Method for machining curved corner mirrors

Abstract

The application discloses a curved corner mirror machining method, which uses a numerical control machine tool to process a right-angle corner of a workpiece into a mirror curved corner, and the numerical control machine tool is provided with a tool disc driven by three shafts and an angle head, the tool disc is provided with first, second and third cutters in a linear structure, and the angle head is provided with a self-rotating rolling cutter, and the method comprises the following steps: establishing a mathematical model of the workpiece, importing a curvature radius and an arc line of a curved corner to be machined, and marking a part to be cut in the mathematical model; and sequentially calling the first cutter, the second cutter, the third cutter and the rolling cutter in sequence to perform linear cutting on the workpiece, so as to cut off the triangular region protruding the most outwardly, and finally, a milling cutter is used to perform a milling process, so that the curved corner surface can be quickly and effectively formed into a qualified mirror surface effect. It can be seen that the curved corner mirror machining method has good mirror surface effect, high machining precision and high machining efficiency.

Description

Technical Field

[0001] This invention relates to the field of industrial automation, and more particularly to a method for machining right-angle corners of workpieces into a mirror finish using a CNC machine tool. Background Technology

[0002] High-precision metal mirrors are widely used in key technological fields such as deep space exploration and astronomical observation. Currently, they are mainly manufactured using ultra-precision turning methods. Under conditions of using high-precision CNC machine tools and strictly controlling the vibration, temperature, and humidity of the processing environment, it is already possible to obtain metal mirrors with nanoscale surface roughness. The key factor limiting further improvements in the machining accuracy of metal mirrors is the metallographic structure of the material. Specifically, the metal materials used in mirror machining are generally polycrystalline. During the manufacturing process of polycrystalline materials, factors such as solidification rate result in larger metal grain sizes and poor grain orientation consistency. Different grain orientations lead to different mechanical properties between adjacent metal grains, resulting in different elastic recovery values ​​after turning, ultimately leading to a significant increase in the surface roughness of ultra-precision turned metal mirrors. Therefore, due to the influence of the existing metallographic structure of metal materials, the machining accuracy of metal mirrors cannot be further improved.

[0003] Therefore, there is an urgent need to provide a method for processing curved corner mirrors with high precision and high efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a method for processing curved corner mirrors with high precision and high efficiency.

[0005] To achieve the above objectives, this invention provides a method for machining a curved corner into a mirror-like surface. The method uses a CNC machine tool to machine a right-angle corner of a workpiece into a mirror-like curved corner. The CNC machine tool is characterized by having a three-axis driven cutter head and an angle head. The cutter head is equipped with a first, second, and third cutter with linear structures. The angle head is equipped with a rotatable rolling cutter. The rolling cutter is cylindrical and has several protruding blades. The method for machining a curved corner into a mirror-like surface includes:

[0006] Obtain the radius of curvature and arc length of the curve corner;

[0007] Obtain the geometric parameters of the workpiece and establish the corresponding mathematical model;

[0008] The right-angle corners that need to be processed are identified in the mathematical model.

[0009] The radius of curvature and arc length are imported into the mathematical model, and the portion that needs to be removed is marked.

[0010] From the marked portion that needs to be removed, find the edge points A and B on both sides and the right-angle corner point C;

[0011] A first cutting scheme is generated using the midline of line segment AC and line segment BC to control the feed path of the first tool. After cutting, the first cutting scheme forms endpoint D on line segment AC and endpoint E on line segment BC.

[0012] A second cutting scheme is generated using the midline of line segment AD and line segment ED to control the feed path of the second tool. After cutting, the second cutting scheme forms endpoint F on line segment AD and endpoint G on line segment ED.

[0013] A third cutting scheme is generated by connecting the midpoint and endpoint G of line segment BE to control the feed path of the second tool. After cutting, the third cutting scheme forms endpoint H on line segment BE. The feed path direction of the second cutting scheme is from endpoint F to endpoint G, and the feed path direction of the third cutting scheme is from endpoint G to endpoint H. The second tool deflects at a certain angle at endpoint G to execute the third cutting scheme in the direction from endpoint G to endpoint H.

[0014] A fourth cutting scheme is generated using the midline of line segment FG and line segment GH to control the feed path of the third tool. After cutting, the fourth cutting scheme forms endpoint I on line segment FG and endpoint J on line segment GH.

[0015] The remaining arc AB and the broken line segment A-F-I-J-H-B constitute the hobbing area, and the hobbing area is used to generate a surface cutting scheme that controls the feed path and offset of the rolling cutter.

[0016] The workpiece is fixed on the platform of the CNC machine tool, and the first cutting scheme, the second cutting scheme, the third cutting scheme, the fourth cutting scheme and the curved surface cutting scheme are imported into the CNC machine tool;

[0017] The CNC machine tool sequentially performs the cutting of the workpiece according to the first cutting scheme, the second cutting scheme, the third cutting scheme, the fourth cutting scheme and the curved surface cutting scheme, forming a curved corner with a semi-mirror effect; the CNC machine tool has a preset value that characterizes the mirror effect of the curved corner, and the preset value is the reflectivity of the curved corner surface to light;

[0018] The semi-mirror effect curved corner surface is milled using a milling cutter instead of the rolling cutter; if the reflectivity of the curved corner surface reaches a preset value, the milling of the curved corner surface is stopped; if the reflectivity of the curved corner surface does not reach the preset value, the milling of the curved corner surface continues until the preset value is reached.

[0019] This invention precisely determines the portion to be removed by importing the data of the curved corner to be machined into a mathematical model based on the workpiece's geometric parameters. Based on the position of this portion within the right-angle corner, the four most protruding triangular areas are sequentially cut away from the outside inwards using a centerline method with straight-line cutting, ultimately forming a closed hobbing area composed of an arc on one side and multiple broken line segments on the other. This hobbing area is then cut away by the rotation and offset of a cylindrical rolling cutter with inserts, creating a semi-mirror-like curved corner. Finally, the semi-mirror-like curved corner surface is milled using a milling cutter instead of the rolling cutter to obtain a standard mirror-like curved corner. This invention sequentially uses a first tool, a second tool, a third tool, a rolling cutter, and a milling cutter to process the workpiece. Specifically, this invention achieves the goal of machining a right-angle corner into a mirror-like curved corner through four consecutive linear cutting, rolling cutting, and milling processes. This decomposes the entire machining process into several tool-specific control programs, effectively breaking down a complex process into several simpler programs, thus improving both machining accuracy and efficiency. Furthermore, the final milling process with the milling cutter quickly and effectively achieves the desired mirror finish on the curved corner surface. Therefore, this invention's curved corner mirror machining method produces a high-quality mirror finish with high precision and high efficiency.

[0020] Preferably, in the method for machining curved corner mirror surfaces of the present invention, the step of obtaining the geometric parameters of the workpiece and establishing a corresponding mathematical model further includes: obtaining the design parameters of the workpiece and the actual parameters of the workpiece produced according to the design parameters; establishing a workpiece model based on the design parameters and the actual parameters; extracting the geometric parameters of the workpiece from the workpiece model; and establishing a corresponding mathematical model using SolidWorks software based on the geometric parameters. The present invention establishes a mathematical model using SolidWorks software based on the design parameters and actual parameters, ensuring the accuracy of the mathematical model by correcting the actual parameters based on the theoretical design parameters. This provides accurate data for the subsequent cutting scheme based on this mathematical model, further improving the machining accuracy and mirror effect of the present invention. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a workpiece according to an embodiment of the present invention.

[0022] Figure 2a In order to be in Figure 1 The state diagram of the first cutting scheme based on the calibration.

[0023] Figure 2b for Figure 2aA schematic diagram of the structure after the first cutting scheme is completed.

[0024] Figure 3a In order to be in Figure 2b The state diagram of the second cutting scheme, which was calibrated based on the above.

[0025] Figure 3b for Figure 3a A schematic diagram of the structure after completing the second cutting scheme.

[0026] Figure 4a In order to be in Figure 3b The state diagram of the third cutting scheme, which was calibrated based on the above.

[0027] Figure 4b for Figure 4a A schematic diagram of the structure after completing the third cutting scheme.

[0028] Figure 5a In order to be in Figure 4b The state diagram of the fourth cutting scheme, which was calibrated based on the above.

[0029] Figure 5b for Figure 5a A schematic diagram of the structure after completing the fourth cutting scheme.

[0030] Figure 6a for Figure 5b Based on this, the state diagram of the hobbing zone is calibrated.

[0031] Figure 6b for Figure 6a A schematic diagram of the structure after the curved surface cutting scheme is completed.

[0032] Figure 7 This is a schematic diagram of the structure of the rolling cutter of the present invention. Detailed Implementation

[0033] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to specific implementation examples and accompanying drawings, and the technical solutions of the present invention will be explained. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. Embodiments of the present invention will now be described with reference to the accompanying drawings, in which similar element reference numerals represent similar elements.

[0034] like Figure 1 - Figure 7 As shown, the method for machining a mirror-finished curved corner of the present invention is used to machine a right-angled corner of a workpiece 100 into a mirror-finished curved corner using a CNC machine tool. The CNC machine tool used in this invention has a three-axis driven cutter head and an angle head. The cutter head is equipped with a first cutter, a second cutter, and a third cutter with linear structures. The angle head is equipped with a rotatable rolling cutter 1, which is cylindrical in shape and has several protruding blades 11. Specifically, the blades are strip-shaped with a triangular pyramidal cross-section. Specifically, the method for machining a mirror-finished curved corner of the present invention includes:

[0035] Step 1: Obtain the radius of curvature and arc length of the curve corner; this can be understood as: the radius of curvature and arc length of the curve corner are... Figure 1 The radius of curvature and arc length of arc AB in the diagram.

[0036] Step 2: Obtain Figure 1 The geometric parameters of the workpiece 100 shown are determined and a corresponding mathematical model is established.

[0037] Step 3: Identify the right-angle corners that need to be processed in the mathematical model.

[0038] Step 4: Import the radius of curvature and arc length into the mathematical model, and mark the portion that needs to be removed; this can be understood as: the portion that needs to be removed is... Figure 1 The shaded area shown in the image.

[0039] Step 5: From the marked area to be removed, find the edge points A and B on both sides, and the right-angle corner point C. See details below. Figure 1 As shown.

[0040] Step 6: Using the midline L1 of line segments AC and BC ( Figure 2a As shown, a first cutting scheme is generated to control the feed path of the first tool. After cutting, the first cutting scheme forms endpoint D on line segment AC and endpoint E on line segment BC. This can be understood as: the first cutting scheme is... Figure 2a Cut along the dotted line L1. Figure 2a The shaded area; cut off Figure 2a The shaded area is obtained Figure 2b The shape shown.

[0041] Step 7: Using the midline L2 of line segments AD and ED ( Figure 3a As shown, a second cutting scheme is generated to control the feed path of the second tool. After cutting, the second cutting scheme forms endpoint F on line segment AD and endpoint G on line segment ED. This can be understood as: the second cutting scheme is...Figure 3a Cut along the dotted line L2. Figure 3a The shaded area; cut off Figure 3a The shaded area is obtained Figure 3b The shape shown.

[0042] Step 8: Connect line L3 (the midpoint of line segment BE and the endpoint G) Figure 4a As shown, a third cutting scheme is generated to control the feed path of the second tool. After cutting, the third cutting scheme forms an endpoint H on the line segment BE. The feed path direction of the second cutting scheme is from endpoint F to endpoint G, and the feed path direction of the third cutting scheme is from endpoint G to endpoint H. The second tool deflects at a certain angle at endpoint G to execute the third cutting scheme in the direction from endpoint G to endpoint H. This can be understood as: the third cutting scheme is... Figure 4a Cut along the dotted line L3 on the basis of Figure 4a The shaded area; cut off Figure 4a The shaded area is obtained Figure 4b The shape shown; the angle at which the second cutter deflects at endpoint G is the angle between the dashed line L3 and the line segment GE.

[0043] Step 9: Using the midline L4 of line segments FG and GH ( Figure 5a As shown, a fourth cutting scheme is generated to control the feed path of the third tool. After cutting, the fourth cutting scheme forms endpoint I on line segment FG and endpoint J on line segment GH. This can be understood as: the third cutting scheme is... Figure 5a Cut along the dotted line L4. Figure 5a The shaded area; cut off Figure 5a The shaded area is obtained Figure 5b The shape shown.

[0044] Step 10: The remaining arc AB and the broken line segment A-F-I-J-H-B constitute the hobbing zone. Figure 6a (As shown in the shaded area), a surface cutting scheme that controls the feed path and offset of the rolling cutter is generated in the rolling cutter area.

[0045] Step 11: Fix the workpiece on the platform of the CNC machine tool, and import the first cutting scheme, the second cutting scheme, the third cutting scheme, the fourth cutting scheme and the curved surface cutting scheme into the CNC machine tool.

[0046] Step 12: The CNC machine tool sequentially executes the cutting of the workpiece according to the first cutting scheme, the second cutting scheme, the third cutting scheme, the fourth cutting scheme, and the curved surface cutting scheme, forming a curved surface corner with a semi-mirror effect; that is, the state of workpiece 100 changes from... Figure 1- Figure 2b - Figure 3b - Figure 4b - Figure 5b - Figure 6b The CNC machine tool of the present invention has a preset value that characterizes the mirror effect of curved corners, wherein the preset value is the reflectivity of the curved corner surface to light;

[0047] Step 13: Replace the rolling cutter with a milling cutter to mill the curved corner surface with a semi-mirror effect, i.e., mill the surface. Figure 6a The curved surface AB (i.e., arc AB) in the indicated state is milled. If the reflectivity of the curved corner surface reaches a preset value, milling of the curved corner surface stops; if the reflectivity of the curved corner surface does not reach the preset value, milling of the curved corner surface continues until the preset value is reached. Specifically, the present invention uses an existing light source generator and light source detector on a CNC machine tool. When milling the curved corner surface, the light source generator continuously emits light of a fixed intensity onto a fixed area of ​​the curved corner surface. The light source detector detects the intensity of the reflected light reflected back from the surface in real time. When the ratio of the intensity of the reflected light to the intensity of the emitted light reaches a preset reflectivity, the light source detector sends a stop milling signal to the control panel of the CNC machine tool. The control panel controls the milling cutter to shut down, thereby completing the curved corner processing to achieve the desired mirror effect.

[0048] like Figure 1 - Figure 7As shown, this invention imports the data of the curved corner to be processed into a mathematical model established based on the workpiece's geometric parameters, thereby accurately determining the portion to be removed. Based on the position of the portion to be removed within the right-angle corner, the four most protruding triangular areas are sequentially cut away from the outside to the inside using a straight-line cutting method via the centerline method, ultimately forming a closed hobbing area composed of an arc on one side and multiple broken line segments on the other. This hobbing area is then cut away by the rotation and offset of a cylindrical rolling cutter with inserts, forming a semi-mirror-like curved corner. Finally, the surface of the semi-mirror-like curved corner is milled using a milling cutter instead of the rolling cutter to obtain a standard mirror-like curved corner. This invention sequentially uses a first tool, a second tool, a third tool, a rolling cutter, and a milling cutter to process the workpiece. Specifically, this invention achieves the goal of machining a right-angle corner into a mirror-like curved corner through four consecutive linear cutting, rolling cutting, and milling processes. This decomposes the entire machining process into several tool-specific control programs, effectively breaking down a complex process into several simpler programs, thus improving both machining accuracy and efficiency. Furthermore, the final milling process with the milling cutter quickly and effectively achieves the desired mirror finish on the curved corner surface. Therefore, this invention's curved corner mirror machining method produces a high-quality mirror finish with high precision and high efficiency.

[0049] More specifically, in the curved corner mirror surface machining method of the present invention, the step of obtaining the geometric parameters of the workpiece and establishing a corresponding mathematical model further includes: obtaining the design parameters of the workpiece and the actual parameters of the workpiece produced according to the design parameters; establishing a workpiece model according to the design parameters and the actual parameters; extracting the geometric parameters of the workpiece from the workpiece model; and establishing a corresponding mathematical model using SolidWorks software based on the geometric parameters. The present invention establishes a mathematical model using SolidWorks software based on the design parameters and actual parameters, ensuring the accuracy of the mathematical model by correcting the actual parameters based on the theoretical design parameters. This provides accurate data for the subsequent cutting scheme based on this mathematical model, further improving the machining accuracy and mirror surface effect of the present invention.

[0050] The basic structure and working principle of the CNC machine tool involved in this invention are well known to those skilled in the art, and will not be described in detail here.

[0051] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims. Furthermore, the embodiments disclosed above are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Therefore, equivalent variations made within the scope of the claims are still within the scope of the present invention.

Claims

1. A method for machining a curved corner into a mirror surface, comprising using a CNC machine tool to machine a right-angle corner of a workpiece into a mirror-like curved corner, characterized in that, The CNC machine tool has a three-axis driven cutter head and an angle head. The cutter head is equipped with a first cutter, a second cutter, and a third cutter with linear structures. The angle head is equipped with a rotatable rolling cutter. The rolling cutter is cylindrical and has several protruding blades. The method for machining curved corner mirror surfaces includes: Obtain the radius of curvature and arc length of the curve corner; Obtain the geometric parameters of the workpiece and establish the corresponding mathematical model; The right-angle corners that need to be processed are identified in the mathematical model. The radius of curvature and arc length are imported into the mathematical model, and the portion that needs to be removed is marked. From the marked portion that needs to be removed, find the edge points A and B on both sides and the right-angle corner point C; A first cutting scheme is generated by connecting the midpoints of line segments AC and BC to control the feed path of the first tool. After cutting, the first cutting scheme forms endpoint D on line segment AC and endpoint E on line segment BC. A second cutting scheme is generated by connecting the midpoints of line segments AD and ED to control the feed path of the second tool. After cutting, the second cutting scheme forms endpoint F on line segment AD and endpoint G on line segment ED. A third cutting scheme is generated by connecting the midpoint and endpoint G of line segment BE to control the feed path of the second tool. After cutting, the third cutting scheme forms endpoint H on line segment BE. The feed path direction of the second cutting scheme is from endpoint F to endpoint G, and the feed path direction of the third cutting scheme is from endpoint G to endpoint H. The second tool deflects at a certain angle at endpoint G to execute the third cutting scheme in the direction from endpoint G to endpoint H. A fourth cutting scheme is generated by connecting the midpoints of line segments FG and GH to control the feed path of the third tool. After cutting, the fourth cutting scheme forms endpoint I on line segment FG and endpoint J on line segment GH. The remaining arc AB and the broken line segment AFIJHB constitute the hobbing area, and the hobbing area is used to generate a surface cutting scheme that controls the feed path and offset of the rolling cutter. The workpiece is fixed on the platform of the CNC machine tool, and the first cutting scheme, the second cutting scheme, the third cutting scheme, the fourth cutting scheme and the curved surface cutting scheme are imported into the CNC machine tool; The CNC machine tool sequentially performs the cutting of the workpiece according to the first cutting scheme, the second cutting scheme, the third cutting scheme, the fourth cutting scheme and the curved surface cutting scheme, forming a curved corner with a semi-mirror effect; the CNC machine tool has a preset value that characterizes the mirror effect of the curved corner, and the preset value is the reflectivity of the curved corner surface to light; The semi-mirror effect curved corner surface is milled using a milling cutter instead of the rolling cutter; if the reflectivity of the curved corner surface reaches a preset value, the milling of the curved corner surface is stopped; if the reflectivity of the curved corner surface does not reach the preset value, the milling of the curved corner surface continues until the preset value is reached.

2. The method for processing curved corner mirrors as described in claim 1, characterized in that, The step of obtaining the geometric parameters of the workpiece and establishing the corresponding mathematical model further includes: Obtain the design parameters of the workpiece and the actual parameters of the workpiece produced based on the design parameters; Based on the design parameters and the actual parameters, a workpiece model is established; Extract the geometric parameters of the workpiece from the workpiece model; Based on the aforementioned geometric parameters, a corresponding mathematical model is established using SolidWorks software.

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