Automatic trimming machining method for composite material structural part

Abstract

The invention discloses an automatic trimming machining method for a composite material structural part. The boundary of the composite material structural part is a straight edge, and direct edge cutting machining is conducted through a saw cutter; and when the boundary of the composite material structural member is a curved edge, a vertical milling cutter is switched for layer milling. The problems that traditional milling machining steps are tedious, the quality is uncontrollable, the safety index is low, the machining cost is high, and the production efficiency is low are solved.

Description

Technical Field

[0001] The invention relates to the technical field of cutting numerical control machining of composite material structural parts, and in particular to an automatic edge trimming machining method for composite material structural parts. Background Art

[0002] The trimming process of composite structural parts (radome) is generally for composite parts or carbon fiber honeycomb sandwich parts. After molding, the size is large and needs to be processed by machine tools to the required boundary size. Affected by the conditions of conventional machine tools, the steps of ordinary milling are very cumbersome, many types of cutting tools are used, and there are major quality risks. After discussion, it was decided to switch to CNC milling machine sawing.

[0003] The existing technical solution is to use special auxiliary material processing tools for processing, using the layer cutting method. Because the auxiliary material workpiece is made of a variety of composite materials. Conventional milling can only use layer cutting. It is impossible to use a tool to cut in one go. Layer cutting has many tool paths, a large program volume, and a long program processing time. Summary of the invention

[0004] The purpose of the present invention is to provide an automatic trimming method for composite material structural parts. The present invention solves the problems of complicated steps, uncontrollable quality, low safety index, high processing cost and low production efficiency in traditional milling.

[0005] Technical solution: An automatic trimming method for composite structural parts, where the boundary of the composite structural part is a straight edge, a sawing tool is used for direct trimming; where the boundary of the composite structural part is a curved edge, an end milling tool is switched for layer milling.

[0006] In the aforementioned automatic trimming method for composite structural parts, when programming the machining route of the sawing knife trimming machining, the bottom surface of the digital model of the composite structural part to be trimmed is used as the reference plane, and the reference plane is offset upward as the plane where the sawing knife center is located; the offset distance L is calculated according to the following formula:

[0007] L=X / 2-Y

[0008] Where X is the saw blade diameter, and Y is the boundary thickness of the composite structural component to be trimmed.

[0009] In the aforementioned automatic trimming processing method for composite structural parts, when programming the processing route of the saw cutting knife trimming processing, if it is a clean edge processing, the boundaries around the digital model of the composite structural part are not processed; if a margin is required, the boundaries around the digital model of the composite structural part are thickened or the surface is offset.

[0010] In the aforementioned automatic trimming method for composite structural parts, when programming the machining route of the sawing knife trimming machining, a plane perpendicular to the reference plane is created as a surface segmentation boundary at the intersection of the straight edge and the curved edge of the composite structural part digital model.

[0011] In the aforementioned automatic trimming method for composite material structural parts, when performing automatic trimming, firstly, an end mill is used to mill and cut the curved edge, and then a saw is used to perform direct trimming.

[0012] In the aforementioned automatic trimming processing method for composite structural parts, the processing route for straight edge cutting by a saw cutter and the processing route for curved edge cutting by an end mill are both compiled in UG modeling software.

[0013] In the aforementioned automatic trimming method for composite material structural parts, the method for compiling the processing route is as follows:

[0014] S1. Open the digital model in UG and perform digital model processing in the "modeling" mode;

[0015] S2. If it is a clean edge machining, the workpiece borders do not need to be processed. If a margin is required, the workpiece borders need to be thickened or offset;

[0016] S3. Create a plane where the saw blade center is located;

[0017] S4. Create a surface segmentation boundary of the straight edge and the curved edge of the composite material structure boundary;

[0018] S5. Enter the programming interface in UG;

[0019] S6. Set "mill_multi-axis multi-axis machining function" and "variable contour milling" in the "Create process" window of the programming interface;

[0020] S7. Select the composite material structural part to be trimmed in the "Part Geometry" window;

[0021] S8. Select the edge to be processed in the "Cutting Area" window;

[0022] S9. Select the "surface / point" processing method in the "driving method"; select the boundary curve of the plane obtained by offsetting the reference plane upward as the driving line;

[0023] S10. In the "Tool" window, enter tool parameters to create a tool;

[0024] S11. In the "Non-cutting move" window, select "Arc - parallel to tool axis" for "Feed and retract".

[0025] In the aforementioned automatic trimming method for composite material structural parts, the sawing tool radius is 55MM.

[0026] Beneficial effects: The present invention is based on the collaborative processing of sawing and milling. The straight edge part is processed by a one-knife cutting method. There are fewer program tool trajectories, shorter program time, higher processing efficiency, and it avoids the quality risks of edge delamination, cracking, burning, etc. in milling processing, effectively improving production efficiency.

[0027] The processing method of the present invention can perform one-knife cutting on composite material structural parts that require edge trimming, such as radar covers and antenna covers, and the operation time is reduced from the traditional 10 hours to 2 hours, thereby improving product processing efficiency and shortening production and processing operation time, saving a total of 8 hours, saving about 8,000 hours for 1,000 pieces, and saving about 640,000 yuan in costs.

[0028] The present invention has been applied to the processing of a certain type of antenna cover, and has been implemented and applied on the production site to process more than 200 products. The use of this sawing processing method reduces the quality problems caused by long-term production of ordinary milling, reduces the labor intensity of operators, reduces labor costs, improves product production efficiency, reduces the machine occupancy time of five-axis equipment, and saves about 5 five-axis equipment resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of step S1 of the processing route of the saw blade edge cutting processing based on the UG software;

[0030] Figure 2 It is a schematic diagram of step S2 of the processing route of the saw blade trimming process based on the UG software;

[0031] Figure 3 It is a schematic diagram of step S3 of the processing route of the saw blade trimming process based on the UG software;

[0032] Figure 4 It is a schematic diagram of step S4 of the processing route of the saw blade trimming process based on the UG software;

[0033] Figure 5 It is a schematic diagram of step S5 of the processing route of the saw blade trimming process based on the UG software;

[0034] Figure 6 It is a schematic diagram of step S6 of the processing route of the saw blade trimming process based on the UG software;

[0035] Figure 7 It is a schematic diagram of step S7 of the processing route of the saw blade trimming process based on the UG software;

[0036] Figure 8 It is a schematic diagram of step S8 of the processing route of the saw blade trimming process based on the UG software;

[0037] Fig. 9It is a schematic diagram of step S9 of the processing route of the saw blade trimming process based on the UG software;

[0038] Fig.10 It is a schematic diagram of step S10 of the processing route of the saw blade trimming processing based on the UG software;

[0039] Fig.11 It is a schematic diagram of step S11 of the processing route of the saw blade trimming processing based on the UG software;

[0040] Fig.12 It is a schematic diagram of step S12 of the processing route of the saw blade trimming processing based on the UG software;

[0041] Fig.13 It is a schematic diagram of step S13 of the processing route of the saw blade trimming processing based on the UG software;

[0042] Fig.14 It is a schematic diagram of step S14 of the processing route of the saw blade trimming processing based on the UG software;

[0043] Fig.15 It is a schematic diagram of step S15 of the processing route of the saw blade trimming processing based on the UG software. DETAILED DESCRIPTION

[0044] Example 1. A composite material structural part automatic trimming method, see Figure 1-Figure 15 When the boundary of the composite material structure is a straight edge, the saw cutter is used for direct edge trimming; when the boundary of the composite material structure is a curved edge, the end milling tool is switched for layer milling. The processing route of the saw cutter edge trimming is compiled based on UG software, and the specific steps are as follows:

[0045] S1 opens the digital model and performs digital model processing in the "modeling" mode: Figure 1 .

[0046] If S2 is a clean edge machining, the workpiece borders do not need to be processed. If a margin is required, the workpiece borders need to be thickened or offset. Figure 2 .

[0047] S3 uses a sawing tool for boundary cutting, but the outer edge of the sawing tool needs to cut the workpiece during sawing, so the center of the machining tool path needs to be eccentrically programmed. The workpiece needs to be cut, so the bottom surface of the workpiece is used as the reference surface for offset. The offset distance formula is {L=X / 2-Y}, where X is the sawing tool diameter and Y is the product boundary thickness. Figure 3 .

[0048] S4 uses a saw cutter to cut at the R angle, which may cause interference between the workpiece and the blank or the workpiece to resist the cutter during the cutting process. Therefore, the workpiece digital model needs to be processed at the R angle. Cut the digital model at the R angle and make two reference planes at the place to be cut, such as Figure 4 . Use the reference plane as the face splitting boundary. Figure 5

[0049] S5 Click Start → Processing button to enter the program editing interface. Figure 6 .

[0050] S6 creates a process - select mill_multi-axis multi-axis machining function, such as Figure 7 . - Variable contour milling, such as Figure 8 .

[0051] The S7 component geometry is selected based on the workpiece being machined. Fig. 9 .

[0052] S8 Cutting area selects the edge to be processed. Fig.10 .

[0053] S9 selects the surface / point processing method in the drive method, such as Fig.11 -Select the offset sheet boundary curve as the driving line. Fig.12 .

[0054] S10 Tool - Create a new tool, enter the corresponding tool data according to the tool parameters. Fig.13 .

[0055] In S11 non-cutting movement, the tool advances and retreats in a circular arc parallel to the tool axis. Fig.14 S12: At this time, the eccentric sawing program is completed. Fig.15 .

Claims

1. A method for automatic trimming of composite material structural parts, characterized in that: When the boundary of the composite structural part is a straight edge, a saw cutter is used for direct edge trimming; when the boundary of the composite structural part is a curved edge, an end milling tool is switched for layer milling.

2. The automatic trimming method for composite material structural parts according to claim 1, characterized in that: When programming the machining route of the sawing cutter trimming process, the bottom surface of the digital model of the composite material structure to be trimmed is used as the reference plane, and the reference plane is offset upward as the plane where the sawing cutter center is located; the offset distance L is calculated according to the following formula: L=X / 2-Y Where X is the saw blade diameter, and Y is the boundary thickness of the composite structural component to be trimmed.

3. The automatic trimming method for composite material structural parts according to claim 1, characterized in that: When programming the machining route of the saw blade trimming machining, if it is a clean edge machining, the boundaries around the digital model of the composite material structure part will not be processed; if a margin is required, the boundaries around the digital model of the composite material structure part will be thickened or the surface will be offset.

4. The automatic trimming method for composite material structural parts according to claim 2, characterized in that: When programming the machining route of saw blade trimming, a plane perpendicular to the reference plane is created as the surface division boundary at the intersection of the straight edge and the curved edge of the composite structure digital model.

5. The automatic trimming method for composite material structural parts according to claim 1, characterized in that: When performing automatic trimming, first use an end mill to mill the curved edge, and then use a saw to perform direct trimming.

6. The automatic trimming method for composite material structural parts according to claim 1, characterized in that: The processing routes for sawing straight edges and end milling curved edges are both compiled in UG modeling software.

7. The automatic trimming method for composite material structural parts according to claim 1, characterized in that: The processing route is compiled as follows: S1. Open the digital model in UG and perform digital model processing in the "modeling" mode; S2. If it is a clean edge machining, the workpiece borders do not need to be processed. If a margin is required, the workpiece borders need to be thickened or offset; S3. Create a plane where the saw blade center is located; S4. Create a surface segmentation boundary of the straight edge and the curved edge of the composite material structure boundary; S5. Enter the programming interface in UG; S6. Set "mill_multi-axis multi-axis machining function" and "variable contour milling" in the "Create process" window of the programming interface; S7. Select the composite material structure to be trimmed in the "Component Geometry" window; S8. Select the edge to be processed in the "Cutting Area" window; S9. Select "Surface / Point" processing mode in "Drive Method"; select the boundary curve of the plane obtained by upward offset of the reference plane as the drive line; S10. In the "Tool" window, enter tool parameters to create a tool; S11. In the "Non-cutting move" window, select "Arc - parallel to tool axis" for "Feed and retract".

8. The automatic trimming method for composite material structural parts according to claim 1, characterized in that: The sawing tool radius is 55MM.

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