Method for machining combustion header pipe mounting seat of afterburner of aero-engine of certain model
Through precise positioning and multi-step processing methods, combined with improved clamping tools, the problem of maintenance difficulties of combustion main pipe mounts is solved, and high-precision and low-cost processing effects are achieved.
Patent Information
- Application Number
- CN202510882715.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-28
- Publication Date
- 2025-09-02
AI Technical Summary
The combustion main tube mount of a certain model of aircraft engine is difficult to repair or repair after damage, and due to irregular shapes, it is difficult to effectively position and clamp, which leads to processing difficulties.
The CNC lathe and CNC machining center are combined with centering chucks, lever dial tables and other tools. Through precise positioning and multi-step processing, the processing of the combustion main pipe mount is gradually completed, including processing process holes, threads, conical surfaces and shapes. The improved hexagon bolts and process plates are used for stable clamping to avoid secondary clamping errors.
It realizes high-precision combustion main pipe mounting seat processing, meets the usage requirements, reduces maintenance costs, improves processing efficiency and positioning accuracy, and avoids processing problems caused by positioning errors.
Smart Images
Figure CN120572276A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of aero-engines, and in particular to a method for machining a combustion manifold mounting seat of an afterburner chamber of a certain type of aero-engine. Background Art
[0002] The afterburner combustion manifold mounting bracket is a crucial component of the afterburner, and its installation and design are directly related to the afterburner's performance and reliability. The afterburner combustion manifold mounting bracket's primary function is to secure and support the afterburner's combustion manifold, ensuring its stability in high-speed airflow and high-temperature environments. The mounting bracket must also ensure a tight seal between the combustion manifold and other afterburner components to prevent gas leakage and ensure smooth flow of fuel and air into the combustion manifold. Because the afterburner operates at extremely high temperatures, the mounting bracket is typically made of a high-temperature-resistant alloy to withstand the thermal stress and thermal deformation of high-temperature environments. The mounting bracket requires high machining precision to ensure accurate fit with the combustion manifold and other components, minimizing airflow loss and vibration. The structural design of the mounting bracket must be optimized based on factors such as airflow characteristics, thermal stress distribution, and ease of maintenance.
[0003] Furthermore, the material used for the combustion manifold mounting bracket in the afterburner of a key aircraft engine is GH3044. Due to its irregular shape and structure, it must be cast. When this part becomes damaged and requires repair, casting is prohibitively expensive. Machining this part is difficult due to its irregular shape and lack of positioning references and clamping points. This means that conventional fixtures such as flat-nose pliers and three-jaw self-centering chucks cannot accurately position and clamp the part, making it difficult to manufacture. Positioning and clamping the part during machining is a key issue that needs to be addressed. Summary of the Invention
[0004] To address the difficulty or high cost of repairing a damaged combustion manifold mounting bracket for a certain type of aircraft engine afterburner, the present invention provides a method for machining a combustion manifold mounting bracket for a certain type of aircraft engine afterburner. The resulting mounting bracket, manufactured using this method, exhibits high precision and fully meets operational requirements. If the mounting bracket is damaged, it can be replaced by casting, thus resolving the technical issue of inconvenient repair of the damaged mounting bracket.
[0005] In order to achieve the above-mentioned object, the present invention adopts the following technical solution: a method for processing a combustion manifold mounting seat of an afterburner of a certain type of aircraft engine, comprising the steps of: S1: Process a Ø12 process hole on the finished blank to serve as the alignment reference for the next process; S2: Clamp the workpiece with the Ø12 process hole on the four-jaw centering chuck of the CNC lathe. Use a lever dial indicator to align the workpiece so that the axis of the Ø12 process hole is coaxial with the axis of the CNC lathe spindle, with an error within 0.02 mm. Then, according to the drawing requirements, turn the Ø12 process hole to Ø16, and process the taper surface, thread, and thread undercut. S4: Mount the workpiece on a CNC machining center with a flat-nose vise, machine a Ø12 process hole in the middle of the base and three evenly spaced Ø6.8 holes, then use a tap to thread the Ø6.8 holes into M8 threaded holes. S4: Processing a process plug and installing the process plug on the external thread of the workpiece, wherein the internal thread of the process plug matches the external thread of the workpiece; S5: Then clamp the workpiece on the four-jaw centering chuck of the CNC lathe, and use a lever dial indicator to align the workpiece so that the axis of the Ø12 process hole in the base is coaxial with the axis of the CNC lathe spindle, with an error within 0.02mm; S6: After the clamping is completed, the Ø12 process hole is turned to Ø16, and the hole taper is turned. After the processing is completed, the workpiece is removed and the process plug is removed; S7: Make a process plate. Process three Ø8.2 countersunk holes on the bottom of the process plate. The hole positions match the workpiece. Process a Ø16 cylindrical boss and two M8 threaded holes in the center of the top of the process plate. The Ø16 holes on the bottom of the workpiece match the Ø16 cylindrical boss on the process plate. S8: Use three M8 hexagon socket bolts to fix the workpiece to the process board; S9: Install the process plate with the workpiece on the workbench of the CNC machining center, and then process the base shape, the arc surface above the base and the transition fillet according to the drawing requirements; S10: Install two pressing plates above the workpiece and press the workpiece with two M8 hexagon socket bolts. Then remove the three M8 hexagon socket bolts below the process plate. Then expand the three M8 threaded holes above the workpiece base to Ø8.2. Complete the processing to obtain the finished workpiece.
[0006] Preferably, the bottom surfaces of the screw rods of the three M8 hexagon socket bolts have square holes.
[0007] Preferably, regular hexagonal square holes are punched out on the bottom surface of the screw by electric spark, and the distance between the hexagons is 5 mm.
[0008] A combustion manifold mounting seat for an afterburner of a certain type of aircraft engine is machined according to the machining method.
[0009] The present invention has the following beneficial effects: (1) Change the three Ø8.2 through holes on the triangular base of the part into M8 threaded holes, fix the workpiece to the tooling plate with three hexagonal bolts, and then expand the M8 threaded holes to Ø8.2 by milling to meet the clamping requirements of the workpiece; (2) Use CNC spark machine to process the end face of the hexagonal socket bolt into a hexagonal hole with a distance of 4 mm. After the workpiece is milled, two pressure plates are pressed on the tooling plate. The hexagonal socket bolt can be removed without removing the process plate from the three-jaw self-centering chuck (the hole can be expanded after it is removed) to avoid positioning errors caused by secondary clamping; (3) The process plate adopts a circular structure to facilitate positioning and clamping. A short cylindrical boss is designed on the top of the process plate to avoid over-positioning. The process plate limits the freedom of rotation around the X and Y axes and the freedom of movement along the Z axis. The short cylindrical boss limits the freedom of movement in the X and Y directions. There is no over-positioning. The rotation around the Z axis is determined by aligning the dial indicator. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 This is a structural diagram of the combustion chamber combustion main pipe mounting base; Figure 2 It is a structural diagram of the fine blank; Figure 3 This is a schematic diagram of installing the fine blank on the CNC machining center; Figure 4 Schematic diagram of the inner hole, thread undercut, thread and tapered surface machined on the finished blank; Figure 5 This is a schematic diagram of the middle Ø12 process hole and 3*M8 threaded bottom holes (Ø6.8) machined on the fine blank; Figure 6 It is a structural diagram of the process plug; Figure 7 This is a schematic diagram of the process plug installed on the fine blank thread; Figure 8 This is a schematic diagram of the fine blank after the process plug is installed on the four-jaw centering chuck of the CNC lathe; Figure 9 Schematic diagram of the inner hole and the taper surface of the hole machined on the fine blank; Figure 10 This is a schematic diagram of the front and back structures of the process board; Figure 11 This is a schematic diagram of the fine blank being fixed on the process board; Figure 12 This is a schematic diagram of the fine blank being fixed on the process plate mounted on a three-jaw self-centering chuck; Figure 13 This is a schematic diagram of the triangular base, the arc surface above the base, and the transition fillet machined on the fine blank; Figure 14 A schematic diagram of installing two pressure plates; Figure 15 Schematic diagram for unscrewing the hexagon socket screw; Figure 16 This is a schematic diagram after the hexagon socket screw is unscrewed; Figure 17 This is a schematic diagram of the structure of an improved hexagon socket screw.
[0011] In the figure: 1. Fine blank; 2. Process hole for pipe; 3. Four-jaw centering chuck for CNC lathe; 4. Through hole for pipe; 5. Tapered surface of pipe mouth; 6. Thread; 7. Thread undercut groove; 8. Process hole at bottom; 9. Smooth hole; 10. Process plug; 11. Tapered surface of hole mouth; 12. Through hole at bottom; 13. Countersunk hole; 14. Cylindrical boss; 15. Process plate; 16. M8 threaded hole; 17. Triangular base; 18. Pressing plate; 19. Hexagon socket bolt; 20. Improved hexagon socket screw; 21. Connecting pipe; 22. Three-jaw self-centering chuck; 23. Regular hexagonal square hole. DETAILED DESCRIPTION
[0012] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0013] like Figure 1 The illustrated mounting base for a combustion manifold of an afterburner chamber of a certain type of aircraft engine includes a triangular base 17 and a connecting pipe 21 in an integral structure. The connecting pipe 21 has an external thread 6, the triangular base 17 has a bottom through hole 12, and the connecting pipe 21 has a pipe through hole 4. The bottom through hole and the pipe through hole have the same diameter and are interconnected. The processing method thereof includes the following steps: S1: Install the finished blank (two sides are parallel and four sides are perpendicular to the two sides) on the CNC machining center with precision flat-nose pliers, and process a pipe process hole 2 with a diameter of Ø12 on the top of the blank (the hole diameter on the part is Ø16) for alignment in the next process. The Ø12 pipe process hole 2 is the alignment reference for the next process. The dimensions of the axis of the pipe process hole 2 and the side and bottom surfaces of the finished blank should be strictly controlled, such as Figure 2 、 Figure 3 As shown; S2: Install the finished blank with the Ø12 pipe process hole 2 on the four-jaw centering chuck of the CNC lathe, and use a lever dial indicator to align the Ø12 pipe process hole 2 so that the axis of the Ø12 pipe process hole 2 is coaxial with the axis of the CNC lathe spindle, with an error within 0.02mm; after the alignment is completed, process the pipe through hole 4, thread 6, thread undercut 7 and pipe nozzle tapered surface 5 according to the drawing requirements. After the processing is completed, remove the workpiece from the four-jaw centering chuck, as shown in the figure. Figure 4 、 Figure 5 ; S3: Mount the workpiece on the CNC machining center with a flat-nose pliers, and machine a Ø12 bottom process hole 8 (for alignment in the next process) and three evenly spaced Ø6.8 light holes 9. Then use a tap to tap the three Ø6.8 light holes 9 into three M8 threaded holes 16. Figure 5 As shown; S4: In order to avoid damaging the workpiece, a process plug 10 is processed on the CNC lathe. The internal thread of the process plug 10 matches the external thread 6 of the workpiece. The processed process plug 10 is installed on the workpiece to ensure the installation stability of the next process. Figure 6 、 Figure 7 As shown; S5: Install the workpiece on the four-jaw centering chuck 3 of the CNC lathe, and use the lever dial indicator to align the workpiece Ø12 bottom process hole 8, so that the axis of the bottom process hole 8 is coaxial with the axis of the lathe spindle, and the error is within 0.02mm. Figure 8 As shown; S6: After the clamping is completed, the bottom process hole 8 with a diameter of Ø12 is expanded into a bottom through hole 12 with a diameter of Ø16 and its hole taper 11. The hole taper 11 has a high precision requirement and needs to play a sealing role. It needs to be inspected by coloring. Directly milling it into roundness on a CNC machining center will result in an out-of-tolerance, so a CNC lathe must be used for processing. After processing, remove the workpiece from the four-jaw centering chuck and remove the process plug 10. Figure 9 As shown; S7: A self-made process plate 15 is made. Three Ø8.2 countersunk holes 13 are machined on the bottom surface of the process plate 15. The hole positions match the workpiece. A Ø16 cylindrical boss 14 and two M8 threaded holes 16 are machined at the center of the top surface of the process plate 15. The Ø16 bottom through hole 12 on the bottom surface of the workpiece matches the Ø16 cylindrical boss 14 on the process plate 15. Figure 10 As shown; S8: Use three M8 hexagon socket bolts 19 to fix the workpiece on the process plate 15, as shown in Figure 11 As shown; S9: Install the process plate 15 with the workpiece on top of the three-jaw self-centering chuck 22, and install the three-jaw self-centering chuck 22 on the workbench of the CNC machining center; then according to the requirements of the drawing, process the shape of the triangular base, the arc surface above the base, and the transition fillet, such as Figure 12 、 Figure 13 As shown; S10: After the processing is completed, install two pressing plates 18 on the top of the part. After the two pressing plates 18 are pressed, remove the three M8 hexagon socket bolts 19 (it is not necessary to remove the process plate 15 from the three-jaw self-centering chuck 22), and then expand the three M8 threaded holes 16 into three Ø8.2 countersunk holes 13. Finally, dismantle the finished workpiece, such as Figure 14 、 Figure 15 and Figure 16 shown.
[0014] like Figure 17 As shown, the three M8 hexagon socket head cap screws 19 have been improved: regular hexagonal square holes 23 have been electro-discharged on the bottom surfaces of the screws, with a hexagonal spacing of 5 mm. This improvement allows for the removal of the three M8 hexagon socket head cap screws 19 after the workpiece milling process without removing the process plate 15 from the three-jaw self-centering chuck 22, which would otherwise result in positioning errors during secondary clamping. Finally, all relevant dimensions are in millimeters.
[0015] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A method for processing a mounting seat of a combustion manifold of an afterburner chamber of a certain type of aircraft engine, characterized in that: Including steps: S1: Process a Ø12 process hole on the finished blank to serve as the alignment reference for the next process; S2: Clamp the workpiece with the Ø12 process hole on the four-jaw centering chuck of the CNC lathe. Use a lever dial indicator to align the workpiece so that the axis of the Ø12 process hole is coaxial with the axis of the CNC lathe spindle, with an error within 0.02mm. Then, expand the Ø12 process hole to a Ø16 inner hole according to the drawing requirements, and process the tapered surface, thread, and thread undercut. S3: Mount the workpiece on a CNC machining center with a flat-nose vise, machine a Ø12 process hole in the center of the base and three evenly spaced Ø6.8 holes, then use a tap to thread the Ø6.8 holes into M8 threaded holes. S4: Processing a process plug and installing the process plug on the external thread of the workpiece, wherein the internal thread of the process plug matches the external thread of the workpiece; S5: Then clamp the workpiece on the four-jaw centering chuck of the CNC lathe, so that the axis of the Ø12 process hole of the workpiece base is coaxial with the axis of the CNC lathe spindle, with an error within 0.02mm; S6: After the clamping is completed, the Ø12 process hole is turned to Ø16, and the hole taper is turned. After the processing is completed, the workpiece is removed and the process plug is removed; S7: Make a process plate. Process three Ø8.2 countersunk holes on the bottom of the process plate. The hole positions match the workpiece. Process a Ø16 cylindrical boss and two M8 threaded holes in the center of the top of the process plate. The Ø16 hole in the workpiece base matches the Ø16 cylindrical boss on the process plate. S8: Use three M8 hexagon socket bolts to fix the workpiece to the process board; S9: Install the process plate with the workpiece on the workbench of the CNC machining center, and then process the base shape of the workpiece, the arc surface above the base and the transition fillet according to the drawing requirements; S10: Install two pressing plates above the process plate and use M8 hexagon socket bolts to press the workpiece base. Then remove the three M8 hexagon socket bolts below the process plate, and then expand the three M8 threaded holes to Ø8.2 to complete the processing and obtain the finished workpiece.
2. The processing method according to claim 1, characterized in that: The bottom surfaces of the screw rods of the three M8 hexagon socket bolts are provided with square holes.
3. The processing method according to claim 2, characterized in that: A regular hexagonal square hole is punched out on the bottom surface of the screw by electric spark, and the distance between the hexagons is 5 mm.
4. A combustion manifold mounting seat for an afterburner of a certain type of aircraft engine processed by the processing method according to claim 1.