A processing method of a wing assembly support

Abstract

The application relates to a processing method of a missile wing mounting support, which comprises the following steps: drawing a circumferential reference line on the position of a busbar according to the actual position of the missile wing mounting support; clamping a missile shell on an equipment to find a plane; finding the highest point of the busbar in the axial busbar length range after the missile wing is mounted as the radial reference of the missile wing mounting support; and coarsely processing each surface of the missile wing mounting support according to the determined axial (the end surface of the missile shell), radial and circumferential references, and then finely processing and semi-finely processing one side of the missile wing mounting support in the radial direction, and then reversing by 180 DEG to process the other side of the missile wing mounting support. In the application, new processing steps are adopted, the influence of the tremor caused by the weak systematic stiffness of the structural member on the size precision and the influence of the tool setting on the size precision are solved, and the influence of the deformation caused by the cutting force on the size precision is eliminated.

Description

Technical Field

[0001] This invention belongs to the field of precision machining technology for composite structural components, and relates to a machining method for a missile wing assembly bracket. Background Technology

[0002] The missile fins are a crucial component of a missile, primarily responsible for generating lift during flight and stabilizing its attitude. Mounting brackets for these fins are welded at specific intervals to the missile's two sides along its axis. Ensuring dimensional and positional accuracy guarantees the fin assembly precision, ensuring balanced force distribution during flight. The fin mounting brackets are typically 3mm to 4mm thick, with each side's reference surfaces required to be identical, and there are relative positional accuracy requirements for these surfaces. Therefore, the fin mounting brackets are usually constructed by welding a pre-machined blank to the missile casing, followed by overall machining to ensure both positional accuracy within the missile and dimensional accuracy.

[0003] Current technology for missile wing mounting brackets involves vertical milling. However, due to the missile casing's large dimensions (≥Φ400mm), thin walls (1.2mm~2.0mm), poor systemic rigidity, high material hardness (approximately HRC50), and high machining difficulty, its main disadvantages are:

[0004] 1. Poor system rigidity makes it prone to chattering under cutting forces, which affects machining accuracy;

[0005] 2. To reduce the impact of cutting forces on the workpiece, auxiliary tooling is needed to strengthen the rigidity of each wing mounting bracket. However, this also affects the accuracy of the machined parts due to the clamping force of the auxiliary tooling. Furthermore, due to the clamping position of the auxiliary tooling, each wing mounting bracket can only be machined on one surface, requiring multiple tooling changes.

[0006] 3. As the thickness of the missile wing mounting bracket continues to decrease, it is easy to cause tool deflection, resulting in a difference in size between the root and the top. The root size is 0.15mm to 0.2mm larger than the top size. The difference in size between the upper and lower dimensions exceeds the dimensional tolerance required by the design. It requires manual grinding by a fitter, which is labor-intensive for the operator, results in poor product consistency, and has an unsightly surface quality.

[0007] 4. In order to reduce the impact of tool deflection on dimensional accuracy and reduce the amount of grinding by fitters, the depth of cut during the machining process is gradually reduced, resulting in low production efficiency, failure to take full advantage of CNC machining, and certain quality risks.

[0008] In summary, existing processing methods have become a bottleneck technical problem restricting production efficiency. It is necessary to carry out research in this processing field to provide technical reference for the processing of similar structures. Summary of the Invention

[0009] Technical problems to be solved

[0010] To overcome the shortcomings of existing technologies, this invention proposes a processing method for a missile wing assembly bracket, addressing drawbacks such as poor product quality consistency, low production efficiency, and inability to achieve CNC machining. It provides a new process technology that solves practical production bottlenecks, achieving the goal of fully meeting dimensional accuracy requirements through CNC machining.

[0011] The technical problem to be solved by the present invention is to improve the consistency and reliability of product quality, increase production efficiency, and reduce labor costs by adopting new process methods.

[0012] Technical solution

[0013] A method for processing a missile wing assembly bracket, characterized by the following steps:

[0014] On the platform, the center line of the missile casing is aligned by diameter, and machining allowance is left for each wing. Two circumferential reference lines, 0° and 180°, are drawn at the generatrix position.

[0015] The missile casing is horizontally clamped in the CNC milling machine to control the runout of the outer circles at both ends of the missile casing within the design range, and to ensure that the axis of the missile casing is consistent with the rotation axis of the CNC milling machine.

[0016] Within the generatrix length range after the wing is to be installed at 0° and 180°, the highest point of the shell is determined as the radial machining reference for the wing mounting bracket to ensure that there is no interference between the wing and the shell during assembly.

[0017] The end face of the missile casing is used as the axial machining reference.

[0018] The drawn circumferential reference line is used as the circumferential machining reference for CNC milling.

[0019] This provides the axial, radial, and axial machining references for machining the various surfaces of the wing mounting bracket on the missile casing.

[0020] Machine each wing mounting bracket on one side according to the following steps, then rotate 180° to machine each wing mounting bracket on the other side:

[0021] Step 1) Machining the radial height dimension to the finishing height dimension indicated on the drawing;

[0022] Step 2) Perform semi-finishing in the radial direction, then finish machining, so that the upper half of the radial height direction of the missile wing mounting bracket is in place by 1 / 2 to 1 / 3 of the dimension, while retaining the lower half to ensure the rigidity of the machined part and eliminate tool deflection and chatter;

[0023] Step 3) Perform semi-finish machining on the lower half of the missile wing mounting bracket in the radial direction along its height.

[0024] Step 4) Perform radial machining on the lower half of the missile wing mounting bracket to the required dimensions in the height direction;

[0025] Finally, the mounting holes are machined.

[0026] The circumferential baseline must ensure the allowance for each machined surface in the design drawings.

[0027] The circumferential reference line takes into account the margin of multiple wing mounting brackets on both sides, and two circumferential reference lines are drawn at 0° and 180° on the outer circle.

[0028] The runout of the outer circles at both ends is controlled within the design range of 0.1 to 0.2 mm.

[0029] When processing each wing mounting bracket, rough machining, semi-finishing, and finishing are performed at a determined position in the height direction.

[0030] The roughing speed is 2200-2500 r / min, the feed rate is 280-300 mm / min, and the depth of cut is 0.4-0.6 mm.

[0031] The semi-finishing speed is 2800-3000 r / min, the feed rate is 380-400 mm / min, and the depth of cut is 0.2-0.3 mm.

[0032] The finishing speed is 2800-3000 r / min, the feed rate is 380-400 mm / min, and the depth of cut is 0.1-0.15 mm.

[0033] The side edge of the milling cutter of the CNC milling equipment contacts the machining surface.

[0034] The tool path is rectangular.

[0035] Beneficial effects

[0036] This invention proposes a machining method for a missile wing mounting bracket. The method involves drawing a circumferential reference line at the generatrix position, referencing the actual position of the missile wing mounting bracket, to ensure sufficient and uniform machining allowance on each surface. The missile casing is clamped onto a CNC milling machine, and the runout of the outer diameters at both ends is aligned within a certain range. After the missile wing is installed, the highest point of the generatrix within the axial generatrix length range is used as the radial reference for the missile wing mounting bracket, ensuring that the missile wing does not interfere with the casing after assembly. Based on the determined axial (missile casing end face), radial, and circumferential references, each surface of the missile wing mounting bracket is rough-machined to eliminate large allowances and improve production efficiency. One side of the missile wing mounting bracket is then finished and semi-finished radially, and then rotated 180° to machine the other side.

[0037] 1. Reduced machining difficulty: The invention adopts new machining steps, which solves the problem of the impact of vibration caused by the weak system rigidity of structural components on dimensional accuracy and the impact of tool deflection on dimensional accuracy. Overall, it eliminates the impact of deformation caused by cutting force on dimensional accuracy.

[0038] 2. Improved efficiency: CNC milling precisely shapes the parts, eliminating repeated processing and tracking inspection processes, as well as manual work by fitters. This reduces the transfer and inspection time between processes, shortens the processing cycle, and increases production efficiency by 2 times.

[0039] 3. Improve product quality stability and consistency: CNC milling reduces manual work by fitters, improving the stability of product dimensions and the consistency of surface quality.

[0040] 4. Reduced labor intensity: Eliminates the manual filing process for fitters, reducing labor costs and lowering the labor intensity of operators.

[0041] 5. Reduce auxiliary tooling: This solves the problem of using auxiliary tooling to support and enhance the rigidity of the machined parts, reduces the clamping and adjustment time of the tooling, avoids the impact of the clamping force of the auxiliary tooling on the machining accuracy, and avoids the interference of the clamping position of the auxiliary tooling on the machining path.

[0042] 6. Technical refinement and promotion value: By mastering the influence of cutting force generated by the cutting direction on dimensional accuracy during the machining of thin-walled structural parts, the cutting direction has been optimized from the original Y-axis full-side cutting to Z-axis segmented, layered, and trajectory-changing machining. By reducing the contact area between the tool and the machining part, the impact of cutting force on machining accuracy is reduced, and tool deflection is avoided. The technical experience can be refined and promoted for application in the machining of other similar structural parts. Attached Figure Description

[0043] Figure 1 This serves as the machining reference for the missile wing mounting bracket.

[0044] Figure 2 Existing technology processing methods for wing mounting brackets.

[0045] Figure 3 A post-invention processing method for the missile wing mounting bracket was invented.

[0046] Figure 4 The diagram shows the structural dimensions of the missile wing mounting bracket after processing, as shown in the example.

[0047] Figure 5 This is a partial enlarged view of an embodiment.

[0048] Figure 6 This is a drawing of the blank dimensions before welding, as shown in the example.

[0049] Figure 7 This is a dimensional diagram of the processed parts for an example. Detailed Implementation

[0050] The present invention will now be further described in conjunction with the embodiments and accompanying drawings:

[0051] The example of the missile wing mounting bracket will be used for illustration.

[0052] The wing mounting brackets are distributed on both sides of the missile casing, with a total of 8 brackets in two rows. The height difference between the reference plane of the two rows of wing mounting brackets and the center is no more than 0.2mm, in order to ensure the symmetry of the wing after installation and the uniformity of the force during flight.

[0053] The thickness of the wing mounting bracket is 3mm ± 0.1mm, and its height from the missile casing generatrix is ​​[missing information]. Width is The surface has mounting holes for assembling missile wings.

[0054] The missile casing is a cylindrical, thin-walled structure, assembled from a cylindrical body, front connector, and rear connector through welding and heat treatment. It is made of high-strength steel with a hardness of HRC48–52, and its outer diameter is [missing information]. The wall thickness is 1.7mm. The cylinder of the welded missile wing mounting bracket is formed by spinning. After welding and heat treatment, its straightness and roundness are deformed to a certain extent. Therefore, the two generatrices of the welded missile wing mounting bracket will fluctuate.

[0055] The axial length span of the wing mounting bracket after the wing is assembled is 1000mm.

[0056] The structural dimensions of the missile wing mounting bracket after machining are shown in the figure. Figure 4 For enlarged dimensions, see [link / reference]. Figure 5 The dimensions of the blank before welding are shown in the figure. Figure 6 .

[0057] The specific processing steps are as follows:

[0058] 1) After the fitter aligns the missile casing centerline on the platform using the diameter measurement, refer to... Figure 6 The blank has a 3mm margin relative to the reference surface. To accommodate the margin of the eight missile wing mounting brackets on both sides, two circumferential reference lines are drawn at 0° and 180° on the outer circle.

[0059] 2) On a milling machine, ensure the runout of the outer diameter at both ends of the missile casing is within 0.1 mm;

[0060] 3) Find the reference line drawn by the fitter and determine whether 0° and 180° coincide. If they do not coincide, they can be adjusted appropriately to take into account both 0° and 180°, and determine the CNC milling circumferential machining reference.

[0061] 4) Determine the highest point of the shell within a 1000mm generatrix range of the 0° and 180° axial direction of the baseline as the height machining reference for the wing mounting bracket, that is, determine the radial machining reference to ensure that there is no interference between the wing and the shell when assembling the wing.

[0062] 6) Using the radial datum as a reference, rough, semi-finish, and finish machine the height dimensions of the four missile wing mounting brackets at the 0° position one by one. Roughing speed: 2500 r / min, feed rate: 300 mm / min; Semi-finishing and finishing speed: 3000 r / min, feed rate: 400 mm / min. Roughing depth of cut: 0.5 mm; Semi-finishing depth of cut: 0.2 mm; Finishing depth of cut: 0.1 mm.

[0063] 7) Rotate 180° and process the other four on the other side as in step 6);

[0064] 8) Rotate 180° and perform roughing, semi-finishing, and finishing at a height of 12mm. Roughing speed: 2500 rpm, feed rate: 300 mm / min. Semi-finishing and finishing speeds: 3000 rpm, feed rate: 400 mm / min. Roughing depth of cut: 0.5mm; semi-finishing depth of cut: 0.2mm; finishing depth of cut: 0.1mm. See the cutting direction for details. Figure 2 The end mill's side cutting edge has a 12mm length that contacts the machined surface. The tool path is rectangular. The dimensions after machining are shown in the figure. Figure 7 ;

[0065] 9) Rotate 180° and process the other four on the other side as in step 8);

[0066] 10) Rotate 180°, then perform roughing, semi-finishing, and finishing at the remaining height position. Roughing: 2500 rpm, feed rate 300 mm / min; Semi-finishing and finishing: 3000 rpm, feed rate 400 mm / min. Roughing depth of cut: 0.5 mm, leaving a 0.5 mm allowance on each side for semi-finishing; Semi-finishing depth of cut: 0.2 mm, leaving a 0.1 mm allowance on each side for finishing; Finishing depth of cut: 0.1 mm to dimension. See the cutting direction for details. Figure 3 The tool path is rectangular;

[0067] 11) Machining the mounting holes for each missile wing mounting bracket on both sides respectively.

[0068] The missile wing mounting brackets processed according to the above process fully meet the thickness requirement of 3mm±0.1mm. The height difference between the eight brackets and the reference surface can be controlled within 0.2mm, ensuring smooth assembly of the missile wings. This solves the technological problem of accurately ensuring thin wall thickness using CNC machining, giving full play to the advantages of CNC machining, reducing the workload of 3 hours of manual grinding for each product, reducing labor intensity, and improving production efficiency and product quality.

Claims

1. A method for processing a missile wing assembly bracket, characterized in that... The steps are as follows: On the platform, the center line of the missile casing is aligned by diameter, and machining allowance is left for each wing. Two circumferential reference lines, 0° and 180°, are drawn at the generatrix position. The missile casing is horizontally clamped in the CNC milling machine to control the runout of the outer circles at both ends of the missile casing within the design range, and to ensure that the axis of the missile casing is consistent with the rotation axis of the CNC milling machine. The runout of the outer circles at both ends should be controlled within the design range of 0.1~0.2mm to be considered horizontal; Within the generatrix length range after the wing is to be installed at 0° and 180°, the highest point of the shell is determined as the radial machining reference for the wing mounting bracket to ensure that there is no interference between the wing and the shell during assembly. The end face of the missile casing is used as the axial machining reference. The drawn circumferential reference line is used as the circumferential machining reference for CNC milling; the circumferential reference line must ensure the allowance of each machining surface in the design drawing; This provides the circumferential, radial, and axial machining references for machining the wing mounting brackets on the missile casing. The CNC milling machine's milling cutter side edge contacts the machining surface, and each wing mounting bracket on one side is machined according to the following steps, then rotated 180° to machine each wing mounting bracket on the other side: Step 1) Machin the radial height dimension to the finishing height dimension indicated on the drawing; Step 2) Perform semi-finishing in the radial direction, then finish machining, so that the upper half of the radial height direction of the missile wing mounting bracket is in place by 1 / 2 to 1 / 3 of the dimension, while retaining the lower half to ensure the rigidity of the machined part and eliminate tool deflection and chatter; Step 3) Perform semi-finish machining on the lower half of the missile wing mounting bracket in the radial height direction using a cutting motion in the radial direction; Step 4) Perform radial-direction finishing machining on the lower half of the missile wing mounting bracket to the required dimensions in the radial height direction; Finally, the mounting holes are machined.

2. The processing method of the missile wing assembly bracket according to claim 1, characterized in that: The circumferential reference line takes into account the margin of multiple wing mounting brackets on both sides, and two circumferential reference lines are drawn at 0° and 180° on the outer circle.

3. The processing method of the missile wing assembly bracket according to claim 1, characterized in that: The tool path is rectangular.

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