CN114535624B - Method for reducing influence of servo vibration on ultra-precision machining of micro lens array - Google Patents

Abstract

The invention discloses a method for reducing the influence of servo vibration on an ultra-precise machining micro lens array, which comprises the steps of firstly taking the vertex of a cutting edge as a reference point, taking a plane with a certain height from a workpiece as a reference plane, machining the workpiece, extracting the surface data of the machined workpiece by using a white light interferometer, comparing the surface data with the surface data of a theoretical micro lens, obtaining the magnitude of offset error, namely the required advance, and adding the advance when a machining path is adjusted to obtain a new machining path, and obtaining the micro lens with good surface quality by machining by using the machining path. This reduces the influence of the servo vibration on the work surface. Compared with the prior art, the invention has the following advantages: firstly, the method is simple and effective; secondly, the invention can effectively reduce the influence of servo vibration on the micro lens array, and well improves the surface quality of the micro lens.

Description

A Method for Reducing the Influence of Servo Vibration on Ultra-precision Machining Microlens Array

technical field

The invention relates to the technical field of microlens array ultra-precision turning processing, in particular to a method for reducing the influence of servo vibration on ultra-precision machining microlens arrays.

Background technique

The processing size of ultra-precision processing technology can reach sub-micron level, and the processing surface shape accuracy and surface quality are high. Disadvantages subject to wear and unsuitable for harsh environments. Therefore, ultra-precision machining technology is a feasible research direction for the preparation of microlens arrays. However, many factors will affect the surface generation of ultra-precision machining, including the machining environment, the nature of the machined material, and the relative error motion during machining, including the relative error motion between the workpiece and the tool, spindle vibration, tool tip vibration, and servo vibration. Among these many factors, the servo vibration will directly react on the surface of the workpiece through the tool holder, which is one of the key factors affecting the processing quality. The shape of the microlens array is relatively complex, and the reciprocating motion in the Z feed direction of the machine tool is inevitable. When the motion acceleration in this direction is large, it will cause servo vibration phenomenon, which will reduce the processing quality, change the shape of the workpiece, and even cause the machine tool to malfunction. In the original method of ultra-precision machining microlenses, the generated servo vibration has a great influence on the surface quality of microlenses.

Disadvantages of the prior art: the shape of the microlens array is relatively complex, and the reciprocating movement in the Z feed direction of the machine tool is inevitable. When the motion acceleration in this direction is large, it will cause servo vibration phenomenon, which will reduce the processing quality, change the shape of the workpiece, and even cause the machine tool to malfunction. In the traditional method of ultra-precision machining microlenses, the servo vibration generated has a great influence on the surface quality of the microlenses, and the surface quality of the obtained microlenses is relatively poor, which restricts the further development of optics and other fields.

Contents of the invention

In order to solve the problems existing in the prior art, the present invention aims to disclose a method for reducing the influence of servo vibration on microlens arrays in ultra-precision machining, mainly to reduce the impact of servo vibration on microlenses in the process of ultra-precision machining microlens arrays. The influence of the surface improves the surface quality of the microlens.

For reaching this purpose, the present invention adopts following technical scheme:

A method for reducing the influence of servo vibration on an ultra-precision machining microlens array, comprising the following steps:

S1: First, clamp the workpiece on the spindle of the ultra-precision machine tool with a suction cup, select the reference point of the cutting edge, select the reference plane, take this plane as the imaginary plane for machining, extend the microlens to this plane and plan the machining path so that X Axis and C-axis are fed at a constant speed, and machining is realized by changing the cutting depth of the Z-axis;

S2: Then, remove the processed workpiece, extract the surface data of the workpiece (microlens) through the equipment, and match the processed microlens data with the theoretical microlens data according to the resolution of the equipment. Two cross-sectional surface data curves can be obtained along the X direction, and the surface data curves of the two cross-sections are compared. On this basis, N cross-sections are taken along the Y direction to obtain N sets of error data between the theoretical cross-section and the actual cross-section, and then Calculate the average value to get the size of the offset error, that is, the size of the advance amount;

S3: Adjust the processing path according to the calculated advance, and then use this processing path to process the workpiece, and then the optimized microlens array can be obtained;

Further, the suction cup in the step S1 is a vacuum suction cup.

Further, the reference point of the cutting edge in the step S1 is a tool nose point.

Further, the reference plane in the step S1 is a plane at a height h above the workpiece from the machining plane.

Further, the device in step S2 is a white light interferometer.

Further, the two section surface data curves are the surface data curve of the theoretical microlens section and the surface data curve of the processed microlens section.

The beneficial effects of the present invention are:

The invention discloses a method for reducing the influence of servo vibration on ultra-precision machining microlens arrays. Firstly, the cutting edge apex is used as a reference point, and a plane at a certain height from the workpiece is used as a reference plane to process the workpiece, and then a white light interferometer is used to process the microlens array. The processed workpiece surface data is extracted, and then compared with the theoretical microlens surface data, the size of the offset error can be obtained, which is the required advance amount, and then the advance amount is added when the processing path is adjusted to obtain a new The processing path, the microlens with good surface quality can be obtained by processing with this processing path. This reduces the effect of servo vibration on the machined surface. Compared with the traditional technology, the present invention has the following advantages: firstly, the proposed method is simple and effective; secondly, the white light interferometer used in the method has a particularly high precision, and can obtain the surface quality data of the microlens well, which is used for calculating the offset error Good support is provided; the most important thing is that the present invention can effectively reduce the influence of servo vibration on the microlens array, and improve the surface quality of the microlens well.

Description of drawings

Figure 1 is a schematic diagram of an extended surface schematic;

Fig. 2 is the surface data comparison chart of the theoretical microlens cross-section taken along the X direction and the surface data of the microlens cross-section obtained by processing;

Fig. 3 is the schematic diagram of the microlens surface topography that traditional method processing obtains;

Fig. 4 is the schematic diagram of the microlens surface error that traditional method processing obtains;

Fig. 5 is the schematic diagram of the microlens surface topography that processes with the inventive method;

Fig. 6 is a schematic diagram of the surface error of the microlens processed by the method of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the examples and accompanying drawings. As a limitation of the present invention.

Please refer to Figures 1-6, the present invention discloses a method for reducing the influence of servo vibration on ultra-precision machining microlens arrays, including the following steps: S1: First, clamp the workpiece on the spindle of an ultra-precision machine tool with a suction cup, select the cutting As the reference point of the blade, select the datum plane, and take this plane as the imaginary plane for processing, as shown in Figure 1, because there is a certain distance from the workpiece, so the influence of servo vibration will not appear on the processing plane, and then the microlens Extend to this plane and plan the machining path so that the X-axis and C-axis feed at a constant speed, and the machining is realized by changing the cutting depth of the Z-axis;

S2: Then, remove the processed workpiece, extract the surface data of the workpiece (microlens) through the equipment, and match the processed microlens data with the theoretical microlens data according to the resolution of the equipment. Two cross-sectional surface data curves can be obtained along the X direction, and the surface data curves of the two cross-sections are compared, as shown in Figure 2. On this basis, N cross-sections are taken along the Y direction to obtain N groups of theoretical cross-sections and actual The error data of the cross-section, and then calculate the average value, to get the offset error size, that is, the size of the advance amount;

S3: Adjust the processing path according to the calculated advance, and then use this processing path to process the workpiece, and then the optimized microlens array can be obtained;

Further, the suction cup in step S1 is a vacuum suction cup, and the vacuum suction cup is made of nitrile rubber and has a relatively large adsorption force.

Further, the reference point of the cutting edge in step S1 is the tool nose point, which is more direct and reliable.

Further, the reference plane in step S1 is a plane that is above the workpiece at a height h from the machining plane.

Further, the device in step S2 is a white light interferometer, which has a particularly high precision and can obtain good data on the surface quality of the microlens, providing a good support for calculating the offset error.

Further, the two section surface data curves are the surface data curve of the theoretical microlens section and the surface data curve of the processed microlens section.

S1-S3 are the complete process of the present invention.

The surface of the microlens is processed by the above method: firstly, the proposed method is simple and effective; secondly, the white light interferometer used in this method has a particularly high precision, which can obtain the surface quality data of the microlens very well, providing a basis for calculating the offset error The most important thing is that the invention can effectively reduce the influence of the servo vibration on the microlens array and improve the surface quality of the microlens.

Example 1:

This embodiment provides a method for reducing the impact of ultra-precision machining servo vibration on the microlens array. Taking a five-axis ultra-precision machining machine tool as an example, when the machining environment, tool, and spindle speed are consistent, the method of the present invention can be used The workpiece is processed and inspected, and the surface topography of the microlens and the error diagram after removing the microlens structure are shown in Figure 3, Figure 4, Figure 5, and Figure 6. It can be clearly seen from the comparison between several pictures that The surface of the microlens processed by the traditional method has obvious servo vibration phenomenon. There is obvious jitter at the cut-in and cut-out parts, and even the microlens is severely deformed. However, in the microlens surface processed by the method of the present invention, it can be clearly seen from the microlens surface error figure that the jitter caused by the servo vibration has been significantly reduced, and since the tool directly leaves the workpiece surface when cutting out, it will not affect the plane. The quality of the microlens is affected, the offset error when cutting in or cutting out is relatively reduced, and the overall surface processing quality of the microlens is obviously improved. This shows that the inventive method has great practicability.

The above is the embodiment of the present invention. The specific parameters in the above-mentioned embodiments and the embodiments are only for clearly expressing the invention verification process, and are not used to limit the scope of patent protection of the present invention. The scope of patent protection of the present invention is still subject to its claims. Equivalent structural changes made in the description and accompanying drawings should all be included in the protection scope of the present invention.

Claims (5)

1. A method of reducing the effect of servo vibration on ultra-precisely machined microlens arrays, comprising: the method comprises the following steps:

s1: firstly, clamping a workpiece on a main shaft of an ultra-precise machine tool by using a sucker, selecting a cutting edge reference point, selecting a reference plane, taking the reference plane as a processed virtual plane, extending a micro lens to the plane, planning a processing path, enabling an X axis and a C axis to feed at a constant speed, and realizing processing by changing the cutting depth of a Z axis;

s2: then, taking down the processed workpiece, extracting the surface data of the workpiece micro-lens through equipment, matching the processed micro-lens data with the theoretical micro-lens data according to the resolution of the equipment, acquiring two section surface data curves along the X direction, comparing the two section surface data curves, taking N sections along the y direction on the basis, acquiring error data of N groups of theoretical sections and actual sections, and averaging to acquire the offset error, namely the advance;

s3: according to the calculated advance, adjusting a processing path, and then processing a workpiece by using the processing path, so that an optimized microlens array can be obtained;

the reference plane in the step S1 is a plane that is a height from the machining plane h on the workpiece.

2. A method of reducing the effect of servo vibration on an ultra-precision machined microlens array as set forth in claim 1 wherein:

the suction disc in the step S1 is a vacuum suction disc.

3. A method of reducing the effect of servo vibration on an ultra-precision machined microlens array as set forth in claim 1 wherein:

the reference point of the cutting edge in the step S1 is a cutter point.

4. A method of reducing the effect of servo vibration on an ultra-precision machined microlens array as set forth in claim 1 wherein:

the device in the step S2 is a white light interferometer.

5. A method of reducing the effect of servo vibration on an ultra-precision machined microlens array as set forth in claim 1 wherein:

the two section surface data curves are a surface data curve of a theoretical microlens section and a surface data curve of a processed microlens section.