A method of machining a landing gear strut

Abstract

The application provides a landing gear support rod processing method. The landing gear support rod processing method comprises the following steps: providing a workpiece and a tooling for clamping the workpiece; clamping the workpiece by using the tooling; respectively rough machining an A-side surface of the workpiece in a Y direction, fine machining at least three reference surfaces on two process clamps, rough machining a B-side surface of the workpiece in the Y direction, fine machining the A-side surface of the workpiece, fine machining the B-side surface of the workpiece, fine finishing the reference surfaces parallel to an X direction, milling the reference surfaces parallel to the X direction into bevels, processing oil nozzles, positioning an ear of the workpiece, and removing the process clamps; polishing positions of the process clamps on the workpiece, and completing the processing. The application can realize concentrated processing of all processes by using the clamping positions reserved by the process clamps and cooperating with the tooling, all processes can be completed by the vertical machining center, the problem of process dispersion is solved, and the part transfer and auxiliary time are reduced.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and in particular to a method for machining landing gear struts. Background Technology

[0002] like Figure 1 As shown, the miniature landing gear strut 15 includes lugs 151 at both ends in the X direction. Each lug 151 has a through hole 152. A first grease nipple 135 is located at the root of one lug 151, and a second grease nipple 135 is located at the root of the other lug 151. The miniature landing gear strut 15 has high-precision structural features on all four sides. The selected machining method involves first preparing the workpiece surface, leaving pre-reserved pressure plate positions, then clamping it to the pre-reserved pressure plate positions using pressure plates, pressing it onto a worktable, and then using a combination of vertical and horizontal machining centers for machining. Multiple flipping is required during the machining process. Finally, manual grinding and polishing by a fitter are necessary. Clearly, this machining method requires repeated clamping of the workpiece during processing, which easily leads to clamping errors, making it difficult to guarantee the dimensional accuracy of the part, and resulting in multiple tool joints.

[0003] Furthermore, due to the small size of the part and its numerous corners, small-diameter tools are required for corner clearing. Because of the pressure plate, extended tools are needed to avoid tool interference. The pressure plate is typically 20mm-30mm thick; extending the tool reduces its rigidity, making it prone to vibration during machining and resulting in poor surface finish. Moreover, the longer tool necessitates a reduction in cutting speed, leading to decreased machining efficiency.

[0004] Furthermore, the workpiece is clamped and held in place using a pressure plate. During the clamping process, it needs to be repeatedly straightened, and finally, the oil nozzle needs to be laid flat. This disperses the process and increases the time spent on workpiece transfer and auxiliary operations. Summary of the Invention

[0005] The purpose of this invention is to provide a method for processing landing gear struts, which solves the problem of dispersed processes and improves processing efficiency.

[0006] The technical solution of this invention is: a method for processing landing gear struts, comprising the following steps:

[0007] Step 1: Provide a workpiece and a fixture for clamping the workpiece. The workpiece has lugs at both ends in the X direction, and through holes are provided in the lugs. An oil nozzle is provided at the root of the lugs. Install a process chuck in the through holes. The process chuck has at least three reference surfaces, two of which are parallel to the X direction and the remaining reference surfaces are parallel to the Z direction.

[0008] Step 2: Use tooling to clamp the workpiece, perform rough machining on the A-side surface of the workpiece in the Y direction, and perform finish machining on at least three reference surfaces on the two process chucks respectively.

[0009] Step 3: Disassemble the workpiece clamping from Step 2 and clamp the reference surface parallel to the X direction; rotate the workpiece 180° around the X axis and rough machine the B side surface of the workpiece in the Y direction.

[0010] Step 4: Rotate the workpiece 180° around the X-axis again to finish machine the surface of side A of the workpiece; after completion, rotate the workpiece 180° around the X-axis again to finish machine the surface of side B of the workpiece.

[0011] Step 5: Disassemble the clamping device from Step 3, clamp the reference surface parallel to the Z direction, rotate the workpiece 90° and 270° around the X axis respectively, and finish the reference surface parallel to the X direction.

[0012] Step 6: Rotate the workpiece 90° and 270° around the X-axis respectively, and mill the reference surface parallel to the X-direction into an inclined surface;

[0013] Step 7: Disassemble the clamping device on one end of the process chuck, and use a bevel on this end of the process chuck as a positioning device. Place a pad block below it so that the oil nozzle on the other end of the process chuck is placed within the machining range. A pressure block is provided on the bevel, and the pressure block and the pad block are located on the same process chuck and respectively correspond to the two bevels of the process chuck. The pad block is clamped, and the oil nozzle placed within the machining range is machined. The oil nozzle on the other end is machined in the same way.

[0014] Step 8: Disassemble the clamping device from Step 7, position the workpiece's lugs, and remove the process chuck;

[0015] Step nine: Grind the position of the process chuck on the workpiece to complete the machining.

[0016] Preferably, in step five, the parallelism of the refined reference plane parallel to the X direction is within 0.03 mm, and the perpendicularity to the reference plane parallel to the Z direction is controlled within 0.05 mm.

[0017] Preferably, after step five is completed, pressure gauge testing is performed on the reference surface in the X direction, and each reference surface is divided into three regions, with pressure gauges installed in each region. If the parallelism deformation exceeds 0.03 mm, step five is repeated.

[0018] Preferably, in step five, when machining one side of the reference surface, a pad is provided to support the other side of the reference surface.

[0019] Preferably, the width of the tooling clamping reference surface should be greater than or equal to 8mm.

[0020] Preferably, in step six, a ball-end milling cutter is used to finish the inclined surface with a step size of 0.25 mm and an accuracy of 0.01 mm.

[0021] Preferably, after step six is ​​completed, the machined bevel is perpendicular to the axis of the nozzle.

[0022] Preferably, in step seven, a vertical machining center is used to process the oil nozzle, and the pad used makes the axis of the oil nozzle to be processed parallel to the Z-axis of the vertical machining center.

[0023] Preferably, in step seven, a pressure block is provided on the inclined surface, and the pressure block and the pad block are located on the same process chuck and respectively correspond to the two inclined surfaces of the process chuck.

[0024] Compared with related technologies, the beneficial effects of the present invention are as follows:

[0025] I. This invention replaces the pressure plate with a process chuck on the workpiece, transforming the clamping of the workpiece surface into the clamping of the process chuck. During machining, there is no need to consider the interference and avoidance between the tool and the pressure plate, reducing the tool length, ensuring tool rigidity, increasing cutting speed, and reducing vibration during the cutting process, thereby improving tool durability and part surface quality. With the right tooling, it can achieve centralized machining of all processes (all can be completed through a vertical machining center) without the need for a pressure plate.

[0026] Second, this invention, through the clamping position reserved by the process chuck and in conjunction with tooling, can realize centralized processing of all processes (all processes can be completed by a vertical machining center), solving the problem of dispersed processes and reducing part transfer and auxiliary time;

[0027] Third, the process chuck is modified by anti-corrosion measures interspersed in each process to meet the clamping status and accuracy requirements of each process for the parts.

[0028] Fourth, this invention can achieve efficient machining of small landing gear struts, solving the problems of scattered processes, long clamping time, large tool length-to-diameter ratio, and low machining efficiency in such typical parts. It has strong promotion and reference value. Attached Figure Description

[0029] Figure 1 This is a structural schematic diagram of the landing gear strut;

[0030] Figure 2 for Figure 1 A top-view structural diagram;

[0031] Figure 3 This is a schematic diagram showing the connection between the workpiece and the process chuck before the landing gear strut is machined.

[0032] Figure 4 for Figure 3 A schematic diagram showing the formation of an inclined plane during machining;

[0033] Figure 5 This is a schematic diagram of the oil nozzle machining process. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" used below only indicate that they correspond to the upper, lower, left, and right directions in the accompanying drawings and do not limit the structure.

[0035] The method for processing a landing gear strut provided in this embodiment includes the following steps:

[0036] Step 1: Provide workpiece 13 and tooling for clamping workpiece 15, such as... Figure 3 As shown, the workpiece 13 has lugs 151 at both ends in the X direction, each lug 151 having a through hole 152. One lug 151 has a first grease nipple 135 at its root, and the other lug 151 has a second grease nipple 136 at its root. Figure 3 As shown, a process chuck 14 is installed in the through hole 152. One process chuck 14 has a first reference surface 141, a third reference surface 143, and a fifth reference surface 145. The other process chuck 14 has a second reference surface 142, a fourth reference surface 144, and a sixth reference surface 146. The first reference surface 141, the third reference surface 143, the second reference surface 142, and the fourth reference surface 144 are all defined as reference surfaces parallel to the X direction. The fifth reference surface 145, which connects the first reference surface 141 and the third reference surface 143, and the sixth reference surface 146, which connects the second reference surface 142 and the fourth reference surface 144, are defined as reference surfaces parallel to the Z direction. A suitable tooling, specifically a vise, is selected based on the size of the workpiece 13.

[0037] Step two, use a vise bracket to clamp the workpiece 3 with a clamping length of 8mm, and select a suitable pad to clamp the workpiece on the A-side surface in the Y direction (e.g., Figure 2 (As shown) rough machining is performed, and the first reference surface 141, the second reference surface 142, the third reference surface 143, the fourth reference surface 144, the fifth reference surface 145 and the sixth reference surface 146 on the two process chucks 14 are respectively finely machined.

[0038] Step 3: Disassemble the workpiece 13 from Step 2, clamp the first reference surface 141, the second reference surface 142, the third reference surface 143, and the fourth reference surface 144, rotate the workpiece 180° around the X-axis, with the fifth reference surface 145 and the sixth reference surface 146 facing downwards, and support it; rough machine the B-side surface of the workpiece 13 in the Y direction (e.g., Figure 2 (As shown).

[0039] In steps two and three, the safety distance of the CNC program should be greater than 20mm of the workpiece chuck, and the safety clamping length of the tool should ensure that the gap between the tool holder and the workpiece is greater than 2mm.

[0040] Step 4: Rotate the workpiece 180° around the X-axis again to finish the surface of side A of the workpiece; after that, rotate the workpiece 180° around the X-axis again to finish the surface of side B of the workpiece.

[0041] Step 5: Disassemble the clamping assembly from Step 3, clamping the fifth datum surface 145 and the sixth datum surface 146. Rotate workpiece 13 around the X-axis by 90° and 270° in two steps. The first step supports the third datum surface 143 and the fourth datum surface 144; the second step supports the first datum surface 141 and the second datum surface 142. Repeatedly refine the first datum surface 141, the second datum surface 142, the third datum surface 143, and the fourth datum surface 144, removing 0.5mm of excess material from each side to ensure parallelism of the four surfaces is within 0.03mm, and perpendicularity of the four datum surfaces to the fifth datum surface 145 and the sixth datum surface 146 is within 0.05mm. Simultaneously machine the C-side and D-side surfaces of workpiece 13 (e.g., ...). Figure 3 (As shown).

[0042] To refine a reference surface, a right-angle ruler and feeler gauge can be used in conjunction with a marble platform for verification. For easily deformable materials, the reference surface can be corrected by repeatedly refining it.

[0043] Step Six: Disassemble the clamps of the fifth datum surface 145 and the sixth datum surface 146, and clamp the first datum surface 141, the second datum surface 142, the third datum surface 143, and the fourth datum surface 144. During clamping, apply pressure gauges at three points (left, center, and right) on each datum surface. After clamping and securing, observe whether the differences between the three gauges are consistent. If the difference between the three gauge values ​​exceeds 0.03mm during clamping, repeat all machining operations in Step Five and readjust the datums. If the deformation meets the requirements, machine the surface of the through hole 152 of the workpiece 13.

[0044] Step 7: Disassemble the clamping device from Step 6, such as... Figure 4As shown, the fifth reference surface 145 and the sixth reference surface 146 are clamped, and the workpiece 13 is rotated 90° and 270° around the X-axis respectively. The first reference surface 141 is milled into the first inclined surface 131, the second reference surface 142 into the second inclined surface 132, the third reference surface 143 into the third inclined surface 133, and the fourth reference surface 144 into the fourth inclined surface 134. The machined first inclined surface 131 and second inclined surface 132 are perpendicular to the axis of the second oil nozzle 136, and the third inclined surface 133 and fourth inclined surface 134 are perpendicular to the axis of the first oil nozzle 135. Each inclined surface should be finished using a ball end mill with a step size of 0.25 mm and an accuracy of 0.01 mm to ensure the precision of the inclined surface.

[0045] Step 8: Disassemble the clamping device on one end of the process chuck 14, and use the fourth inclined plane 134 as a positioning point. Place a pad block 138 below it to position the first oil nozzle 135 within the machining range. A pressure block is provided on the inclined plane, and the pressure block and the pad block are located on the same process chuck, respectively corresponding to the two inclined planes of the process chuck. Clamp the two sides of the pad block 138 and machine the first oil nozzle 135. Machine the second oil nozzle 136 using the same method. The bottom surface of the pad block 138 should be at the correct angle to the machined oil nozzle, which can be verified by checking the height difference between the two holes using a dial indicator.

[0046] Step nine: Disassemble the clamping device from step eight, position the lug 151 of workpiece 13, straighten the through hole 152 and end face, and remove the process chuck.

[0047] Step 10: Grind the space for the process chuck on workpiece 13, and polish and deburr the surface of workpiece 13. The machining is completed, resulting in the final product as shown. Figure 1 The landing gear strut 15 is shown.

[0048] The machining method of this invention is suitable for machining small landing gear struts that require smaller cutting tools and involve machining at multiple angles. It is particularly applicable to machining mating surfaces with precise dimensions. Through extensive testing and verification, this process method ensures the surface quality and accuracy of small landing gear struts, maintains a stable machining process, and achieves high machining efficiency. It solves the problems of low machining efficiency, fragmented processes, and poor surface quality in the machining of small landing gear torque arms.

[0049] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method of machining a landing gear strut, characterized in that, The method comprises the following steps: Step one, providing a workpiece and a tooling for clamping the workpiece, both ends of the workpiece in X direction are provided with lugs, the lugs are provided with through holes, the roots of the lugs are provided with oil nozzles; a process chuck is installed in the through holes; the process chuck is provided with at least three reference surfaces, two of which are parallel to the X direction, and the rest are parallel to the Z direction; Step two, clamping the workpiece by using the tooling, rough machining the A side surface of the workpiece in Y direction, and fine machining the at least three reference surfaces on the two process chucks respectively; Step three, disassembling the clamping of the workpiece in step two, clamping the reference surfaces parallel to the X direction; rotating the workpiece by 180° around the X axis, and rough machining the B side surface of the workpiece in Y direction; Step four, rotating the workpiece by 180° around the X axis again, fine machining the A side surface of the workpiece; after completion, rotating the workpiece by 180° around the X axis again, fine machining the B side surface of the workpiece; Step five, disassembling the clamping in step three, clamping the reference surfaces parallel to the Z direction, rotating the workpiece by 90° and 270° around the X axis respectively, and finishing the reference surfaces parallel to the X direction; Step six, rotating the workpiece by 90° and 270° around the X axis respectively, and milling the reference surfaces parallel to the X direction into bevels; Step seven, disassembling the clamping on the process chuck at one end, using one bevel on the process chuck at this end as a positioning, setting a pad block below the bevel, so that the oil nozzle on the process chuck at the other end is located in the machining range; setting a pressing block on the bevel, the pressing block and the pad block are located on the same process chuck, and the pad block is clamped corresponding to the two bevels of the process chuck, machining the oil nozzle located in the machining range; machining the oil nozzle at the other end by the above method; Step eight, disassembling the clamping in step seven, positioning the lug of the workpiece, and disassembling the process chuck; Step nine, polishing the position of the process chuck on the workpiece, and completing the machining.

2. The method of claim 1, wherein, In step five, the parallelism of the finished reference surfaces parallel to the X direction is within 0.03 mm, and the perpendicularity to the reference surfaces parallel to the Z direction is controlled within 0.05 mm.

3. The method of claim 2, wherein, After step five, the reference surfaces in the X direction are detected by a pressure gauge, and each reference surface is divided into three areas, each area is provided with a pressure gauge, if the parallelism deformation exceeds 0.03 mm, step five is repeated.

4. The method of claim 1, wherein, In step five, when machining one side reference surface, the other side reference surface is supported by a pad block.

5. The method of claim 1, wherein, The width of the tooling clamping reference surface should be greater than or equal to 8 mm.

6. The method of claim 1, wherein, In step six, a ball nose cutter is used to fine machine the bevel, the step distance is 0.25 mm, and the accuracy is 0.01 mm.

7. The method of claim 1, wherein, After step six, the machined bevel is perpendicular to the axis of the oil nozzle.

8. The method of claim 1, wherein, In step seven, the oil nozzle is machined by a vertical machining center, and the pad block is used to make the axis of the oil nozzle to be machined parallel to the Z axis of the vertical machining center.

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