CN114160964B - Double-pendulum-axis zero calibration method for laser processing - Google Patents

Abstract

The invention provides a double-pendulum-axis zero calibration method for laser processing, which mainly solves the problem that the existing calibration method is not suitable for double-pendulum-axis zero calibration of a five-axis linkage laser processing machine tool, so that the processing precision is low. The method of the invention can etch on a transparent material flat plate through laser beams by combining the motion of two motors of the double-swing-axis laser processing head with the focus focused after output, and can obtain the zero point position of the double-swing-axis motor by measuring the distance of etched laser spots. The device required by the method is simple in structure, can quickly and accurately obtain the zero coordinates of the A axis and the C axis, and is very suitable for high-precision calibration of the zero positions of the double swing axes in laser processing equipment.

Description

A zero-point calibration method of double pendulum axes for laser processing

technical field

The invention belongs to the field of laser processing, and in particular relates to a zero point calibration method of double pendulum shafts for laser processing.

Background technique

Laser processing is to irradiate the laser beam to the surface of the workpiece, and use high energy density laser to cut, melt the material and change the surface properties of the object. At present, laser processing has been widely used in aviation, aerospace, navigation, automobile, semiconductor and other industries, and the five-axis linkage laser processing machine tool is the equipment with high processing accuracy.

During the debugging process of the five-axis linkage laser processing machine tool, the coincidence accuracy of the rotation axis of the double pendulum axis and the X/Y/Z coordinate system of the machine tool determines the machining accuracy of the five-axis machine tool. In addition, when the machine tool is outputting the processing program through the post-processing software, the rotation axes of the two motors of the double pendulum axis are set in the post-processing software to completely coincide with the two axes of the linear axis respectively. If it is accurate, the coordinates of the output processing program will have deviations, which will affect the processing accuracy. Finally, the zero-point calibration accuracy of the double pendulum axis is the basis for the RTCP calibration accuracy of the five-axis machine tool. Only when a high-precision five-axis coordinate system is established in the machine tool coordinate system can high-precision five-axis machining be realized. Chinese patent CN2018106993942 discloses a RTCP accuracy compensation method for five-axis laser processing equipment, which can realize RTCP accuracy compensation for laser processing machine tools, but does not explain the zero point calibration method of the double pendulum axis. The zero point calibration of the double pendulum axis in traditional machining can be realized by the dial gauge measurement method, however, this method is not suitable for the double pendulum axis of laser processing equipment.

Contents of the invention

The purpose of the present invention is to solve the problem that the existing method is not suitable for the zero point calibration of the double pendulum axis of the five-axis linkage laser processing machine tool, so that the processing accuracy is low, and to provide a method for the zero point calibration of the double pendulum axis for laser processing.

To achieve the above object, the present invention adopts the following technical solutions:

The zero point calibration method of double pendulum axes for laser processing of the present invention comprises the following steps:

Step 1. Install a distance measuring sensor on the head of the double pendulum laser processing head, calibrate the position of the distance measuring sensor and the laser focus, and the value of the distance measuring sensor after calibration is J1;

Step 2. When the selected double pendulum shaft is an absolute value motor, before calibrating the zero value, adjust the angle of the C-axis motor and the A-axis motor by visual inspection, so that the rotation axis of the A-axis driven by the C-axis motor is roughly the same as that of the A-axis. The X-axis movement direction of the machine tool is parallel, so that the head of the double-swing-axis laser processing head is roughly parallel to the Y-axis movement direction of the machine tool. Record the coordinates A1 and C1 of the A-axis and C-axis at this time to obtain the initial zero point of the double-swing-axis laser processing head Position, which is used as the reference zero point of the machine tool coordinate system;

Step 3. Adjust the A-axis motor and C-axis motor to the initial zero position, place a transparent material plate with a thickness of t at the laser focus position, adjust the position of the transparent material plate so that the plane of the transparent material plate is parallel to the XZ plane, and at the same time , so that the value of the ranging sensor remains at J1;

Step 4: Turn on the laser, etch two lines along the X and Z directions on the front of the transparent material plate; in addition, turn on the laser for several milliseconds to form a spot 1 with a diameter of about 0.01mm on the front of the transparent material plate, and record Y at this time Axial coordinate Y1; in this step, the two etched lines are used to measure the distance components of the laser spot in the X and Z directions in subsequent steps;

Step 5. Keep the C-axis at 0 degrees, rotate the A-axis 180°, move the Y-axis of the machine tool, adjust the position of the double-swing laser processing head through the ranging sensor, make the laser focus fall on the back of the transparent material plate, and fine-tune the Y-axis. Make the value of the ranging sensor display as J1, turn on the laser for several milliseconds, etch a spot 2 of 0.01mm on the back of the transparent material plate, record the Y-axis coordinate Y2 at this time, and the rotation radius of the double-oscillating-axis laser processing head is D=( ∣Y1-Y2∣-t)/2;

Step 6. Take out the transparent material plate, measure the distance between spot 1 and spot 2 under the microscope, and calculate the distance difference between the two spots. If the distance difference between the two spots is less than the set value, then obtain the A-axis and For the coordinates A0 and C0 of the C axis, go to step 9; if the distance difference between the two spots is greater than the set value, go to step 7;

Step 7. Measure the distance between spot 1 and spot 2 under the microscope. Based on the two lines etched in step 4, obtain the distance dx and dy of the two spots in the X direction and Z direction, and then obtain the A axis and C axis The adjustment angle Ta=arctan (dz/2D) and the adjustment angle Tc=arctan (dx/2D);

Step 8. According to the adjustment angle Ta and the adjustment angle Tc obtained in step 7, adjust the angles of the A-axis and the C-axis respectively; then repeat steps 3 to 6, so as to repeatedly measure and adjust the angles of the A-axis and C-axis until there are two spots The distance difference is less than the set value;

Step 9: Just use A0 and C0 as the zero point coordinates of the CNC system.

Further, in step 1, the ranging sensor is a coaxial ranging sensor or a side-axis ranging sensor.

Compared with the prior art, the present invention has the following beneficial effects:

1. The method of the present invention carries out etching on the transparent material plate (such as acrylic plate) through the movement of the two motors of the double pendulum axis and the focal point after combining the output, and by measuring the distance of the laser spot of the etching, you can get The zero position of the double pendulum motor with high precision.

2. The device required by the method of the present invention is simple in structure, and can quickly and accurately obtain the zero point position of the machine tool coordinate system of the double swing head, which is very suitable for the alignment of the zero point coordinate system of the machine tool of the double swing axis laser processing head in laser processing equipment.

Description of drawings

Fig. 1 is a schematic diagram of a dual-swing laser processing head of an existing five-axis linkage laser processing machine tool;

Fig. 2 is a schematic diagram of spots on the surface of a transparent material flat plate in the method of the present invention.

Reference signs: 1-laser beam, 2-C-axis motor, 3-mirror 1, 4-A-axis motor, 5-mirror 2, 6-range sensor, 7-transparent material plate.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention, and are not intended to limit the protection scope of the present invention.

The invention provides a zero point calibration method of double pendulum shafts for laser processing, which is used to solve the problem of zero point calibration of double pendulum shafts in existing laser processing equipment. In the method of the present invention, through the movement of the two motors of the double pendulum shafts, combined with the focal point after the output, the laser beam 1 is used to etch on a transparent material flat plate (such as an acrylic plate), and by measuring the laser spot distance of the etching, the Get the zero position of the double pendulum motor. The device required by the method has a simple structure, can quickly and accurately obtain the zero point coordinates of the A-axis and the C-axis, and is very suitable for high-precision calibration of the zero point positions of the double pendulum axes in laser processing equipment.

As shown in Figure 1, the double-swing-axis laser processing head of the existing five-axis linkage laser processing machine tool includes a C-axis motor 2, a reflector 3, an A-axis motor 4, and a reflector 2 5; The transparent material slab 7 is used as a measurement tool for the laser focus, and a range sensor 6 is installed on the head of the double-swing laser processing head to measure the distance between the double-swing laser processing head and the transparent material slab 7. Through the distance sensor 6 The calibration of the laser focus position can be completed to ensure that the focus position is consistent when the front and back sides of the transparent material plate 7 are etched. At the same time, the space posture of the transparent material plate 7 can be adjusted through the ranging sensor 6 so that it is parallel to the XZ plane of the machine tool. The method of the present invention is described below by specific numerical examples, and the method includes the following processes:

Step 1. Install a distance measuring sensor on the head of the double pendulum laser processing head, then obtain the position of the laser focus, and calibrate the distance between the laser focus and the distance measuring sensor. The value of the calibrated distance measuring sensor is J1;

In this step, a transparent material plate can be used to calibrate the position of the ranging sensor, that is, a transparent material plate is placed at the laser focus, so that the laser focus falls on the surface of the transparent material plate on both sides of the transparent material plate. After calibration The value of the ranging sensor is J1;

Step 2. Adjust the zero point position of the double pendulum axis laser processing head through visual observation, and use this position as the reference zero point of the machine tool coordinate system;

Step 3. Select a transparent material plate with a length of 50mm and a thickness of 1mm as the measurement tool for the laser focus, adjust the A-axis motor and the C-axis motor to their zero positions, and adjust the spatial position of the transparent material plate so that the laser focus is exactly on the The surface of the transparent material flat plate; at the same time, use the ranging sensor to adjust the attitude of the transparent material flat plate, so that the transparent material flat plate is parallel to the XZ plane of the machine tool, and the value of the ranging sensor is kept at J1;

Step 4. Keep the laser always on, and etch a white line with a width of 0.1mm along the X direction and Z direction on the front of the transparent material plate; turn on the laser for 0.1s, adjust the laser power to about 0.2W, and form on the surface of the transparent material plate Mark the white spot with a diameter of about 0.01mm and record it as spot 1, and record the Y-axis coordinate Y1 at the same time;

Step 5: Keep the C-axis at 0 degrees, rotate the A-axis by 180°, move the Y-axis of the machine tool, and adjust the position of the dual-axis laser processing head through the ranging sensor so that the laser focus falls on the back of the transparent material plate; turn on the laser for 0.1s , the laser power is adjusted to about 0.2W, and a white spot with a diameter of about 0.01 is formed on the back of the transparent material plate. Mark it and record it as spot 2. At the same time, record the Y-axis coordinate Y2 at this time, and the rotation radius of the processing head D=(∣Y1 -Y2∣-t)/2; at this time, t is 1mm, that is, D=(∣Y1-Y2∣-1)/2;

Step 6. Take out the transparent material plate, measure the distance between spot 1 and spot 2 under the microscope, and calculate the distance difference between the two spots. If the distance difference between the two spots is less than the set value, then obtain the A-axis and For the coordinates A0 and C0 of the C axis, go to step 9; if the distance difference between the two spots is greater than the set value, go to step 7;

Step 7, as shown in Figure 2, measure the distance between spot 1 and spot 2 under a microscope, and take the two lines etched in step 4 as a benchmark to obtain the distance dx and dy of the two spots in the X direction and Z direction, and then calculate Get the adjustment angle Ta=arctan(dz/2D) and the adjustment angle Tc=arctan(dx/2D) of the A-axis and the C-axis;

Step 8. According to the adjustment angle Ta and the adjustment angle Tc obtained in step 7, adjust the angles of A-axis and C-axis respectively, repeat steps 3 to 6, and measure and adjust the angles of A-axis and C-axis repeatedly until the two spots The distance difference is less than 10 microns;

Step 9: Set A0 and C0 as the zero point coordinates of the CNC system.

Claims (6)

1. A kind of laser processing is characterized in that, comprises the following steps: Step 1. Install a distance measuring sensor on the head of the double pendulum laser processing head, calibrate the position of the distance measuring sensor and the laser focus, and the value of the distance measuring sensor after calibration is J1; Step 2. Adjust the angle of the C-axis motor and the A-axis motor through visual observation, so that the rotation axis of the A-axis driven by the C-axis motor is parallel to the movement direction of the X-axis of the machine tool, so that the head of the double-axis laser processing head is in line with the Y-axis of the machine tool. The axis movement direction is parallel, record the coordinates A1 and C1 of the A axis and the C axis at this time, and obtain the initial zero point position of the double pendulum axis laser processing head, and use this position as the reference zero point of the machine tool coordinate system; Step 3. Adjust the A-axis motor and C-axis motor to the initial zero position, place a transparent material plate with a thickness of t at the laser focus position, adjust the position of the transparent material plate so that the plane of the transparent material plate is parallel to the XZ plane, and at the same time , so that the value of the ranging sensor remains at J1; Step 4: Turn on the laser, etch two lines along the X and Z directions on the front of the transparent material plate, and then turn on the laser for several milliseconds to form a spot 1 on the front of the transparent material plate, and record the Y-axis coordinate Y1 at this time; Step 5. Keep the C-axis at 0 degrees, rotate the A-axis 180°, move the Y-axis of the machine tool, adjust the position of the double-swing laser processing head through the ranging sensor, make the laser focus fall on the back of the transparent material plate, and fine-tune the Y-axis. Make the value of the ranging sensor display as J1, turn on the laser for several milliseconds, etch a spot 2 on the back of the transparent material plate, record the Y-axis coordinate Y2 at this time, and the rotation radius of the double-oscillating-axis laser processing head is D=(∣Y1- Y2∣-t)/2; Step 6. Take out the transparent material plate and measure the distance between spot 1 and spot 2 under the microscope to obtain the zero point position of the double pendulum motor, and calculate the distance difference between the two spots. If the distance difference between the two spots is less than Set the value, then obtain the coordinates A0 and C0 of the A-axis and C-axis at this time, and perform step 9; if the distance difference between the two spots is greater than the set value, then perform step 7; Step 7. Measure the distance between spot 1 and spot 2 under the microscope. Based on the two lines etched in step 4, obtain the distance dx and dy of the two spots in the X direction and Z direction, and then obtain the A axis and C Shaft adjustment angle Ta=arctan(dz/2D) and adjustment angle Tc=arctan(dx/2D); Step 8. Adjust the angles of the A-axis and the C-axis according to the adjustment angle Ta and the adjustment angle Tc obtained in step 7; repeat steps 3 to 6 until the distance difference between the two spots is less than the set value; Step 9: Set A0 and C0 as the zero coordinates of the CNC system. 2. The zero point calibration method of double pendulum axes for laser processing according to claim 1, characterized in that: in step 1, the distance measuring sensor is a coaxial distance measuring sensor or a paraxial distance measuring sensor. 3 . The zero point calibration method with double pendulum axes for laser processing according to claim 1 , wherein in step 3, the transparent material flat plate is an acrylic plate. 4 . 4. The zero-point calibration method with double pendulum axes for laser processing according to claim 1, characterized in that: in step 3, the length and width of the transparent material flat plate are respectively 50 mm, and the thickness is 1 mm. 5. The zero point calibration method with double pendulum axes for laser processing according to claim 1, characterized in that: in step 6, the distance between the two spots is set to 10 microns. 6 . The zero point calibration method with double pendulum axes for laser processing according to claim 1 , wherein in step 4, the diameter of spot 1 is 0.01 mm, and in step 5, the diameter of spot 2 is 0.01 mm.

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