High-precision five-axis laser drilling device and method

Abstract

The invention discloses a high-precision five-axis laser drilling device and method. The device comprises a light beam dip angle adjusting system, a focus height adjusting system, a focus position adjusting system, a focusing optical element and a workpiece to be machined which are sequentially arranged in the direction of a laser emergent light path. Wherein a laser beam sequentially passes through the system and the element to act on a workpiece to be machined; the light beam dip angle adjusting system and the focus position adjusting system are controlled by the rotating device, the dip angle and parallel displacement of the laser beam relative to the laser optical axis are changed, and drilling machining of different diameters and dip angles is achieved. The focus height adjusting system is controlled by the vibration device, changes the divergence angle of the laser beam and achieves control over the focus height of the laser beam. The light beam inclination angle adjusting system expands the laser beam and optimizes the light spot quality after the laser beam is focused. The device module is simple in structure, can be integrated with conventional laser processing, is easy in light path adjustment, and can realize higher-precision drilling processing.

Description

Technical Field

[0001] The invention relates to the technical field of laser processing devices, and in particular to a high-precision five-axis laser drilling device and method. Background Art

[0002] The basic principle of laser processing is to focus the laser beam on the surface of the material, form a positive cone laser drilling hole on the material through the interaction between the laser beam and the material, and realize various taper structure processing by tilting and moving the sample or laser beam. Since it is difficult to control the tilted sample and the precision is low during the processing, the method of tilting the laser beam is currently mainly used. There are two existing methods to achieve the tilt of the laser beam: rotating or tilting the prism and vibrating the scanning galvanometer. The processing technologies based on these two principles have developed mature optical modules and products.

[0003] The five-axis laser processing equipment based on scanning galvanometer generally includes laser, light guide path, galvanometer scanning laser processing head and machine tool. Its basic principle is: the laser beam output from the laser passes through the light guide path to complete beam expansion and collimation, enters the galvanometer scanning laser processing head, and changes the displacement and inclination of the laser beam by coordinating the vibration angles of multiple galvanometers in the laser processing head. Then, it enters the telecentric lens (F-theta objective lens) for focusing and output to act on the processing object on the machine tool. Among them, the inclination angle of the laser beam is determined by the parallel displacement of the laser beam from the central axis before entering the telecentric lens, and the parallel displacement is limited by the vibration angle of the scanning galvanometer.

[0004] In the current galvanometer scanning five-axis laser processing equipment, the structure of the galvanometer scanning laser processing head is relatively simple and it is difficult to meet the needs of higher precision drilling. Summary of the invention

[0005] The purpose of the present invention is to provide a high-precision five-axis laser drilling device to meet the needs of higher-precision drilling processing in the current laser processing field.

[0006] In order to achieve the above object, the technical solution proposed by the present invention is: A high-precision five-axis laser drilling device, characterized in that the device comprises: a beam tilt adjustment system, a focus height adjustment system, a focus position adjustment system and a focusing optical element arranged in sequence along the laser emission optical path; wherein the laser beam acts on a workpiece to be processed through the beam tilt adjustment system, the focus height adjustment system, the focus position adjustment system and the focusing optical element in sequence; the beam tilt adjustment system and the focus position adjustment system are controlled by a rotating device to change the parallel displacement and tilt of the laser beam relative to the laser optical axis to achieve drilling processing with different tilt angles and diameters; and the beam tilt adjustment system expands the laser beam to reduce the spot diameter after the laser beam is focused; the focus height adjustment system is controlled by a vibration device to change the laser beam divergence angle to achieve laser beam focus height control; The beam tilt adjustment system is composed of four cylindrical reflectors connected to a rotating device; The focus height adjustment system is a concave lens with a vibration device connected to one side; The focal position adjustment system is composed of two plane reflectors connected to a rotating device; The focusing optical element is a telecentric lens.

[0007] Furthermore, the rotating device is a servo motor; and the vibrating device is a voice coil motor.

[0008] A method for achieving high-precision drilling based on the above device comprises the following steps: The first step is to fix and install the beam inclination adjustment system, the focus height adjustment system, the focus position adjustment system and the focusing optical element in sequence according to the laser irradiation line, and place the workpiece to be processed on the machine table; In the second step, the workpiece to be processed is placed under the focusing optical element and the processing part is placed under the laser beam; The third step is to turn on the rotating device and the vibrating device: the four cylindrical reflectors rotate at high speed along axes perpendicular to each other, and the first and second cylindrical reflectors vibrate cooperatively along axes parallel to each other, and the third and fourth cylindrical reflectors rotate cooperatively along axes parallel to each other, respectively controlling the inclination angles of the laser beam in the x and y directions; the concave lens of the focus height adjustment system vibrates back and forth along the optical path of the laser beam to change the divergence angle of the laser beam and control the focus height on the z axis after the laser beam is focused; then the first and second plane reflectors of the focus position adjustment system rotate at high speed along axes perpendicular to each other to respectively control the displacement of the laser beam in the x and y directions until the processing is completed.

[0009] Compared with the prior art, the present invention solves the shortcomings of the existing laser processing device, which is specifically embodied in: Since this device sets the galvanometer in the beam position adjustment system as a cylindrical reflector, the outgoing laser beam can be expanded through the coordinated control of the front and rear cylindrical reflectors. If the diameter of the laser beam is too small, it may cause uneven light intensity distribution in the focal area. After beam expansion, the diameter of the laser beam can be increased, so that the laser beam can achieve an ideal spot shape and uniformity when focusing, thereby making the focal spot of the laser beam better in quality and higher in precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the first embodiment of the present invention; Figure 2 This is a schematic diagram of the principle of using a cylindrical reflector to achieve beam expansion in the present invention. DETAILED DESCRIPTION

[0011] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0012] See also Figure 1-Figure 2 The invention discloses a high-precision five-axis laser drilling device, which receives a laser beam emitted from a laser emitting device. The device comprises: a beam tilt adjustment system 1, a focus height adjustment system 2, a focus position adjustment system 3, a focusing optical element 4 and a workpiece to be processed 5, which are arranged in sequence along the direction of the laser emission optical path; wherein the laser beam acts on the workpiece to be processed 5 through the beam tilt adjustment system 1, the focus height adjustment system 2, the focus position adjustment system 3 and the focusing optical element 4 in sequence.

[0013] See also Figure 1 , Figure 1This is a structural schematic diagram of the first embodiment of the present invention. As can be seen from the figure, the high-precision five-axis laser drilling device receives a laser beam emitted from a laser emitting device. The device includes: a beam tilt adjustment system 1 arranged in sequence along the laser emission light path direction. The beam tilt adjustment system 1 includes four cylindrical reflectors 11, 12, 13 and 14, one side of the cylindrical reflector is connected to a rotating device 15, 16, 17 and 18 respectively through a connecting piece, and the rotating device is a servo motor, which drives the cylindrical reflector to rotate at high speed around a fixed axis; the rotation angles of the four cylindrical reflectors are coordinated in pairs, and the laser beam is reflected at different angles, so as to change the parallel displacement of the laser beam relative to the laser optical axis and realize drilling processing with different tilt angles; and the cylindrical reflectors 11 and 12 expand the laser beam in the x direction, and the cylindrical reflectors 13 and 14 expand the laser beam in the y direction. At the same time, a focus height adjustment system 2 is provided behind the beam inclination adjustment system 1, which includes a concave lens 21, one side of which is connected to a vibration device 22, and the vibration device is a voice coil motor, which drives the concave lens 21 to vibrate back and forth at high speed along the direction of the laser beam optical path, changes the laser beam divergence angle, and realizes the focus height control of the laser beam. At the same time, the focus position adjustment system 3 includes two plane reflectors 31 and 32, one side of which is connected to the rotating device 33 and 34 through a connecting piece, respectively, to reflect the laser beam at different angles, change the inclination of the laser beam relative to the laser optical axis, and thus dynamically change the focus position of the laser beam.

[0014] The focusing optical element 4 is a telecentric lens (also called F-theta objective lens), which can focus the parallel off-axis laser beam to the center point.

[0015] See also Figure 2 , which is a schematic diagram of the principle of using cylindrical reflectors to achieve beam expansion. As can be seen from the figure, the laser beam is first reflected on the convex surface of the cylindrical reflector 11 to obtain a beam divergence angle, so that the diameter of the laser beam is expanded in one direction; then it is reflected by the concave surface of the cylindrical reflector 12, and the divergence angle becomes zero, and the laser beam is expanded laterally and collimated. Similarly, another group of cylindrical reflectors placed perpendicular to the above group of cylindrical reflectors can expand the laser beam in the longitudinal direction, and these two groups of cylindrical reflectors can achieve the overall expansion effect of the laser beam.

[0016] A processing method using a high-precision five-axis laser drilling device includes the following steps: The first step is to fix and install the beam inclination adjustment system 1, the focus height adjustment system 2, the focus position adjustment system 3, and the focusing optical element 4 in sequence according to the laser irradiation line, and place the workpiece 5 to be processed on the machine table; The second step is to place the workpiece 5 to be processed under the focusing optical element 4 and place the processing part under the laser beam; The third step is to turn on the rotating device and the vibrating device: the four cylindrical mirrors vibrate at high speed along mutually perpendicular axes, and the inclination angle of the laser beam in the x direction is controlled by the coordinated vibration of the cylindrical mirrors 11 and 12, and the inclination angle of the laser beam in the y direction is controlled by the coordinated vibration of the cylindrical mirrors 13 and 14, and the laser beam is expanded at the same time; the concave lens 21 vibrates at high speed along the optical axis of the laser beam to change the divergence angle of the laser beam and control the focal height of the laser beam on the z axis after focusing; the displacement of the laser beam in the x and y directions is controlled respectively by the vibration of the plane mirrors 31 and 32.

[0017] The above method can be used to meet the requirement of controlling the taper, and realize drilling of different shapes with higher precision and controllable taper.

Claims

1. A high-precision five-axis laser drilling device, characterized in that: The device comprises: a beam inclination adjustment system, a focus height adjustment system, a focus position adjustment system and a focusing optical element which are arranged in sequence along the direction of the laser emission optical path; wherein the laser beam acts on the workpiece to be processed through the beam inclination adjustment system, the focus height adjustment system, the focus position adjustment system and the focusing optical element in sequence; the beam inclination adjustment system and the focus position adjustment system are controlled by a rotating device to change the parallel displacement and inclination of the laser beam relative to the laser optical axis to achieve drilling processing with different inclination angles and diameters; and the beam inclination adjustment system expands the laser beam to reduce the spot diameter after the laser beam is focused; the focus height adjustment system is controlled by a vibration device to change the divergence angle of the laser beam to achieve focus height control of the laser beam; The beam tilt adjustment system is composed of four cylindrical reflectors connected to a rotating device; The focus height adjustment system is a concave lens with a vibration device connected to one side; The focal position adjustment system is composed of two plane reflectors connected to a rotating device; The focusing optical element is a telecentric lens.

2. The five-axis laser processing device according to claim 1, characterized in that: The rotating device is a servo motor; the vibrating device is a voice coil motor.

3. A method for achieving high-precision drilling based on the device of claim 1, characterized in that: The steps include: The first step is to fix and install the beam inclination adjustment system, the focus height adjustment system, the focus position adjustment system and the focusing optical element in sequence according to the laser irradiation line, and place the workpiece to be processed on the machine table; In the second step, the workpiece to be processed is placed under the focusing optical element and the processing part is placed under the laser beam; The third step is to turn on the rotating device and the vibrating device: the four cylindrical reflectors rotate at high speed along axes perpendicular to each other, and the first and second cylindrical reflectors vibrate cooperatively along axes parallel to each other, and the third and fourth cylindrical reflectors rotate cooperatively along axes parallel to each other, respectively controlling the inclination angles of the laser beam in the x and y directions; the concave lens of the focus height adjustment system vibrates back and forth along the optical path of the laser beam to change the divergence angle of the laser beam and control the focus height on the z axis after the laser beam is focused; then the first and second plane reflectors of the focus position adjustment system rotate at high speed along axes perpendicular to each other to respectively control the displacement of the laser beam in the x and y directions until the processing is completed.

Images