the laser engraving path 1; therefore, the laser emitter 7 can maintain a working state from beginning to end, and when the laser engraving head 10 passes through a non-engraving position, the laser blocking mechanism 9 blocks the laser. This can avoid the laser emitter 7 from working unstably or affecting its service life due to continuous adjustment.

[0069] Embodiment 2: A laser engraving machine comprises a laser emitter 7, a planar two-dimensional moving mechanism, a laser engraving head 10 and a control system. The planar two-dimensional moving mechanism is connected to the laser engraving head 10, and the control system is electrically connected to the laser emitter 7 and the planar two-dimensional moving mechanism. The control system controls the movement of the laser emitter 7 and the planar two-dimensional moving mechanism and executes the above-mentioned linear laser engraving method.

[0070] The two-dimensional plane moving mechanism can be an existing technology, such as an XY moving mechanism, that is, an integration of an X moving mechanism and a Y moving mechanism, which is used to drive the laser engraving head 10 to move horizontally and vertically. The laser emitter 7 can be directly installed on the laser engraving head 10, or it can be installed on the fuselage. The fuselage and the two-dimensional plane moving laser are provided with a laser reflector. Through the laser reflector, the laser emitter 7 projects the laser to the laser engraving head 10. This technology can also be an existing technology. During operation, the control system controls the laser emitter 7 and the two-dimensional plane moving mechanism to move and execute the laser processing method of implementation 1 to process the workpiece.

[0071] See also Figure 6 , and also includes a laser blocking mechanism 9, which is located between the laser emitter 7 and the laser engraving head 10, and the laser blocking mechanism 9 is electrically connected to the control system.

[0072] The control system can adopt MCU, DSP (Digital Signal Process), FPGA (Field Programmable Gate Array), PLC, SOC (System OnChip), IC (integrated circuit), etc.

[0073] The laser blocking mechanism 9 is used to block the laser projection; it can make the laser emitter 7 keep working when the laser engraving head 10 passes through the moving path 11. When the laser engraving head 10 passes through the laser engraving path 1, the blocking block 8 of the laser blocking mechanism 9 is located on one side of the laser path or is provided with a light-transmitting hole for the laser to pass through; when the laser engraving head 10 passes outside the laser engraving path 1, the blocking block 8 blocks the laser projection. The laser blocking mechanism 9 can avoid the laser emitter 7 from frequently adjusting its state and maintain its working stability.

[0074] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, according to the concept of the present invention, there will be changes in the specific implementation methods and application scopes. The content of this specification should not be understood as limiting the present invention.

Claims

1. A linear laser engraving method, characterized in that: It includes: Acquire a laser engraving path according to the engraving line pattern, the laser engraving path includes a plurality of line segments, and the laser engraving path is split into a plurality of target line segment laser engraving paths; According to the laser engraving path, the moving path of the laser engraving head is obtained; Combined with the engraving parameters, the speed change of the laser engraving head when passing through each target line segment laser engraving path is obtained; the moving path of the laser engraving head and / or the laser projection state are adjusted so that the energy per unit length of the laser projected onto the target line segment laser engraving path is equal or within the error range.

2. The linear laser engraving method according to claim 1, characterized in that: When adjusting the moving path of the laser engraving head, when an acceleration branch segment appears on the laser engraving path of the target line segment, the laser engraving path of the target line segment is extended backward to form an acceleration extension segment; or / and, when a deceleration branch segment appears on the laser engraving path of the target line segment, the laser engraving path of the target line segment is extended forward to form a deceleration extension segment; again, a new laser engraving path is formed according to the laser engraving path and the acceleration extension segment or / and the deceleration extension segment, and the acceleration branch segment or / and the deceleration branch segment on the laser engraving path of the target line segment is eliminated.

3. The linear laser engraving method according to claim 1, characterized in that: When adjusting the laser projection state, when the laser engraving head passes through the target line segment laser engraving path, the laser projection power P is proportional to the speed V of the laser engraving head movement, P=K*V; K is the predetermined laser energy obtained per unit length on the laser engraving path.

4. The linear laser engraving method according to claim 2, characterized in that: When adjusting the moving path of the laser engraving head, when forming the acceleration extension segment, if a part of the acceleration extension segment is located outside the processing area, the intersection of the acceleration extension segment and the boundary of the processing area is obtained, and a new moving path of the laser engraving head is formed; at the same time, a new acceleration segment length is obtained, and the two end points of the acceleration segment are respectively the intersection point and the point in the middle of the corresponding line segment; when the laser engraving head passes through the acceleration segment on the corresponding line segment, the power P of the laser projection is proportional to the speed V of the laser engraving head movement, P=K*V; K is the predetermined laser energy obtained per unit length on the laser engraving path.

5. The linear laser engraving method according to claim 2 or 4, characterized in that: When adjusting the moving path of the laser engraving head, when a deceleration extension segment is formed, if a part of the deceleration extension segment is located outside the processing area, the intersection of the deceleration extension segment and the boundary of the processing area is obtained, and a new moving path of the laser engraving head is formed; at the same time, a new deceleration segment and the length of the deceleration segment are obtained, and the two end points of the deceleration segment are respectively the intersection and the point in the middle of the corresponding line segment; when the laser engraving head passes through the deceleration segment on the corresponding line segment, the power P of the laser projection is proportional to the speed V of the laser engraving head movement, P=K*V; K is the predetermined laser energy obtained per unit length on the laser engraving path.

6. The linear laser engraving method according to claim 1 or 2 or 3 or 4, characterized in that: The coincidence point on the laser engraving path and several line segments corresponding to the coincidence point are obtained; a line segment corresponding to the coincidence point is retained, and other line segments corresponding to the coincidence point are disconnected at the coincidence point to form a new laser engraving path; when the coincidence point is the endpoint of the target line segment and needs to be interrupted, the endpoint of the target line segment is retracted inward by a predetermined distance.

7. The linear laser engraving method according to claim 1 or 2 or 3 or 4, characterized in that: Obtain the coincidence point on the laser engraving path and several line segments corresponding to the coincidence point; select a line segment corresponding to the coincidence point; set a laser blocking mechanism, when the laser engraving head moves along other line segments and reaches the coincidence point, the laser blocking laser action is blocked to block the laser projection to the coincidence point, when the laser engraving head passes the coincidence point, the laser blocking mechanism no longer blocks the laser projection.

8. The linear laser engraving method according to claim 6, characterized in that: When the acceleration branch section and the deceleration branch section are both located outside the laser engraving path and within the processing area, the laser blocking mechanism blocks the laser when the laser engraving head passes outside the laser engraving path.

9. A laser engraving machine, comprising a laser emitter, a two-dimensional planar moving mechanism, a laser engraving head and a control system, wherein the two-dimensional planar moving mechanism is connected to the laser engraving head, and the control system is electrically connected to the laser emitter and the two-dimensional planar moving mechanism, characterized in that: The control system controls the actions of the laser emitter and the planar two-dimensional moving mechanism and executes the linear laser engraving method described in any one of claims 1 to 8.

10. The laser engraving machine according to claim 9, characterized in that: It also includes a laser blocking mechanism, which is located between the laser transmitter and the laser engraving head and is electrically connected to the control system.

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