阅读说明：本技术 一种分段连续激光雕刻方法 (Sectional continuous laser engraving method ) 是由 王红才 于 2020-05-07 设计创作，主要内容包括：本申请涉及一种分段连续激光雕刻方法,该方法包括：将聚焦头移动到雕刻的起始位置,启动主轴并加速至预设速度；控制所述聚焦头轴向后退至少一个螺距；采用主轴同步脉冲和周向基准脉冲控制激光开关,以及控制所述聚焦头的轴向运动,记录与所述主轴同步的脉冲数；当所述脉冲数与所述螺距的数量相同时,按照预设要求开关激光直至雕刻完整段短螺旋线；重复上述步骤依次雕完所有短螺旋线。该技术方案通过将一条长螺旋线分解成无缝拼接的多段短螺旋线,主轴同步脉冲对激光器控制信号的同步次数由一次变成多次,减少了累加偏差,提高了加工精度。(The application relates to a segmented continuous laser engraving method, which comprises the following steps: moving the focusing head to the carving initial position, starting the main shaft and accelerating to a preset speed; controlling the focusing head to axially retreat by at least one screw pitch; adopting a main shaft synchronous pulse and a circumferential reference pulse to control a laser switch, controlling the axial movement of the focusing head and recording the pulse number synchronous with the main shaft; when the number of the pulses is the same as that of the screw pitches, switching on and off the laser according to a preset requirement until the complete short spiral line is engraved; and repeating the steps to carve all the short spiral lines in sequence. According to the technical scheme, one long spiral line is decomposed into the seamlessly spliced multi-section short spiral lines, the number of times of synchronizing the main shaft synchronous pulse to the laser control signal is changed from one time to multiple times, the accumulated deviation is reduced, and the processing precision is improved.)

1. A method of segmented continuous laser engraving comprising:

step S11, moving the focusing head to the carving initial position, starting the main shaft and accelerating to the preset speed;

step S12, controlling the focusing head to axially retreat by at least one thread pitch;

step S13, adopting a main shaft synchronous pulse and a circumferential reference pulse to control a laser switch, controlling the axial movement of the focusing head, and recording the pulse number synchronous with the main shaft;

and step S14, when the number of pulses is the same as the number of the screw pitches, switching on and off the laser according to preset requirements until the complete short spiral line is engraved.

2. The method of claim 1, further comprising:

acquiring the carved number of the short spiral lines;

and when the engraved number meets the specified number, stopping the rotation of the main shaft, and confirming that the engraving of the long spiral line is finished.

3. The method of claim 2, further comprising:

when the engraved number does not satisfy the specified number, the steps S12-S14 are circularly executed until the engraved number satisfies the specified number.

4. The method of claim 1, wherein the spindle synchronization pulses are zero pulses of a spindle encoder or pulses offset from a circumferential reference pulse generated by one or more spindle encoders.

5. The method of claim 1, wherein switching the laser on and off according to preset requirements until a complete short spiral is engraved when the number of spindle sync pulses is the same as the number of pitch, the method further comprising:

adding an elongated segment based on the starting position of the short spiral;

turning off the laser while engraving an elongated segment of the short spiral, wherein the elongated segment is one or more circumferential lengths.

Technical Field

The application relates to the field of laser engraving, in particular to a segmented continuous laser engraving method.

Background

Laser engraving of image rollers has two modes, continuous and step-wise. For the purpose of processing efficiency, a continuous processing method is generally adopted: after the main shaft is started and rotates at a constant speed, the focusing head is axially started and moves at a constant speed, and a circumferential reference pulse generated by an encoder which is coaxially arranged with the main shaft controls the switch of the laser.

The processing trajectory of the continuous processing mode is a spiral line containing switching information for controlling the laser light in one-to-one correspondence with the position thereof. The laser signal has little lag with the electrical signal controlling it, and its start position is generated synchronously with the zero pulse of the encoder. Because of the inertia effect, the starting and stopping sections of the axial constant-speed movement of the focusing head are acceleration and deceleration processes, and the whole engraving process has lag. Because the axial engraving density of the starting section is increased, the stopping section is not engraved, and the width of the actually engraved roll surface is smaller than a preset value. According to the existing carving method, the carving of a section of long spiral line is divided into the carving of a plurality of sections of short spiral lines, so that abnormal grains are inevitably generated at the splicing position due to the axial acceleration and deceleration moving process of the focusing head, and the method cannot be used. In the existing processing technology, continuous processing cannot be interrupted, otherwise, the whole processing can be scrapped, and the loss is large. In addition, during the spiral line machining, the control signal of the laser is only synchronized once by the main shaft encoder, if the machining frequency is high, the position of the roller surface laser action point may have deviation, the deviation may be accumulated, and if the machining time is too long, the deviation is too large, the requirement of the machining precision may not be met.

The method has important significance if the defects of the existing continuous laser processing method can be avoided.

Disclosure of Invention

In order to solve the above technical problem or at least partially solve the above technical problem, the present application provides a segmented continuous laser engraving method.

The application provides a segmented continuous laser engraving method, which comprises the following steps:

moving the focusing head to the carving initial position, starting the main shaft and accelerating to a preset speed;

controlling the focusing head to axially retreat by at least one screw pitch;

adopting a main shaft synchronous pulse and a circumferential reference pulse to control a laser switch, controlling the axial movement of the focusing head and recording the pulse number synchronous with the main shaft;

and when the number of the pulses is the same as that of the screw pitches, switching on and off the laser according to a preset requirement until the complete short spiral line is engraved.

In one possible embodiment, the method further comprises:

acquiring the engraved number of the short spirals;

and when the engraved number meets the specified number, stopping the rotation of the main shaft, and confirming that the engraving of the long spiral line is finished.

In one possible embodiment, the method further comprises:

when the engraved number does not satisfy the specified number, the steps S12-S14 are circularly performed until the engraved number does not satisfy the specified number.

In one possible embodiment, the spindle synchronization pulse is a zero pulse of the spindle encoder, or a pulse offset from a circumferential reference pulse generated by one or more spindle encoders.

In a possible embodiment, when the number of pulses is the same as the number of pitches, the laser is switched on and off according to a preset requirement until a complete short spiral is engraved, and the method further comprises:

adding an elongated segment based on the starting position of the short spiral;

turning off the laser while engraving an elongated segment of the short spiral, wherein the elongated segment is one or more circumferential lengths.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages: a long spiral line is decomposed into a plurality of seamlessly spliced short spiral lines, and the synchronization times of the main shaft synchronous pulse to the laser control signal are changed from one time to a plurality of times, so that the accumulated deviation is reduced, and the processing precision is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

Fig. 1 is a flowchart of a segmented continuous laser engraving method provided in an embodiment of the present application;

fig. 2 is a timing diagram of a segmented continuous laser engraving method provided by an embodiment of the present application;

fig. 3 is a track diagram of a segmented continuous laser engraving method provided in an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

First, a method for laser engraving in a segmented and continuous manner according to an embodiment of the present invention will be described.

In this embodiment, the diameter of the roller is 200mm, the dot pitch of the engraved pattern is equal to the pitch of the screw, both are 0.1mm, the close-packed width of the long spiral line is 1000mm, and the engraving frequency is 30000 Hz. The acceleration time of the focusing head axial movement servo system is less than 20ms, and the resolution is 0.001 mm.

From the diameter of the roll, the dot pitch of the engraving pattern and the engraving frequency, the spindle speed should be 286 rpm. The close-packed width of the short spiral line is set to be 20mm, the length is 200 circumference lengths, and 50 sections of short spiral lines are required to be carved.

Fig. 1 is a flowchart of a segmented continuous laser engraving method provided in an embodiment of the present application, where the method includes the following steps:

step S11, moving the focusing head to the carving initial position, starting the main shaft and accelerating to the preset speed;

in this step, the laser is first turned off, and the focusing head is stopped after moving to the start position of the engraving. The spindle was started, accelerated to 286rpm, and held in constant rotation.

Step S12, controlling the focusing head to axially retreat by at least one thread pitch;

step S13, adopting the main shaft synchronous pulse and the circumferential reference pulse to control the laser switch, control the axial movement of the focusing head, and record the main shaft synchronous pulse number; the main shaft synchronous pulse is a zero pulse of a main shaft encoder or a pulse after circumferential reference pulses generated by one or more main shaft encoders are offset.

In this embodiment, the focusing head is stopped after rapidly retreating axially by 0.1 mm.

Specifically, as shown in fig. 2, v1 is the axial constant-speed moving speed of the focusing head, v2 is the maximum axial backward speed of the focusing head, T is the rotation period of the spindle, and n is the number of circumferences corresponding to the short spiral line segment to be engraved and the number of pitches corresponding to the axial constant-speed moving speed of the focusing head. The figure shows that the given time of the two short spirals corresponding to the axial constant-speed movement of the focusing head is (n +1) T (wherein the first T laser is turned off), and the interval time is T. The focusing head is axially retreated by a screw pitch, and the time is less than T.

In this embodiment, n is equal to 200, T is equal to 0.21s, v1 is equal to 0.477mm/s, and 50 segments of short spiral lines are carved together.

In this embodiment, the zero pulse of the spindle encoder activates the electrical signal of the control laser signal, and at the same time, it activates the control focusing head to move axially by 0.477mm/s and starts recording the number of spindle synchronization pulses. The focusing head moves at a constant speed after being axially accelerated.

And step S14, when the number of pulses is the same as the number of the screw pitches, switching the laser according to the preset requirement until the complete short spiral line is engraved.

In this step, before the zero pulse count of the spindle encoder reaches 1, the laser is turned off, and then the output of the laser is controlled according to the required switching information on the corresponding short spiral line until the zero pulse count of the spindle encoder reaches 201, which indicates that the complete short spiral line has been engraved. And turning off the laser after the carving is finished, and stopping the focusing head after the axial direction is decelerated.

In this embodiment, an elongated segment is added at the start position of the short spiral line, and the laser is turned off when the elongated segment of each short spiral line is engraved, where the elongated segment has a circumferential length.

In this step, if all 50 sections of short spiral lines are carved, the main shaft stops rotating, and the whole long spiral line is carved completely. In fig. 3, the meaning of n is the same as that of fig. 2, the diagonal solid straight line is the development diagram of the expected long spiral line, the solid straight line with the head-tail curve is the development diagram of the actual first section of short spiral line, the dotted straight line with the head-tail curve is the development diagram of the actual second section of short spiral line, the section from 1 circumference to 2n +1 circumference which is spliced by two short spiral lines is the actual engraved long spiral line section, and the splicing position is at the n +1 circumference.

If all the 50 short spiral lines are not engraved, the step S12 is executed to sequentially engrave the remaining short spiral lines. The engraving time of the segmented continuous laser engraving method is 1.01 times that of 202 × 50/10000 of the continuous laser engraving method, and is 1% more, and the difference is not great.

In the embodiment, one long spiral line is decomposed into the seamlessly spliced multi-section short spiral line, the synchronous times of the main shaft synchronous pulse to the laser control signal are changed from one time to multiple times, the accumulated deviation is reduced, and the processing precision is improved. In addition, the processing of single short spiral line does not need very big memory, has reduced the requirement to the computer, is convenient for realize the breakpoint reconnection simultaneously, has reduced the loss because of shutting down the cause, has important economic value.