CN102430858A

Movatterモバイル変換

Info

Publication number: CN102430858A
Application number: CN2011103034152A
Authority: CN
Inventors: 段军; 李祥友; 王泽敏; 胡乾午; 曾晓雁
Original assignee: Huazhong University of Science and Technology
Current assignee: Wuhan Flex Laser Technology Co Ltd
Priority date: 2011-10-10
Filing date: 2011-10-10
Publication date: 2012-05-02
Anticipated expiration: 2031-10-10
Also published as: CN102430858B

Abstract

本发明公开了一种激光加工自动调焦装置，该装置包括Z轴移动系统、激光聚焦系统、控制系统和激光位移检测系统，控制系统与Z轴移动系统及激光位移检测系统电连接，激光位移检测系统与激光聚焦系统刚性连接在一起固定在Z轴移动系统上，随Z轴移动系统沿Z轴方向上下移动；控制系统根据激光位移检测系统提供的电信号的符号和幅值控制Z轴移动系统的位移。本发明具有如下优点：不受材料性质的限制，即：金属和非金属均可应用，应用范围广；由于是非接触测量，不受材料表面情况限制，不会损坏材料表面；检测精度高，可达纳米级精度，故可用于纳米级的激光自动调焦高进度应用；结构简单，价格低廉、稳定性好。

The invention discloses an automatic focusing device for laser processing. The device includes a Z-axis moving system, a laser focusing system, a control system and a laser displacement detection system. The control system is electrically connected with the Z-axis movement system and the laser displacement detection system. The laser displacement The detection system and the laser focusing system are rigidly connected and fixed on the Z-axis moving system, and move up and down along the Z-axis direction with the Z-axis moving system; the control system controls the Z-axis movement according to the sign and amplitude of the electrical signal provided by the laser displacement detection system system displacement. The present invention has the following advantages: not limited by material properties, that is: both metal and non-metal can be used, and has a wide range of applications; due to non-contact measurement, it is not limited by the surface of the material and will not damage the surface of the material; the detection accuracy is high and can be Reaching nanometer-level precision, it can be used for high-speed applications of nanometer-level laser auto-focusing; the structure is simple, the price is low, and the stability is good.

Description

Translated fromChinese

一种激光加工自动调焦装置An automatic focusing device for laser processing

技术领域technical field

本发明属于激光加工应用技术领域，具体涉及一种激光加工自动调焦装置。The invention belongs to the technical field of laser processing applications, and in particular relates to an automatic focusing device for laser processing.

背景技术Background technique

在激光加工应用中，用于加工的激光束通过光学聚焦系统将激光束聚焦为较小的光斑，获得极高的功率密度或能量密度使材料被加热、熔化或蒸发，实现所需的加工应用功能(如激光热处理、熔覆、焊接、切割、钻孔和刻蚀等加工应用)。同时，利用激光可聚焦尺寸小的优势来实现高精度尺寸加工。然而，在激光加工过程中，被加工工件自身表面不平和激光加工过程中被加工间受热变形以及聚焦激光束行走轨迹波动都会造成激光焦点位置的偏移。当激光聚焦点位置产生偏移大于焦深时，将会导致激光功率密度或能量密度以及激光光斑尺寸的较大变化(如当激光聚焦点位置偏离材料加工表面时，会导致激光在材料加工表面上的功率密度或能量密度较大下降以及光斑尺寸增加)，其结果会造成激光加工质量和尺寸精度的不一致。为了确保激光加工质量和尺寸的稳定性和一致性，要求激光焦点位置的波动范围应小于激光聚焦焦深范围以内。目前达到以上要求的方法是采用激光加工自动调焦技术，其基本原理是采用一种传感器来检测焦点位置的偏移量，一旦检测到焦点位置偏离原位置，则立即输出信号给控制系统，控制系统调节Z轴移动系统将激光焦点调回到原来位置，实现保持激光焦点位置不变的功能。当前激光加工系统焦点位置的检测多基于接触式传感器或者电容式和电感式传感器。如在“激光切割非接触式高度自动控制装置”(组合机床与自动化加工技术期刊.1992(10).-9-12)文献中采用了电容式传感器检测激光焦点位置。当激光焦点位置发生偏移时，将输出信号给信号处理电路、单片机控制器和伺服驱动系统，调节Z轴移动系统将激光焦点调回到原来位置。但电容式或电感式传感器只能应用于金属工件的激光加工中，不能用于非金属工件的激光加工中，从而限制了应用范围，并且结构复杂，价格较高。而接触式传感器具有精度误差较大和易损坏加工表面覆盖的功能薄膜，并且触头容易磨损影响精度，响应频率不会很高等缺点。In laser processing applications, the laser beam used for processing focuses the laser beam into a smaller spot through an optical focusing system to obtain extremely high power density or energy density so that the material is heated, melted or evaporated to achieve the desired processing application Functions (such as processing applications such as laser heat treatment, cladding, welding, cutting, drilling and etching). At the same time, the advantages of small laser focusable size are used to achieve high-precision dimensional processing. However, in the process of laser processing, the uneven surface of the processed workpiece itself, the thermal deformation of the processed space and the fluctuation of the focused laser beam trajectory will cause the deviation of the laser focus position. When the position of the laser focus point deviates greater than the focal depth, it will cause a large change in the laser power density or energy density and the laser spot size (for example, when the laser focus point position deviates from the material processing surface, it will cause the laser on the material processing surface The power density or energy density on the surface is greatly reduced and the spot size is increased), which will result in inconsistent laser processing quality and dimensional accuracy. In order to ensure the stability and consistency of laser processing quality and size, it is required that the fluctuation range of laser focus position should be smaller than the range of laser focus depth. At present, the method to meet the above requirements is to use laser processing automatic focusing technology. The basic principle is to use a sensor to detect the offset of the focus position. Once the focus position is detected to deviate from the original position, it will immediately output a signal to the control system. System adjustment The Z-axis moving system adjusts the laser focus back to its original position, realizing the function of keeping the laser focus position unchanged. The detection of the focus position of the current laser processing system is mostly based on contact sensors or capacitive and inductive sensors. For example, a capacitive sensor is used to detect the laser focus position in the document "Laser Cutting Non-Contact Height Automatic Control Device" (Journal of Combined Machine Tool and Automatic Processing Technology. 1992 (10).-9-12). When the laser focus position shifts, the output signal is sent to the signal processing circuit, the single-chip controller and the servo drive system, and the Z-axis moving system is adjusted to return the laser focus to the original position. However, capacitive or inductive sensors can only be used in laser processing of metal workpieces, and cannot be used in laser processing of non-metallic workpieces, thus limiting the scope of application, and the structure is complex and the price is high. The contact sensor has the disadvantages of large accuracy error and easy damage to the functional film covered by the processed surface, and the contact is easy to wear and affect the accuracy, and the response frequency is not very high.

发明内容Contents of the invention

为了解决以上问题，本发明提供了一种激光加工自动调焦装置，不但可用于金属工件和非金属工件的激光加工之中，而且具有结构简单、成本低廉和精度高的特点。In order to solve the above problems, the present invention provides an automatic focusing device for laser processing, which can not only be used in laser processing of metal workpieces and non-metal workpieces, but also has the characteristics of simple structure, low cost and high precision.

本发明提供的一种激光加工自动调焦装置，该装置包括Z轴移动系统、激光聚焦系统和控制系统；其特征在于，该装置还包括激光位移检测系统，控制系统与Z轴移动系统及激光位移检测系统电连接，激光位移检测系统与激光聚焦系统刚性连接在一起固定在Z轴移动系统上，随Z轴移动系统沿Z轴方向上下移动；控制系统根据激光位移检测系统提供的电信号的符号和幅值控制Z轴移动系统的位移。The invention provides an automatic focusing device for laser processing, which includes a Z-axis moving system, a laser focusing system and a control system; it is characterized in that the device also includes a laser displacement detection system, a control system, a Z-axis moving system and a The displacement detection system is electrically connected, the laser displacement detection system is rigidly connected with the laser focusing system and fixed on the Z-axis moving system, and moves up and down along the Z-axis direction with the Z-axis moving system; the control system is based on the electrical signal provided by the laser displacement detection system. Sign and magnitude control the displacement of the Z-axis movement system.

本发明的基本原理是采用了激光三角测量原理，由激光位移检测系统的激光器对激光加工工件发射一束检测激光束，工件表面将检测激光束以一定角度反射回到激光位移检测系统的接收端，穿过透镜，聚焦成像在光线收集器(由CCD或CMOS组成的光线收集矩阵)上形成光斑。再通过电荷耦合器件将光线信号传入微处理器，将测量结果以模拟电信号的形式输出。改变激光位移检测系统和激光加工工件表面之间的距离，检测激光束的反射光线夹角和光线收集器上的光斑位置都会随之变化。由于激光线反射后的角度和被测工件的距离成比例，因此，在处理获得角度后，激光位移检测系统通过计算便可得到实际距离的变化值大小。当距离的变化值不为零时；即焦点发生偏移，将通过控制系统来调节Z轴移动系统，消除该变化值，使焦点重新回到原来位置，从而达到自动调焦的目的。如当加工激光聚焦平面在工件表面上时，设定激光位移检测系统将检测激光束反射回到接收端的光线角度产生的输出信号为零，故激光位移检测系统对控制系统输出信号为零，控制系统保持Z轴移动系统不移动。当因某种原因导致激光聚焦平面向下偏离工件表面某一距离时，激光位移检测系统的接收端测得的反射回激光线发生负角度和光线收集器上的光斑位置的变化，通过计算激光线负角度和光线收集器上的光斑位置的变化大小，将输出给控制系统一个相应幅值的负电信号(负电压或电流)，控制系统将根据电信号的符号和幅值来调节Z轴移动系统向上移动相同的某一距离，使加工激光聚焦平面重新回到工件表面上，反之亦然，从而达到激光自动调焦的目的。本发明具有如下优点：The basic principle of the present invention is to adopt the principle of laser triangulation, the laser device of the laser displacement detection system emits a detection laser beam to the laser processing workpiece, and the surface of the workpiece reflects the detection laser beam back to the receiving end of the laser displacement detection system at a certain angle , pass through the lens, and focus the image to form a spot on the light collector (a light collection matrix composed of CCD or CMOS). Then the optical signal is transmitted to the microprocessor through the charge-coupled device, and the measurement result is output in the form of an analog electrical signal. Changing the distance between the laser displacement detection system and the surface of the laser processed workpiece, the included angle of the reflected light of the detection laser beam and the spot position on the light collector will change accordingly. Since the reflected angle of the laser line is proportional to the distance of the measured workpiece, the laser displacement detection system can obtain the change value of the actual distance through calculation after processing the obtained angle. When the change value of the distance is not zero; that is, the focus shifts, the Z-axis movement system will be adjusted through the control system to eliminate the change value, and the focus will return to the original position, so as to achieve the purpose of automatic focusing. For example, when the focus plane of the processing laser is on the surface of the workpiece, the output signal generated by the laser displacement detection system reflecting the detection laser beam back to the light angle at the receiving end is zero, so the output signal of the laser displacement detection system to the control system is zero, and the control The system keeps the Z axis moving and the system does not move. When the laser focus plane deviates downward from the surface of the workpiece by a certain distance for some reason, the reflected laser line measured by the receiving end of the laser displacement detection system has a negative angle and a change in the spot position on the light collector. The negative angle of the line and the change size of the spot position on the light collector will output a negative electrical signal (negative voltage or current) of corresponding amplitude to the control system, and the control system will adjust the Z-axis movement according to the sign and amplitude of the electrical signal The system moves up the same certain distance, so that the processing laser focus plane returns to the surface of the workpiece, and vice versa, so as to achieve the purpose of laser automatic focus. The present invention has the following advantages:

1.不受材料性质的限制，即：金属和非金属均可应用，应用范围广；1. It is not limited by the nature of the material, that is, both metal and non-metal can be applied, and the application range is wide;

2.由于是非接触测量，不受材料表面情况限制，不会损坏材料表面；2. Since it is a non-contact measurement, it is not limited by the surface condition of the material and will not damage the surface of the material;

3.检测精度高，可达纳米级精度，故可用于纳米级的激光自动调焦高进度应用；3. High detection accuracy, up to nano-level precision, so it can be used for high-speed applications of nano-level laser auto-focusing;

4.结构简单，价格低廉、稳定性好。4. Simple structure, low price and good stability.

附图说明Description of drawings

图1为激光加工自动调焦一种具体实施方式的结构示意图；Fig. 1 is a structural schematic diagram of a specific embodiment of automatic focusing in laser processing;

图2为加工激光焦点向下偏移时，检测激光束检测光线的反射光线夹角和聚焦成像在光线收集器的变化；Fig. 2 shows the change of the included angle of the reflected light of the detection laser beam and the focus image in the light collector when the focus of the processing laser is shifted downward;

图3为加工激光焦点向上偏移时，检测激光束检测光线的反射光线夹角和聚焦成像在光线收集器的变化。Fig. 3 shows the change of the included angle of the reflected light of the detection laser beam and the focused image in the light collector when the focus of the processing laser is shifted upward.

图4为激光加工自动调焦第二种具体实施方式的结构示意图；Fig. 4 is a structural schematic diagram of a second embodiment of laser processing automatic focusing;

图5为加工激光焦点向下偏移时，检测激光束检测光线的反射光线夹角和聚焦成像在光线收集器的变化的示意图；Fig. 5 is a schematic diagram of the change of the reflected light angle of the detection laser beam detection light and the change of the focused image in the light collector when the focus of the processing laser is shifted downward;

图6为加工激光焦点向上偏移时，检测激光束检测光线的反射光线夹角和聚焦成像在光线收集器的变化的示意图。Fig. 6 is a schematic diagram of the change of the included angle of the reflected light of the detection laser beam and the focused image in the light collector when the focus of the processing laser is shifted upward.

具体实施方式Detailed ways

下面通过附图和实例对本发明方法作进一步详细的说明。The method of the present invention will be described in further detail below by means of accompanying drawings and examples.

实现上述方法的装置之一，如图1所示，本发明装置包括Z轴移动系统1、激光聚焦系统3、激光位移检测系统7和控制系统9。As one of the devices for realizing the above method, as shown in FIG. 1 , the device of the present invention includes a Z-axis movingsystem 1 , alaser focusing system 3 , a laser displacement detection system 7 and acontrol system 9 .

激光位移检测系统7包括激光器10、透镜12和光线收集器11，透镜12和光线收集器11依次位于激光器10发射的激光束在工件表面上产生反射光的可视范围内。激光器10所发射的检测激光束5的功率以不破坏平面工件8为限，通常只有几瓦、几毫瓦甚至几个微瓦。The laser displacement detection system 7 includes alaser 10 , alens 12 and alight collector 11 . Thelens 12 and thelight collector 11 are sequentially located within the visible range where the laser beam emitted by thelaser 10 produces reflected light on the workpiece surface. The power of thedetection laser beam 5 emitted by thelaser 10 is limited not to damage theplanar workpiece 8, usually only a few watts, a few milliwatts or even a few microwatts.

激光位移检测系统7与激光聚焦系统3刚性连接在一起固定在Z轴移动系统1上，随Z轴移动系统1沿Z轴方向上下移动。加工激光束2经激光聚焦系统3聚焦后形成聚焦激光束4，并聚焦在被加工平面工件8的表面上。激光位移检测系统7中的激光器10对激光加工平面工件8发射一束检测激光束5，平面工件8的表面将检测激光束5以α₀角度反射，形成激光束6反射回到激光位移检测系统7的接收端，穿过透镜12，聚焦成像在光线收集器11(由CCD或CMOS组成的光线收集器)的a处上形成光斑。设定聚焦激光束4聚焦在被加工平面工件8的表面时，激光位移检测系统7的检测激光束5反射回到接收端激光束6所产生角度和位置的输出信号为零，此时激光位移检测系统7对控制系统输出信号为零，控制系统9保持Z轴移动系统1不移动。The laser displacement detection system 7 is rigidly connected with thelaser focusing system 3 and fixed on the Z-axis movingsystem 1 , and moves up and down along the Z-axis direction with the Z-axis moving system 1 . Theprocessing laser beam 2 is focused by thelaser focusing system 3 to form a focusedlaser beam 4, which is then focused on the surface of theworkpiece 8 to be processed. Thelaser 10 in the laser displacement detection system 7 emits adetection laser beam 5 to the laserprocessing plane workpiece 8, and the surface of theplane workpiece 8 reflects thedetection laser beam 5 at an angle of α₀ to form alaser beam 6 reflected back to the laser displacement detection system The receiving end of 7 passes through thelens 12 and is focused and imaged to form a light spot at a of the light collector 11 (a light collector composed of CCD or CMOS). When the focusedlaser beam 4 is set to focus on the surface of the processedplane workpiece 8, the output signal of the angle and position generated by thedetection laser beam 5 of the laser displacement detection system 7 reflected back to the receivingend laser beam 6 is zero, and the laser displacement The output signal of the detection system 7 to the control system is zero, and thecontrol system 9 keeps the Z-axis movingsystem 1 from moving.

实例1：Example 1:

当因某种原因使加工激光聚焦点4向下偏离工件8表面h₁距离时(如图2所示)，激光位移检测系统和工件表面之间的距离变短，反射激光线6与检测激光束5之间的夹角增加为α₁，并穿过透镜12聚焦成像在光线收集器上的光斑位置从a处向下移动到e处。此时激光位移检测系统7将向控制系统9输出一定幅值的负电压或电流信号，幅值的大小与工激光聚焦点4的偏移距离大小呈线性比例。控制系统9根据激光位移检测系统7输入信号的符号和幅值大小调节Z轴移动系统1向上移动，激光位移检测系统和工件表面之间的距离也同时增加。当Z轴移动系统1向上移动相同的h₁距离时，加工激光聚焦点4重新回到工件8表面上，反射激光线6与检测激光束5之间的夹角也重新回到α₀，并穿过透镜12聚焦成像在光线收集器上的光斑位置从e处向上移动到a处，此时激光位移检测系统7对控制系统输出信号为零，控制系统9将停止Z轴移动系统1移动，完成激光自动调节过程。When the processinglaser focus point 4 deviates downward from the surface of theworkpiece 8 by h₁ for some reason (as shown in Figure 2), the distance between the laser displacement detection system and the surface of the workpiece becomes shorter, and thereflected laser line 6 and the detection laser The angle between thebeams 5 increases to α₁ , and the position of the light spot that passes through thelens 12 and is focused and imaged on the light collector moves downward from a to e. At this time, the laser displacement detection system 7 will output a negative voltage or current signal with a certain amplitude to thecontrol system 9, and the amplitude is linearly proportional to the offset distance of the industriallaser focus point 4 . Thecontrol system 9 adjusts the Z-axis movingsystem 1 to move upward according to the sign and amplitude of the input signal of the laser displacement detection system 7, and the distance between the laser displacement detection system and the workpiece surface also increases simultaneously. When the Z-axis movingsystem 1 moves upwards by the same h₁ distance, the processinglaser focus point 4 returns to the surface of theworkpiece 8, and the angle between thereflected laser line 6 and thedetection laser beam 5 also returns to α₀ , and The position of the light spot focused and imaged on the light collector through thelens 12 moves upward from e to a. At this time, the output signal of the laser displacement detection system 7 to the control system is zero, and thecontrol system 9 will stop the movement of the Z-axis moving system 1. Complete the laser auto-adjustment process.

实例2：Example 2:

当因某种原因使加工激光聚焦点4向上偏离工件8表面h₂距离时(如图3所示)，激光位移检测系统和工件表面之间的距离变长，反射激光线6与检测激光束5之间的夹角减小为α₂，并穿过透镜12聚焦成像在光线收集器上的光斑位置从a处向下移动到f处，此时激光位移检测系统7将向控制系统9输出一定幅值的正电压或电流信号，幅值的大小与工激光聚焦点4的偏移距离大小呈线性比例。控制系统9根据激光位移检测系统7输入信号的符号和幅值大小调节Z轴移动系统1向下移动，激光位移检测系统和工件表面之间的距离也同时减小。当Z轴移动系统1向下移动相同的h₂距离时，加工激光聚焦点4重新回到工件8表面上，反射激光线6与检测激光束5之间的夹角也重新回到α₀，并穿过透镜12聚焦成像在光线收集器上的光斑位置从f处向上移动到a处，此时激光位移检测系统7对控制系统输出信号为零，控制系统9将停止Z轴移动系统1移动，完成激光自动调节过程。When the processinglaser focus point 4 deviates upwards from the surface of theworkpiece 8 by a distance of_h2 for some reason (as shown in Figure 3), the distance between the laser displacement detection system and the surface of the workpiece becomes longer, and the reflectedlaser line 6 and the detection laser beam The included angle between 5 is reduced to α₂ , and the position of the light spot that is focused and imaged on the light collector through thelens 12 moves downward from a to f, at this time the laser displacement detection system 7 will output to thecontrol system 9 For a positive voltage or current signal with a certain amplitude, the amplitude is linearly proportional to the offset distance of the industriallaser focus point 4 . Thecontrol system 9 adjusts the Z-axis moving system 1 to move downward according to the sign and amplitude of the input signal of the laser displacement detection system 7, and the distance between the laser displacement detection system and the workpiece surface also decreases at the same time. When the Z-axis moving system 1 moves downward by the same_h2 distance, the processinglaser focus point 4 returns to the surface of theworkpiece 8, and the angle between thereflected laser line 6 and thedetection laser beam 5 also returns to α₀ , And pass through thelens 12 to focus and image the spot on the light collector and move upward from f to a. At this time, the output signal of the laser displacement detection system 7 to the control system is zero, and thecontrol system 9 will stop the movement of the Z-axis movement system 1 , to complete the laser automatic adjustment process.

实现上述方法的装置之二，如图4所示，用于激光曲面加工情况下的自动调焦方法及装置。由Z轴移动系统1、激光聚焦系统3、激光位移检测系统7和控制系统9组成。激光位移检测系统7与激光聚焦系统3刚性连接在一起固定在Z轴移动系统1上，随Z轴移动系统1沿Z轴方向上下移动。加工激光束2经激光聚焦系统3聚焦后形成聚焦激光束4，并聚焦在被加工曲面工件15的表面上。激光位移检测系统7中的激光器10对激光加工曲面工件15发射一束检测激光束5，与聚焦激光束4之间的夹角θ不大于40°，在激光加工曲面工件15上与聚焦激光束4焦点的空间位置重合，确保精确的测量激光焦点的偏移量。曲面工件15表面将检测激光束5以δ₀角度反射，形成激光束6反射回到激光位移检测系统7的接收端，穿过透镜12，聚焦成像在光线收集器11(由CCD或CMOS组成的光线收集器)的a处上形成光斑。设定聚焦激光束4聚焦在被加工曲面工件15的表面时，激光位移检测系统7的检测激光束5反射回到接收端激光束6所产生角度和位置的输出信号为零，此时激光位移检测系统7对控制系统输出信号为零，控制系统9保持Z轴移动系统1不移动。The second device for realizing the above method, as shown in FIG. 4 , is used for an automatic focusing method and device in the case of laser curved surface processing. It consists of a Z-axis moving system 1, alaser focusing system 3, a laser displacement detection system 7 and acontrol system 9. The laser displacement detection system 7 is rigidly connected with thelaser focusing system 3 and fixed on the Z-axis moving system 1 , and moves up and down along the Z-axis direction with the Z-axis moving system 1 . Theprocessing laser beam 2 is focused by thelaser focusing system 3 to form afocused laser beam 4 , which is then focused on the surface of thecurved workpiece 15 to be processed. Thelaser 10 in the laser displacement detection system 7 emits adetection laser beam 5 to the laser-processedcurved surface workpiece 15, and the included angle θ with thefocused laser beam 4 is not greater than 40°. The spatial positions of the 4 focal points coincide to ensure accurate measurement of the offset of the laser focus. The surface of thecurved workpiece 15 reflects thedetection laser beam 5 at an angle of_δ0 , forming thelaser beam 6 to reflect back to the receiving end of the laser displacement detection system 7, pass through thelens 12, and focus and image it on the light collector 11 (made up of CCD or CMOS) A light spot is formed at a of the light collector). When thefocused laser beam 4 is set to focus on the surface of the processedcurved workpiece 15, the output signal of the angle and position generated by thedetection laser beam 5 of the laser displacement detection system 7 reflected back to the receivingend laser beam 6 is zero, and the laser displacement The output signal of the detection system 7 to the control system is zero, and thecontrol system 9 keeps the Z-axis moving system 1 from moving.

实例3：Example 3:

当因某种原因使加工激光聚焦点4向下偏离曲面工件9表面h₃距离时(如图5所示)，激光位移检测系统和工件表面之间的距离变短，反射激光线6与检测激光束5之间的夹角增加为δ₁，并穿过透镜12聚焦成像在光线收集器上的光斑位置从a处向下移动到d处。此时激光位移检测系统7将向控制系统9输出一定幅值的负电压或电流信号，幅值的大小与工激光聚焦点4的偏移距离大小呈线性比例。控制系统9根据激光位移检测系统7输入信号的符号和幅值大小调节Z轴移动系统1向上移动，激光位移检测系统和工件表面之间的距离也同时增加。当Z轴移动系统1向上移动相同的h₃距离时，加工激光聚焦点4重新回到曲面工件15表面上，反射激光线6与检测激光束5之间的夹角也重新回到δ₀，并穿过透镜12聚焦成像在光线收集器上的光斑位置从d处向上移动到a处，此时激光位移检测系统7对控制系统输出信号为零，控制系统9将停止Z轴移动系统1移动，完成激光自动调节过程。When the processinglaser focus point 4 deviates downward from the surface of thecurved workpiece 9 by a distance of_h3 for some reason (as shown in Figure 5), the distance between the laser displacement detection system and the surface of the workpiece becomes shorter, and the reflectedlaser line 6 and the detection The included angle between thelaser beams 5 is increased to δ₁ , and the position of the spot focused on the light collector after passing through thelens 12 moves downward from a to d. At this time, the laser displacement detection system 7 will output a negative voltage or current signal with a certain amplitude to thecontrol system 9, and the amplitude is linearly proportional to the offset distance of the industriallaser focus point 4 . Thecontrol system 9 adjusts the Z-axis moving system 1 to move upward according to the sign and amplitude of the input signal of the laser displacement detection system 7, and the distance between the laser displacement detection system and the workpiece surface also increases simultaneously. When the Z-axis moving system 1 moves upward for the same_h3 distance, the processinglaser focus point 4 returns to the surface of thecurved workpiece 15, and the angle between thereflected laser line 6 and thedetection laser beam 5 also returns to δ₀ , And pass through thelens 12 to focus and image the spot on the light collector and move upward from d to a. At this time, the output signal of the laser displacement detection system 7 to the control system is zero, and thecontrol system 9 will stop the movement of the Z-axis moving system 1 , to complete the laser automatic adjustment process.

实例4：Example 4:

当因某种原因使加工激光聚焦点4向上偏离曲面工件15表面h4距离时(如图6所示)，激光位移检测系统和工件表面之间的距离变长，反射激光线6与检测激光束5之间的夹角减小为δ₂，并穿过透镜12聚焦成像在光线收集器上的光斑位置从a处向下移动到g处，此时激光位移检测系统7将向控制系统9输出一定幅值的正电压或电流信号，幅值的大小与工激光聚焦点4的偏移距离大小呈线性比例。控制系统9根据激光位移检测系统7输入信号的符号和幅值大小调节Z轴移动系统1向下移动，激光位移检测系统和工件表面之间的距离也同时减小。当Z轴移动系统1向下移动相同的h₂距离时，加工激光聚焦点4重新回到曲面工件15表面上，反射激光线6与检测激光束5之间的夹角也重新回到δ₀，并穿过透镜12聚焦成像在光线收集器上的光斑位置从g处向上移动到a处，此时激光位移检测系统7对控制系统输出信号为零，控制系统9将停止Z轴移动系统1移动，完成激光自动调节过程。When the processinglaser focus point 4 deviates from the surface h4 of thecurved surface workpiece 15 for some reason (as shown in Figure 6), the distance between the laser displacement detection system and the workpiece surface becomes longer, and the reflectedlaser line 6 and the detection laser beam The included angle between 5 is reduced to δ₂ , and the position of the light spot that is focused and imaged on the light collector through thelens 12 moves downward from a to g, at this time the laser displacement detection system 7 will output to thecontrol system 9 For a positive voltage or current signal with a certain amplitude, the amplitude is linearly proportional to the offset distance of the industriallaser focus point 4 . Thecontrol system 9 adjusts the Z-axis moving system 1 to move downward according to the sign and amplitude of the input signal of the laser displacement detection system 7, and the distance between the laser displacement detection system and the workpiece surface also decreases at the same time. When the Z-axis moving system 1 moves downward by the same_h2 distance, the processinglaser focus point 4 returns to the surface of thecurved workpiece 15, and the angle between thereflected laser line 6 and thedetection laser beam 5 also returns to_δ0 , and pass through thelens 12 to focus and image the spot on the light collector and move upward from g to a. At this time, the output signal of the laser displacement detection system 7 to the control system is zero, and thecontrol system 9 will stop the Z-axis movement system 1 Move to complete the laser automatic adjustment process.

本发明不仅局限于上述具体实施方式，本领域一般技术人员根据本发明公开的内容，可以采用其它多种具体实施方式实施本发明，因此，凡是采用本发明的技术方案和思路，做一些简单的变化或更改，都落入本发明保护的范围。The present invention is not limited to the above-mentioned specific embodiments, and those skilled in the art can adopt various other specific embodiments to implement the present invention according to the disclosed content of the present invention. Changes or modifications all fall within the protection scope of the present invention.

Claims

Translated fromChinese

1.一种激光加工自动调焦装置，该装置包括Z轴移动系统(1)、激光聚焦系统(3)和控制系统(9)；其特征在于，该装置还包括激光位移检测系统(7)，控制系统(9)与Z轴移动系统(1)及激光位移检测系统(7)电连接，激光位移检测系统7与激光聚焦系统(3)刚性连接在一起固定在Z轴移动系统(1)上，随Z轴移动系统(1)沿Z轴方向上下移动；控制系统(9)根据激光位移检测系统(7)提供的电信号的符号和幅值控制Z轴移动系统(1)的位移。1. An automatic focusing device for laser processing, the device includes a Z-axis moving system (1), a laser focusing system (3) and a control system (9); it is characterized in that the device also includes a laser displacement detection system (7) , the control system (9) is electrically connected with the Z-axis moving system (1) and the laser displacement detection system (7), and the laser displacement detection system 7 is rigidly connected with the laser focusing system (3) and fixed on the Z-axis movement system (1) On the top, the Z-axis moving system (1) moves up and down along the Z-axis direction; the control system (9) controls the displacement of the Z-axis moving system (1) according to the sign and amplitude of the electrical signal provided by the laser displacement detection system (7).

2.根据权利要求1所述的激光加工自动调焦装置，其特征在于，所述激光位移检测系统(7)包括激光器(10)、透镜(12)和光线收集器(11)，透镜(12)和光线收集器(11)依次位于激光器(10)发射的激光束在工件表面上产生反射光的可视范围内，激光器(10)发射的检测激光束经工作反射后，再经透镜(12)进入光线收集器(11)。2. The laser processing automatic focusing device according to claim 1, characterized in that, the laser displacement detection system (7) comprises a laser (10), a lens (12) and a light collector (11), and the lens (12 ) and the light collector (11) are sequentially located in the visible range where the laser beam emitted by the laser (10) generates reflected light on the surface of the workpiece. After the detection laser beam emitted by the laser (10) is reflected by the work, it passes through the lens (12 ) into the light collector (11).

3.根据权利要求2所述的激光加工自动调焦装置，其特征在于，激光器(10)发射的检测激光束(5)与聚焦激光束(4)平行。3. The laser processing automatic focusing device according to claim 2, characterized in that the detection laser beam (5) emitted by the laser (10) is parallel to the focused laser beam (4).

4.根据权利要求2所述的激光加工自动调焦装置，其特征在于，激光器(10)发射的检测激光束(5)与聚焦激光束(4)之间的夹角小于等于40度。4. The automatic focusing device for laser processing according to claim 2, characterized in that the angle between the detection laser beam (5) emitted by the laser (10) and the focused laser beam (4) is less than or equal to 40 degrees.