A CNC machining method for beam parts

Abstract

The present invention discloses a CNC machining method for a beam component, comprising the following steps: inspection, surface finishing, rough milling, aging, surface finishing, and fine milling. During machining, the center portion of the I-shaped long beam groove is first machined, followed by the upper and lower inner walls of the groove, and finally the upper and lower outer walls. This method effectively resolves deformation issues, ensuring part finish and dimensional compliance. Furthermore, the machining process is converted from five-axis machining to three-axis machining, reducing machining costs. Furthermore, the surface finish of the profile machined by the PCD tool meets part requirements, eliminating the need for manual polishing and improving machining efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of numerical control processing technology for beam parts, and in particular to a tool for positioning and installing tile-shaped permanent magnet blocks. The beam part is especially an I-shaped long beam of an aircraft fuselage. Background Art

[0002] The I-shaped long crossbeam, a component of a certain aircraft fuselage, is a long, I-shaped structure. This part is prone to deformation after machining, making it difficult to meet design and assembly requirements for dimensional accuracy. Furthermore, the I-shaped structure requires left and right swing machining on a five-axis machine tool, which increases processing costs. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a CNC machining method for beam parts. The present invention aims to solve the problem of deformation during beam part machining and the high cost of five-axis machine tools through structural analysis of the beam. The present invention effectively solves the deformation problem, ensures the smoothness and dimensions of the parts, and converts the machining plan from five-axis machining to three-axis machining, reducing machining costs. The surface finish of the profile machined by the PCD tool meets the part requirements, eliminating the need for benchwork and polishing, thereby improving machining efficiency. The present invention can meet the design requirements of long beams for aircraft / aerospace parts and can be extended to the machining of other similar parts, showing broad application prospects.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A crossbeam part numerical control machining method comprises the following steps:

[0006] Step S1: The blank part is an I-shaped long beam part, and the beam blank is subjected to mechanical strength shear force testing, tensile stress testing and non-destructive testing;

[0007] Step S2: Pick up the I-shaped long crossbeam blank to be processed via the factory transport vehicle, and leave a 1mm margin / residual edge on the upper and lower sides for brushing to ensure a flatness of 0.1mm;

[0008] Step S3: A pressure plate is pressed against one side of the bottom wall of the I-shaped long crossbeam, and a D100R0T milling cutter is used to rough the groove with a 2mm allowance. The machining speed is 5000 n / min, the machining feed rate is 1500 mm / min, the radial cutting depth is 1mm, and the axial cutting depth is 12mm. During machining, the middle part of the groove of the I-shaped long crossbeam is first machined, and then the upper and lower inner walls of the groove are machined, and finally the upper and lower outer walls of the groove are machined, which can reduce stress derivatives.

[0009] Step S4: A pressure plate is placed in the machined groove, the pressure plate on the unmachined side is released, and the other side is roughened with a D100R0T milling cutter with a 2mm allowance; the machining speed is 5000 n / min, the machining feed rate is 1500 mm / min, the radial cutting depth is 1 mm, and the axial cutting depth is 12 mm; during machining, the middle part of the I-shaped long crossbeam groove is machined first, then the upper and lower inner walls of the groove are machined, and finally the upper and lower outer walls of the groove are machined, which can reduce stress derivatives;

[0010] Step S5: natural aging for 24 hours to remove processing stress;

[0011] Step S6: Brush the surface evenly to remove the 1mm margin reserved on the upper and lower surfaces to ensure thickness, flatness and parallelism;

[0012] Step S7: Center the part vertically and horizontally, press the pressure plate into the groove on one side, and use the D80R3PCD solid milling cutter to machine the groove. The speed is 3200 n / min, the feed rate is 770 mm / min, the radial cutting depth is 0.3, and the axial cutting depth is 9 mm, which can effectively ensure the surface finish and thickness of the part. Figure 2 As shown in the figure; during processing, the middle part of the I-shaped long crossbeam groove is processed first, then the upper and lower inner wall surfaces of the groove are processed, and finally the upper and lower outer wall surfaces of the groove are processed, which can reduce stress derivatives;

[0013] Step S8: Place support blocks every 350 mm in the milled groove to ensure machining strength and prevent part vibration during machining due to thin wall thickness; add pressure plates to press on the support blocks and stagger the pressure plates between the two support blocks to prevent the part from being pressed and lifted; loosen the pressure plates in the unmachined groove and use the D80R3PCD integral milling cutter to machine the groove;

[0014] Step S9: Detecting the dimensional accuracy, flatness, and parallelism of the I-shaped long crossbeam parts.

[0015] Furthermore, the D100R0T milling cutter is a roughing T-type milling cutter with replaceable blades, a tool diameter of 100, a tool R angle of R0, a blade length of 15, a shank diameter of 25, and a tool length of 100; the D80R3PCD integral finishing milling cutter is an integral finishing T-type milling cutter with PCD blades, a tool diameter of 80, a tool R angle of R3, a blade length of 15, a shank diameter of 25, and a tool length of 100.

[0016] Furthermore, the groove depth of the part is 21mm calculated from the narrower plane, and is 50.5mm calculated from the wider plane. The R angles of the upper and lower surfaces are R3. Two T-shaped tools are designed based on the analysis of the beam structure, and the inner surface of the I-shaped groove of the part is processed by the T-shaped milling cutter in conjunction with the three-axis machine tool.

[0017] Furthermore, the support block is used to be embedded in the groove during fine milling, and the support block includes a first support block, an adjusting block, a bolt, and a nut. The vertical side walls of the first support block fit with the vertical side walls of the I-shaped long crossbeam, and the bottom side walls fit with the bottom side walls of the I-shaped long crossbeam groove. The upper surface of the upper cross wall of the first support block is connected with the adjusting block, and the other side surface of the adjusting block abuts the upper side wall of the groove. The adjusting block is connected to the upper cross wall of the first support block by a bolt, and the lower end surface of the upper cross wall is connected with a nut; the support height of the support block can be adjusted by the design of the adjusting block, bolt, and nut to meet the needs of I-shaped long crossbeam grooves of various sizes.

[0018] Furthermore, the I-shaped long crossbeam part is an aircraft fuselage crossbeam. The part is 3000mm long, with a wall thickness of only 3mm, and the blank removal rate reaches more than 90%.

[0019] The present invention provides a CNC machining method for beam components, effectively resolving deformation issues and ensuring component finish and dimensional compliance. The method also reduces costs by switching from five-axis machining to three-axis machining. The surface finish of the profile machined with PCD tools meets component requirements, eliminating the need for manual polishing and improving machining efficiency. This method can meet the design requirements of long beams for aircraft and aviation components and can be extended to the machining of other similar components, demonstrating its broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the rough machining path of the D100T milling cutter of the present invention;

[0021] Figure 2 This is a schematic diagram of the finishing path of the D80R3T milling cutter of the present invention;

[0022] Figure 3 This is a schematic diagram of the support block and pressure plate structure of the present invention;

[0023] Figure 4 This is a schematic diagram of the present invention where the support block supports the machined groove and then finish mills the groove on the other side;

[0024] Figure 5 This is a schematic diagram of the support block structure of the present invention.

[0025] In the figure: first support block 1, adjustment block 2, bolt / screw 3, nut 4, pressure plate 5, support block 6, I-shaped long crossbeam 7, groove 8. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] The present invention will be described in further detail below with reference to the accompanying drawings.

[0028] like Figure 1-5 As shown, a CNC machining method for a beam part comprises the following steps:

[0029] Step S1: The blank part is an I-shaped long beam part, and the beam blank is subjected to mechanical strength shear force testing, tensile stress testing and non-destructive testing;

[0030] Step S2: Pick up the I-shaped long crossbeam blank to be processed via the factory transport vehicle, and leave a 1mm margin / residual edge on the upper and lower sides for brushing to ensure a flatness of 0.1mm;

[0031] Step S3: The pressure plate presses one side of the bottom wall of the I-shaped long horizontal beam, and a D100R0T milling cutter is used to leave a 2mm allowance for roughing (rough milling). The speed during processing is 5000 n / min, the processing feed rate is 1500mm / min, the radial cutting depth is 1mm, and the axial cutting depth is 12mm. During processing, the middle part of the I-shaped long horizontal beam groove is processed first, and then the upper and lower inner wall surfaces of the groove are processed, and finally the upper and lower outer wall surfaces (vertical surfaces) of the groove are processed, which can reduce / prevent stress derivation, such as Figure 1 As shown;

[0032] Step S4: A pressure plate is placed in the machined groove, the pressure plate on the unmachined side is released, and the other side is roughened with a D100R0T milling cutter with a 2mm allowance. The machining speed is 5000 n / min, the machining feed rate is 1500 mm / min, the radial cutting depth is 1 mm, and the axial cutting depth is 12 mm. During machining, the middle portion of the I-shaped long crossbeam groove is machined first, followed by the upper and lower inner walls of the groove, and finally the upper and lower outer walls (vertical surfaces) of the groove, which can reduce / prevent stress generation.

[0033] Step S5: natural aging for 24 hours to remove processing stress;

[0034] Step S6: Brush the surface evenly to remove the 1mm margin reserved on the upper and lower surfaces to ensure thickness, flatness and parallelism;

[0035] Step S7: Center the part vertically and horizontally, press the pressure plate into the groove on one side, and use the D80R3PCD solid milling cutter to machine the groove. The speed is 3200 n / min, the feed rate is 770 mm / min, the radial cutting depth is 0.3, and the axial cutting depth is 9 mm, which can effectively ensure the surface finish and thickness of the part. Figure 2 As shown in the figure; during processing, the middle part of the I-shaped long crossbeam groove is processed first, then the upper and lower inner wall surfaces of the groove are processed, and finally the upper and lower outer wall surfaces (vertical surfaces) of the groove are processed, which can reduce / prevent stress derivation;

[0036] Step S8: Place support blocks every 350mm in the milled groove to ensure the processing strength and prevent the parts from vibrating during processing due to the thin wall thickness; add pressure plates to press on the support blocks and staggered clamping plates in the area between the two support blocks to prevent the parts from being pressed and warped (such as Figure 3 As shown), loosen the inner pressure plate of the unmachined groove and use the D80R3PCD solid milling cutter to machine the groove, as shown Figure 4 As shown;

[0037] Step S9: Detecting the dimensional accuracy, flatness, and parallelism of the I-shaped long crossbeam parts.

[0038] In the present invention, according to the analysis of the appearance of the I-shaped long crossbeam part, the length is relatively long, reaching 3000mm, and the wall thickness is only 3mm, and the appearance is I-shaped, the middle vertical rib is very easy to deform, and the blank removal rate is relatively large, reaching more than 90%. The part is added with roughing (rough milling), aging stress relief, and secondary brushing processes to ensure that the dimensional accuracy of the part is qualified.

[0039] This part has an I-shaped structure and is usually machined using five-axis swing angle machining. To save machining costs, the part structure was analyzed. The groove depth of the part is 21mm calculated from the narrow plane and 50.5mm calculated from the wide plane. The R angle of the upper and lower surfaces is R3. Two T-shaped cutters were designed based on the crossbeam structure analysis. The T-shaped milling cutters are used in conjunction with a three-axis machine tool to machine the inner surface of the I-shaped groove of the part. Since the surface finish of the part is relatively high, PCD cutters are used for fine milling to effectively ensure the surface finish of the part.

[0040] The D100R0T milling cutter is a roughing T-type milling cutter with replaceable inserts, which has a tool diameter of 100, a tool R angle of R0, a blade length of 15, a shank diameter of 25, and a tool length of 100. The D80R3PCD integral finishing milling cutter is an integral finishing T-type milling cutter with PCD inserts, which has a tool diameter of 80, a tool R angle of R3, a blade length of 15, a shank diameter of 25, and a tool length of 100.

[0041] In order to ensure the thickness and processing strength of the parts, a special support block is designed and inserted into the groove during fine milling to effectively ensure the thickness and strength of the parts.

[0042] like Figure 5 As shown, in one embodiment, a support block is used to be embedded in a groove during fine milling. The support block includes a first support block, an adjustment block, a bolt / screw, and a nut. The vertical sidewalls of the first support block are aligned with the vertical sidewalls of the I-shaped long crossbeam, and the bottom sidewall is aligned with the bottom sidewall of the I-shaped long crossbeam groove. The upper surface of the upper crosswall of the first support block is connected to the adjustment block, and the other side of the adjustment block abuts the upper sidewall of the groove. The adjustment block is connected to the upper crosswall of the first support block by one or more bolts, and the lower end surface of the upper crosswall is connected to the nut. The present invention can adjust the support height of the support block by arranging the adjustment block, bolts, and nuts to meet the needs of various sizes of I-shaped long crossbeam grooves, and has strong applicability and low cost.

[0043] The present invention provides a CNC machining method for beam components, effectively resolving deformation issues and ensuring component finish and dimensional compliance. The method also reduces costs by switching from five-axis machining to three-axis machining. The surface finish of the profile machined with PCD tools meets component requirements, eliminating the need for manual polishing and improving machining efficiency. This method can meet the design requirements of long beams for aircraft and aviation components and can be extended to the machining of other similar components, demonstrating its broad application prospects.

[0044] The above-mentioned embodiments are illustrative of the present invention, not limiting thereof. It is understood that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A CNC machining method for a beam part, comprising the following steps: Step S1: The blank part is an I-shaped long beam part, and the blank is subjected to mechanical strength shear force testing, tensile stress testing and non-destructive testing; Step S2: Pick up the I-shaped long crossbeam blank to be processed via the factory transport vehicle, and leave a 1mm margin / residual edge on the upper and lower sides for brushing to ensure a flatness of 0.1mm; Step S3: A pressure plate is pressed against one side of the bottom wall of the I-shaped long crossbeam, and a D100R0T milling cutter is used to rough the groove with a 2mm allowance. The machining speed is 5000 n / min, the machining feed rate is 1500 mm / min, the radial cutting depth is 1mm, and the axial cutting depth is 12mm. During machining, the middle part of the groove of the I-shaped long crossbeam is first machined, and then the upper and lower inner walls of the groove are machined, and finally the upper and lower outer walls of the groove are machined, which can reduce stress derivatives. Step S4: A pressure plate is placed in the machined groove, the pressure plate on the unmachined side is released, and the other side is roughened with a D100R0T milling cutter with a 2mm allowance; the machining speed is 5000 n / min, the machining feed rate is 1500 mm / min, the radial cutting depth is 1 mm, and the axial cutting depth is 12 mm; during machining, the middle part of the I-shaped long crossbeam groove is machined first, then the upper and lower inner walls of the groove are machined, and finally the upper and lower outer walls of the groove are machined, which can reduce stress derivatives; Step S5: natural aging for 24 hours to remove processing stress; Step S6: Brush the surface evenly to remove the 1mm margin reserved on the upper and lower surfaces to ensure thickness, flatness and parallelism; Step S7: Center the part vertically and horizontally, press the pressure plate into the groove on one side, and use a D80R3PCD solid milling cutter to machine the groove. The speed is 3200 n / min, the feed rate is 770 mm / min, the radial depth of cut is 0.3 mm, and the axial depth of cut is 9 mm. This effectively ensures the surface finish and thickness of the part. During machining, the middle part of the I-shaped long crossbeam groove is machined first, followed by the upper and lower inner walls of the groove, and finally the upper and lower outer walls of the groove, which can reduce stress derivatives. Step S8: Place support blocks every 350 mm in the milled groove to ensure machining strength and prevent part vibration during machining due to thin wall thickness; add pressure plates to press on the support blocks and stagger the pressure plates between the two support blocks to prevent the part from being pressed and lifted; loosen the pressure plates in the unmachined groove and use the D80R3PCD integral milling cutter to machine the groove; Step S9: Detecting the dimensional accuracy, flatness, and parallelism of the I-shaped long crossbeam parts.

2. A CNC machining method for a beam part according to claim 1, characterized in that: The support block is used to be embedded in the groove during fine milling. The support block includes a first support block (1), an adjusting block (2), a bolt (3), and a nut (4). The vertical side wall of the first support block fits with the vertical side wall of the I-shaped long crossbeam, and the bottom side wall fits with the bottom side wall of the I-shaped long crossbeam groove. The upper surface of the upper cross wall of the first support block is connected with the adjusting block, and the other side surface of the adjusting block abuts against the upper side wall of the groove. The adjusting block is connected to the upper cross wall of the first support block through a bolt, and the lower end surface of the upper cross wall is connected with a nut. The support height of the support block is adjusted by designing the adjusting block, the bolt, and the nut to meet the needs of I-shaped long crossbeam grooves of various sizes.

3. A CNC machining method for a beam part according to claim 2, characterized in that: This I-shaped long crossbeam part is an aircraft fuselage crossbeam. The part is 3000mm long, with a wall thickness of only 3mm, and the blank removal rate reaches over 90%.

Images