Split welding manufacturing method and tool for rear force-bearing casing of aero-engine

Abstract

The embodiment of the invention provides a split welding manufacturing method and tool for an aero-engine rear force bearing case, and relates to the field of aero-engine turbine rear force bearing case manufacturing. The invention aims to solve the problems that the large-size turbine rear force-bearing casing is easy to deform and inharmonious and poor in welding quality due to the adoption of a split casting and welding mode. The method comprises the steps that local spot welding positioning is conducted on a plurality of supporting plates and an inner ring in the circumferential direction; the adjacent supporting plates are connected through the multiple pull rod adjusting structures, and the multiple supporting plates are in a loose state; several adjacent supporting plates are welded and fixed, and the lengths of the multiple pull rod adjusting structures are adjusted and locked, so that the multiple remaining supporting plates are tensioned and fixed; and the multiple supporting plates and the inner ring are welded and fixed. The problems of uncoordinated deformation and poor welding seam quality caused by welding deformation in a split welding rear casing scheme are solved, and the machining quality and reliability of a large-size rear casing are improved.

Description

Technical Field

[0001] This invention relates to the field of manufacturing aero-engine turbine rear load-bearing casing, and more specifically, to a method and tooling for manufacturing aero-engine rear load-bearing casing by separate welding. Background Technology

[0002] The turbine rear bearing casing (hereinafter referred to as the "rear casing") of a high-bypass turbofan engine (hereinafter referred to as the "engine") is part of the engine's load-bearing frame. It guides the combustion gases from the low-pressure turbine to the outside of the engine and secures the engine's pivot bearings, transferring rotor loads to the engine mounting section. The rear bearing casing generally includes an outer ring, an inner ring, multiple support plates, and conical walls. High-temperature combustion gases enter the exhaust section through the flow channel formed by the outer and inner rings. The outer and inner rings are connected by multiple support plates. The inner ring is connected to the rear pivot bearing housing, transferring the load from the bearing housing to the support plates, the outer ring, and the entire engine load-bearing system. The support plates between the inner and outer rings are generally hollow, thin-walled, and bladed structures, containing oil pipes and vent pipes. Besides bearing loads, the support plates also insulate the oil and vent pipes from high temperatures.

[0003] The exhaust section load-bearing casing is typically large, with a maximum diameter of around 2 meters. To improve engine efficiency and reduce weight, the load-bearing casing is usually a thin-walled structure. There are generally two methods for manufacturing large, thin-walled load-bearing casings: integral casting and modular casting with welding. Integral casting places high demands on the size of the casting equipment and the maximum casting weight; the larger the size, the lower the yield rate of individual blanks. Modular casting with welding divides the casing structure into multiple castings. The manufacturing difficulty of individual castings is lower, and the yield rate is higher. The blanks are machined and then welded together to form the casing. Therefore, modular casting with welding is generally used for ultra-large rear casings.

[0004] For large-size turbine rear bearing casings, a modular casting and welding process is a feasible and cost-effective manufacturing method. However, the casing's quality and reliability are easily affected by large welding deformations. Taking the support plate and inner ring weld as an example, the central part of the support plate blade has the same wall thickness, but the leading and trailing edges require thicker walls. To ensure argon arc welding penetration, the welding parameters at different positions on the leading and trailing edges differ. Furthermore, since the support plate and inner ring are precision cast, local material inhomogeneity is unavoidable. Under the influence of these factors, unpredictable internal stresses and deformations will occur in the inner ring and support plate during subsequent welding or aging processes. On the one hand, excessive deformation in subsequent welding and machining processes requires reshaping to meet the required precision, and also necessitates the repair and reshaping of other parts to meet subsequent manufacturing needs, affecting production efficiency. On the other hand, the presence of internal stress reduces weld quality, posing a potential threat to the reliability of the engine in service. Summary of the Invention

[0005] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0006] The present invention aims to provide, for example, a method for manufacturing a rear load-bearing casing of an aero-engine by separate welding, which can improve the problems of deformation inconsistency and poor weld quality that are easily generated when using separate casting and welding for large-size turbine rear load-bearing casings.

[0007] The present invention also aims to provide a manufacturing fixture for the separate welding of the rear load-bearing casing of an aero-engine, which can improve the problems of deformation inconsistency and poor weld quality that are easily generated when the large-size turbine rear load-bearing casing is made by separate casting and welding.

[0008] The embodiments of the present invention can be implemented as follows:

[0009] An embodiment of the present invention provides a method for manufacturing a split-welded rear load-bearing casing for an aero-engine. The method includes: positioning multiple support plates by local spot welding along the circumferential direction to the inner ring; connecting adjacent support plates via multiple tie-rod adjustment structures, ensuring the support plates are in a relaxed state; welding and fixing several adjacent support plates, and adjusting and locking the lengths of the tie-rod adjustment structures to tighten and fix the remaining support plates; welding and fixing the multiple support plates to the inner ring; welding the front mounting edge to the front edge of the multiple support plates, and welding the rear mounting edge to the rear edge of the multiple support plates; and removing the tie-rod adjustment structures.

[0010] The length of the tie rod adjustment structure is adjustable. The low-pressure turbine rear bearing casing of the aero-engine includes an inner ring, an outer ring, and multiple support plates. A flow channel is formed between the inner ring and the outer ring. The inner ring and the outer ring are connected by multiple support plates that are circumferentially spaced. The outer ring includes a front mounting edge, a rear mounting edge, and an outer ring sheet metal. The front mounting edge and the rear mounting edge are respectively connected to the front and rear edges of the multiple support plates. The outer ring sheet metal is connected between the front mounting edge and the rear mounting edge and connects to adjacent support plates.

[0011] In addition, the method for manufacturing aero-engine rear load-bearing casing by separate welding provided in the embodiments of the present invention may also have the following additional technical features:

[0012] Optionally, the plurality of support plates include a plurality of lug support plates and a plurality of non-lug support plates, wherein the plurality of lug support plates are arranged adjacent to each other in the circumferential direction and the plurality of non-lug support plates are arranged adjacent to each other in the circumferential direction;

[0013] The step of connecting adjacent support plates through multiple tie rod adjustment structures and slackening the multiple support plates includes: connecting two adjacent non-lifting lug support plates through tie rod adjustment structures, and connecting the two outermost non-lifting lug support plates with the adjacent lifting lug support plates through tie rod adjustment structures, so that the multiple lifting lug support plates and the multiple non-lifting lug support plates are in a slack state;

[0014] The steps of welding and fixing several adjacent support plates, and adjusting and locking the lengths of multiple tie rod adjustment structures to tighten and fix the remaining multiple support plates include: welding and fixing multiple lifting lug support plates, and adjusting and locking the lengths of multiple tie rod adjustment structures to lock and fix multiple non-lifting lug support plates.

[0015] Optionally, the pull rod adjustment structure includes two positioning pull rods and several adjusting shims; one end of the two positioning pull rods is connected by bolts and clamps several adjusting shims, the number of adjusting shims between the two positioning pull rods is adjustable to adjust the length of the pull rod adjustment structure; the ends of the two positioning pull rods away from the adjusting shims are respectively connected to adjacent support plates.

[0016] Optionally, the steps of welding and fixing several adjacent support plates, and adjusting and locking the length of multiple tie rod adjustment structures to tighten and fix the remaining multiple support plates include: welding and fixing several adjacent support plates, adjusting and locking the length of the tie rod adjustment structure by increasing or decreasing the number of adjusting shims in each tie rod adjustment structure by turning the bolts, so as to tighten and fix the remaining multiple support plates.

[0017] Optionally, the steps of welding and fixing several adjacent support plates, adjusting the length of the tie rod adjustment structure by increasing or decreasing the number of adjusting shims in each tie rod adjustment structure by tightening bolts, and locking it to tighten and fix the remaining multiple support plates include: welding and fixing several adjacent support plates, adjusting the length of the tie rod adjustment structure by increasing or decreasing the number of adjusting shims in each tie rod adjustment structure by tightening bolts, adjusting the adjusting shims in groups of two tie rod adjustment structures with opposite circumferential positions, and sequentially adjusting and locking the lengths of multiple groups of circumferential tie rod adjustment structures to tighten and fix the remaining multiple support plates.

[0018] Optionally, two tie rod adjustment structures are connected between two adjacent support plates and are arranged side by side at intervals along the axial direction. The two tie rod adjustment structures between two adjacent support plates form a set.

[0019] The step of adjusting the shims by grouping two circumferentially opposite tie rod adjustment structures into a group, and sequentially adjusting and locking the length of multiple circumferential tie rod adjustment structures includes: adjusting the shims by grouping two circumferentially opposite tie rod adjustment structures into a pair; first adjusting the tie rod adjustment structure located on the front side of the inner ring in one pair of tie rod adjustment structures, then adjusting the tie rod adjustment structure located on the rear side of the inner ring in the other pair of tie rod adjustment structures, and so on, to complete the adjustment of the two pairs of tie rod adjustment structures in a crisscross manner, and sequentially adjusting and locking the length of multiple circumferential tie rod adjustment structures.

[0020] Optionally, the method for manufacturing a split-welded rear load-bearing casing of an aero-engine further includes, after the step of welding and fixing multiple support plates and inner ring, the step of welding the front mounting edge to the front edge of multiple support plates and the step of welding the rear mounting edge to the rear edge of multiple support plates: performing stress-relieving heat treatment on the welded multiple support plates and inner ring.

[0021] Optionally, one end of the support plate connected to the tie rod adjustment structure is provided with a positioning lug, the positioning lug is provided with a bolt hole, and the bolt hole is detachably connected to the positioning tie rod by a bolt;

[0022] The manufacturing method for the split welding of the rear load-bearing casing of the aero-engine also includes the following steps after the step of removing multiple tie rod adjustment structures: cutting off the positioning lugs, welding the outer ring sheet metal between the front mounting edge and the rear mounting edge, and welding it to the adjacent support plate.

[0023] Optionally, the outer ring sheet metal includes two side outer rings and multiple outer ring sheet metals. The two side outer rings are respectively welded to the front mounting edge and the rear mounting edge, and are also welded to the front side edge and the rear side edge of the support plate. The outer ring sheet metal is welded between the two side outer rings and between two adjacent support plates.

[0024] Embodiments of the present invention also provide a manufacturing fixture for the separate welding of the rear load-bearing casing of an aero-engine. This fixture is used to implement a method for manufacturing the separate welding of the rear load-bearing casing of an aero-engine. The fixture includes multiple adjustable rod structures, the length of which is adjustable. These adjustable rod structures are used to detachably connect adjacent support plates and can be removed after the support plates are welded to the inner ring.

[0025] The beneficial effects of the separate welding manufacturing method and tooling for the rear load-bearing casing of an aero-engine according to embodiments of the present invention include, for example:

[0026] The manufacturing method for the split welding of the rear load-bearing casing of an aero-engine includes: positioning multiple support plates by local spot welding along the circumference and the inner ring; connecting adjacent support plates through multiple tie rod adjustment structures, and keeping the multiple support plates in a relaxed state; welding and fixing several adjacent support plates, and adjusting and locking the length of the multiple tie rod adjustment structures to tighten and fix the remaining multiple support plates; welding and fixing multiple support plates to the inner ring; welding the front mounting edge to the front edge of multiple support plates, and welding the rear mounting edge to the rear edge of multiple support plates; and removing the multiple tie rod adjustment structures.

[0027] First, the support plate and inner ring are partially spot-welded for positioning. Then, a tie rod adjustment structure is used for pre-tensioning, which supports and limits the support plate. Next, some adjacent support plates are welded together, and the tie rod adjustment structure is adjusted to tighten and fix the remaining support plates. Finally, the support plates are welded to the inner ring. The adjustable tie rod structure generates a certain pre-tension force on the support plates, and the welding shrinkage deformation is balanced by the pre-tension force. After the pre- and post-welding sides are installed, the tie rod adjustment structure is removed. This improves the problem of deformation inconsistency and poor weld quality caused by welding deformation in the split-welded casing design, and improves the processing quality and reliability of large-size rear casings.

[0028] The tooling for manufacturing a split-welding rear load-bearing casing for aero engines is used to implement the above-mentioned method, which can improve the problems of deformation inconsistency and poor weld quality that are easily caused by the split casting and welding method for large-size turbine rear load-bearing casings. Attached Figure Description

[0029] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0030] Figure 1 A flowchart illustrating the manufacturing method for the split welding of the rear load-bearing casing of an aero-engine provided in an embodiment of the present invention;

[0031] Figure 2 This is a structural schematic diagram of the rear load-bearing casing of an aero-engine provided in an embodiment of the present invention;

[0032] Figure 3 This is a cross-sectional view of the rear load-bearing casing of an aero-engine at the lug support plate, provided in an embodiment of the present invention.

[0033] Figure 4 This is a schematic diagram of the structure of the three lifting lug support plates on the rear load-bearing casing of an aero-engine provided in an embodiment of the present invention;

[0034] Figure 5This is a schematic diagram of the structure of the non-lifting lug support plate of the aero-engine rear load-bearing casing with and without the first positioning lug, provided in an embodiment of the present invention.

[0035] Figure 6 A schematic diagram of the structure of the inner ring of the rear load-bearing casing of an aero-engine provided in an embodiment of the present invention, showing the blade-shaped welding boss.

[0036] Figure 7 A cross-sectional view of the inner ring of the rear load-bearing casing of an aero-engine provided in an embodiment of the present invention, with respect to the blade-shaped welding boss;

[0037] Figure 8 This is a schematic diagram showing the rear load-bearing casing support plate of an aero-engine in a relaxed state after being spot-welded and connected by a tie rod adjustment structure, as provided in an embodiment of the present invention.

[0038] Figure 9 A schematic diagram showing the state of the adjustment structure after welding the rear load-bearing bracket plate of the aero-engine rear bearing casing and adjusting the tie rod, as provided in an embodiment of the present invention.

[0039] Figure 10 This is a schematic diagram of the connection between the tie rod adjustment structure and the non-lifting lug support plate provided in an embodiment of the present invention;

[0040] Figure 11 This is a schematic diagram showing the dimensions of the tie rod adjustment structure connected to the non-lifting lug support plate according to an embodiment of the present invention;

[0041] Figure 12 This is a schematic diagram of the welding of three lifting lug support plates on the rear load-bearing casing of an aero-engine, provided in an embodiment of the present invention.

[0042] Figure 13 A schematic diagram showing the distribution of the tie rod adjustment structure relative to the position of the rear load-bearing casing of an aero-engine provided in an embodiment of the present invention;

[0043] Figure 14 A schematic diagram of a two-rod adjustment structure provided between the support plates according to an embodiment of the present invention;

[0044] Figure 15 This is a cross-sectional view of the lifting lug support plate after welding the pre-installation side and the post-installation side in the split welding manufacturing method of the rear load-bearing casing of an aero-engine provided in an embodiment of the present invention.

[0045] Icons: 1-Inner ring; 11-Leaf-shaped welding boss; 2-Lifting lug support plate; 21-Second positioning lug; 3-Non-lifting lug support plate; 31-First positioning lug; 4-Front mounting edge; 5-Rear mounting edge; 6-Outer ring sheet metal; 7-Side outer ring; 8-Tie rod adjustment structure; 81-Positioning tie rod; 82-Adjusting shim. Detailed Implementation

[0046] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0047] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," "outer," or "vertical" appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use, and does not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0048] At the same time, it should be noted that the terms "first" and "second" are used only for distinguishing descriptions and should not be interpreted as indicating or implying relative importance.

[0049] In the description of this invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components, etc. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0050] The following is combined with Figures 1 to 15 The method for manufacturing a split-welded rear load-bearing casing of an aero-engine provided in this embodiment is described in detail.

[0051] Please refer to Figure 1 , Figure 2 and Figure 3 The present invention provides a method for manufacturing a rear load-bearing casing of an aero-engine by separate welding, the method comprising:

[0052] Step S1: Local spot welding is performed on multiple support plates along the circumferential direction to position them relative to the inner ring 1.

[0053] Step S2: Connect adjacent support plates through multiple tie rod adjustment structures 8 respectively, and make the multiple support plates in a relaxed state;

[0054] Step S3: Weld and fix several adjacent support plates, and adjust and lock the length of multiple tie rod adjustment structures 8 to tighten and fix the remaining multiple support plates.

[0055] Step S4: Weld and fix the multiple support plates to the inner ring 1;

[0056] Step S5: Weld the front mounting edge 4 to the front edge of the multiple support plates, and weld the rear mounting edge 5 to the rear edge of the multiple support plates.

[0057] Step S6: Remove multiple tie rod adjustment structures 8;

[0058] The length of the tie rod adjustment structure 8 is adjustable. The low-pressure turbine rear bearing casing of the aero-engine includes an inner ring 1, an outer ring, and multiple support plates. A flow channel is formed between the inner ring 1 and the outer ring. The inner ring 1 and the outer ring are connected by multiple support plates that are circumferentially spaced. The outer ring includes a front mounting edge 4, a rear mounting edge 5, and an outer ring sheet metal 6. The front mounting edge 4 and the rear mounting edge 5 are respectively connected to the front and rear edges of the multiple support plates. The outer ring sheet metal 6 is connected between the front mounting edge 4 and the rear mounting edge 5 and connects to adjacent support plates.

[0059] It should be noted that "turbofan engine" refers to an aviation gas turbine engine consisting of a fan booster stage, compressor, combustion chamber, high-pressure turbine, low-pressure turbine, and exhaust system. The "turbine rear support casing" in a turbofan engine is located after the low-pressure turbine, guiding the exhaust gas from the low-pressure turbine to the tailpipe and securing the engine's rear pivot bearing. The turbine rear support casing of a high-bypass turbofan engine is hereinafter referred to as the "rear casing."

[0060] After the inner ring 1 forms the internal flow channel of the casing, multiple blade-shaped welding bosses 11 are circumferentially spaced along the upper edge of the inner ring 1, as shown in the reference. Figure 6 Multiple leaf-shaped welding bosses 11 are used to weld with multiple support plates. The inner ring 1 is machined by precision casting and precision milling. The inner ring 1 and the outer ring form the outer flow channel of the rear casing. The front mounting edge 4 and the rear mounting edge 5 of the outer flow channel are machined from forged blanks and the mounting edge features are machined after welding into an integral frame. Multiple outer ring sheet metal 6 are used to fill the outer flow channel wall between the support plates and form the segmented outer ring surface of the outer flow channel.

[0061] First, the support plate is positioned along the outer circumference of the inner ring 1 and the inner ring 1 by local spot welding. Then, the support plates are connected by the tie rod adjustment structure 8. At this time, the tie rod adjustment structure 8 does not tighten the support plates, and the support plates are in a relaxed state with adjustable margin. The tie rod adjustment structure 8 provides support and positioning. Next, several adjacent support plates are welded together. Specifically, the welding between the three lifting lug support plates 2 is completed by electron beam welding. The position between the remaining support plates is further limited. At this time, the tie rod adjustment structure 8 can be adjusted to generate a certain pre-tightening force on the support plates through the adjustable shims 82, tightening and fixing multiple support plates. Then, the support plates are welded to the inner ring 1. The welding shrinkage deformation is balanced by the pre-tightening force, which can improve the problem of deformation inconsistency and poor weld quality caused by welding deformation in the casing scheme after split welding.

[0062] Reference Figure 1 , Figure 2 and Figure 3 In this embodiment, the method for manufacturing a split-welded rear load-bearing casing of an aero-engine further includes step S4, which involves welding and fixing multiple support plates to the inner ring 1, and step S5, which involves welding the front mounting edge 4 to the front edge of multiple support plates and welding the rear mounting edge 5 to the rear edge of multiple support plates. Before this step, stress-relieving heat treatment is performed on the welded multiple support plates and inner ring 1.

[0063] After the tie rod adjustment structure 8 is adjusted, multiple support plates are welded and fixed to the inner ring 1. Specifically, the inner ring 1 and the support plates at position 14 are welded using argon arc welding. Without loosening the tie rod and bolts, the structure undergoes stress-relieving heat treatment. During welding of the support plates to the casing, a certain preload is generated on the support plates through positioning lugs and adjustable shims. The welding shrinkage deformation is balanced by the preload, and stress-relieving heat treatment eliminates welding stress and reduces post-weld deformation.

[0064] Reference Figure 2 , Figure 4 and Figure 5 In this embodiment, the multiple support plates include multiple lug support plates 2 and multiple non-lug support plates 3. The multiple lug support plates 2 are arranged adjacent to each other in the circumferential direction, and the multiple non-lug support plates 3 are arranged adjacent to each other in the circumferential direction. The positioning lugs include a first positioning lug 31 disposed on the non-lug support plate 3 and a second positioning lug 21 disposed on the lug support plate 2.

[0065] Step S2, which connects adjacent support plates through multiple tie rod adjustment structures 8 and puts the multiple support plates in a relaxed state, includes: Step S21, where two adjacent non-lug support plates 3 are connected through tie rod adjustment structures 8, and the two outermost non-lug support plates 3 are connected to adjacent lug support plates 2 through tie rod adjustment structures 8, so that the multiple lug support plates 2 and the multiple non-lug support plates 3 are in a relaxed state;

[0066] Step S3, which involves welding and fixing several adjacent support plates and adjusting and locking the lengths of multiple tie rod adjustment structures 8 to tighten and fix the remaining multiple support plates, includes: Step S31, welding and fixing multiple lug support plates 2 and adjusting and locking the lengths of multiple tie rod adjustment structures 8 to lock and fix multiple non-lug support plates 3.

[0067] The lifting lug support plate 2 is T-shaped and hollow. The T-shaped support plate is precision-cast and then milled to remove excess material before being used for casing welding. The casting of lifting lug support plate 2 has a second positioning lug 21 for positioning on the excess material of the outer flow channel wall. After welding the frame, it is machined to form the required contour. The non-lifting lug support plate 3 is also T-shaped and hollow, with a mounting seat for pipe passage on the outer flow channel. Similar to lifting lug support plate 2, the non-lifting lug support plate 3 is precision-cast and then milled to remove excess material before being used for casing welding. The casting of non-lifting lug support plate 3 has a first positioning lug 31 for positioning on the excess material of the outer flow channel wall. After welding the frame, it is machined to form the required contour.

[0068] The inner ring 1 has multiple non-lug support plates 3 and multiple lug support plates 2. The multiple lug support plates 2 are not connected by a tie rod adjustment structure 8. The non-lug support plates 3 are connected by a tie rod adjustment structure 8. The non-lug support plates 3 and the lug support plates 2 are connected by a tie rod adjustment structure 8.

[0069] After completing the connection of the tie rod adjustment structure 8, first weld and fix multiple lug support plates 2, and then further adjust the tie rod adjustment structure 8 to complete the tightening and fixing of the non-lug support plate 3.

[0070] Reference Figure 8 , Figure 9 and Figure 10 In this embodiment, the pull rod adjustment structure 8 includes two positioning pull rods 81 and several adjusting shims 82; one end of the two positioning pull rods 81 is connected by bolts and clamps several adjusting shims 82, and the number of adjusting shims 82 between the two positioning pull rods 81 is adjustable to adjust the length of the pull rod adjustment structure; the ends of the two positioning pull rods 81 away from the adjusting shims 82 are respectively connected to adjacent support plates.

[0071] The tie rod adjustment structure 8 includes two positioning tie rods 81 and multiple adjusting shims 82. The two positioning tie rods 81 are detachably connected by bolts and nuts. The adjusting shims 82 have multiple thicknesses, generally including 0.2mm, 0.5mm, 1mm, 3mm, etc., without limitation. The combination of adjusting shims 82 of different thicknesses is used to fill the gap between the two tie rods and adjust the preload.

[0072] Reference Figure 11 The positioning tie rod 81 has two length specifications. The first specification's length L0 is calculated by subtracting Δt from half the bolt hole spacing L1 of the second positioning lugs 21 of the two non-lifting lug support plates 3. Δt is the circumferential deformation amount when a single support plate is welded to the inner ring 1, given empirically or obtained through welding tests. (See...) Figure 9 As shown. The length of the second specification of positioning tie rod 81 is half of the distance L2 between the positioning lug holes of the lug support plate 2 and the non-lug support plate 3 minus △t.

[0073] Specifically, the ends of the two positioning rods 81 away from the adjusting shims 82 are respectively provided with fixing holes. Between adjacent non-lifting lug support plates 3 and non-lifting lug support plates 3, the fixing holes of the two positioning rods 81 are respectively connected and fixed to the bolt holes of the first positioning lug 31; between adjacent lifting lug support plates 2 and non-lifting lug support plates 3, the fixing holes of the two positioning rods 81 are respectively bolted to the bolt holes on the second positioning lug 21 and the bolt holes on the first positioning lug 31.

[0074] Reference Figure 8 , Figure 9 and Figure 10 In this embodiment, step S3, which involves welding and fixing several adjacent support plates, and adjusting and locking the lengths of multiple tie rod adjustment structures 8 to tighten and fix the remaining multiple support plates, includes:

[0075] Step S31: Weld and fix several adjacent support plates. Adjust and lock the length of the tie rod adjustment structure 8 by increasing or decreasing the number of adjusting shims 82 in each tie rod adjustment structure 8 by tightening the bolts, so as to tighten and fix the remaining multiple support plates.

[0076] The length of the tie rod adjustment structure 8 is adjusted by increasing or decreasing the number of adjusting shims 82. The adjusting shims 82 have different specifications, such as 0.2mm, 0.5mm, 1mm, 3mm, etc. Initially, the tie rod adjustment structure 8 only pre-tightens the connection between the support plates. After welding between the lug support plates 2, the tie rod adjustment structure 8 is further adjusted and tightened to further correct and tighten the position between the non-lug support plates 3.

[0077] Reference Figure 13 In this embodiment, step S31, which involves welding and fixing several adjacent support plates, adjusting the length of the pull rod adjusting structure 8 by increasing or decreasing the number of adjusting shims 82 in each pull rod adjusting structure 8 by tightening the bolts, and then locking it to tighten and fix the remaining multiple support plates, includes the following steps:

[0078] Step S311: Weld and fix several adjacent support plates. Adjust the length of the pull rod adjustment structure 8 by increasing or decreasing the number of adjusting shims 82 in each pull rod adjustment structure 8 by tightening the bolts. Adjust the adjusting shims 82 in groups of two pull rod adjustment structures 8 that are circumferentially opposite each other. Complete the length adjustment of multiple groups of pull rod adjustment structures 8 in sequence and lock them to tighten and fix the remaining support plates.

[0079] During the adjustment of the tie rod adjustment structure 8, the two tie rod adjustment structures 8 set diagonally can be adjusted sequentially before adjusting the next set of two diagonally distributed tie rod adjustment structures 8. This circumferentially spaced and crisscrossing adjustment ensures the stability of the entire casing and prevents imbalance. It should be noted that "circumferentially opposite positions" and "diagonally distributed" tie rod adjustment structures 8 refer to two tie rod adjustment structures 8 located at circumferential intervals greater than 90° and less than or equal to 180°. For example... Figure 12 In the diagram, positions a and b are two tie rod adjustment structures 8 arranged in opposite directions.

[0080] Reference Figure 13 and Figure 14 In this embodiment, two tie rod adjustment structures 8 are connected between two adjacent support plates and are arranged side by side at intervals along the axial direction. The two tie rod adjustment structures 8 between two adjacent support plates form a group.

[0081] The steps of adjusting the shims 82 by adjusting two circumferentially opposite tie rod adjustment structures 8 as a group, and sequentially completing the length adjustment and locking of multiple circumferential tie rod adjustment structures 8 include:

[0082] Adjusting the shims 82 by taking two sets of circumferentially opposite tie rod adjustment structures 8 as a pair. First, adjust the tie rod adjustment structure 8 located in front of the inner ring 1 in one set of tie rod adjustment structures 8, and then adjust the tie rod adjustment structure 8 located in rear of the inner ring 1 in the other set of tie rod adjustment structures 8. The adjustment of the two sets of tie rod adjustment structures 8 is completed in a cross manner. The length adjustment of the multiple sets of circumferential tie rod adjustment structures 8 is completed and locked in sequence.

[0083] Reference Figure 14 It is from Figure 13 A schematic diagram taken from the side, from Figure 13 Viewed from the side, there are two tie rod adjustment structures 8 distributed along the axial direction. During the adjustment and correction of the tie rod adjustment structures 8, the following adjustments can be made first: Figure 13 At point a Figure 14 The left-hand lever adjustment mechanism 8 is shown in the diagram; adjust it again. Figure 13 At point b Figure 14 The diagram shows the lever adjustment mechanism 8 on the right side, then adjust... Figure 13 At point a Figure 14 The lever adjustment mechanism 8 on the right side is shown in the diagram; final adjustment is required. Figure 13 At point b Figure 14 The left-hand tie rod adjustment structure 8 is shown in the diagram. This completes the adjustment of the two sets of tie rod adjustment structures 8 positioned opposite each other. The remaining circumferentially arranged multiple sets of tie rod adjustment structures 8 are adjusted in the same manner to ensure the stability of the entire frame.

[0084] Reference Figure 2 and Figure 9 In this embodiment, one end of the support plate connecting rod adjustment structure 8 is provided with a positioning lug, the positioning lug is provided with a bolt hole, and the bolt hole is detachably connected to the positioning rod 81 by bolts;

[0085] The manufacturing method of the rear load-bearing casing of an aero-engine also includes the following steps after removing multiple tie rod adjustment structures: cutting off the positioning lugs, welding the outer ring sheet metal 6 between the front mounting edge 4 and the rear mounting edge 5, and welding it to the adjacent support plate.

[0086] Reference Figure 9 After completing the welding of the front mounting edge 4 and the rear mounting edge 5, remove the tie rod adjustment structure 8, and cut off the first positioning lug 31 of the non-lifting lug support plate 3 and the second positioning lug 21 of the lifting lug support plate 2, referring to... Figure 1 Then install the outer ring sheet metal 6.

[0087] Reference Figure 2 In this embodiment, the outer ring sheet metal 6 includes two side outer rings 7 and multiple outer ring sheet metal 6. The two side outer rings 7 are respectively welded to the front mounting edge 4 and the rear mounting edge 5, and are also welded to the front side edge and the rear side edge of the support plate. The outer ring sheet metal 6 is welded between the two side outer rings 7 and between two adjacent support plates.

[0088] by Figure 2 The relative positions of the components are described below. The front mounting edge 4 and the rear mounting edge 5 are welded to the left and right sides of the support plate, respectively. The two outer rings 7 are welded to the inner sides of the front mounting edge 4 and the rear mounting edge 5, respectively. The outer ring sheet metal 6 is welded between the two outer rings. The outer ring sheet metal 6 is welded between the two support plates to form an outer ring structure.

[0089] Embodiments of the present invention also provide a manufacturing fixture for the separate welding of aero-engine rear load-bearing casings. This fixture is used to implement a method for manufacturing aero-engine rear load-bearing casings by separate welding. The fixture includes multiple adjustable rod structures 8, each with an adjustable length. These structures are used to detachably connect adjacent support plates and can be removed after the support plates are welded to the inner ring 1. This method can improve upon the problems of inconsistent deformation and poor weld quality that easily occur when using a separate casting and welding method for large-size turbine rear load-bearing casings.

[0090] According to the method for manufacturing a split-welded rear load-bearing casing of an aero-engine provided in this embodiment, the working principle of the method includes:

[0091] Reference Figure 5The blade-shaped positions of the 11 non-lug support plates 3 are processed. The two ends of the non-lug support plates 3 are provided with first positioning lugs 31 and the bolt holes in the middle of the first positioning lugs 31 are processed.

[0092] Reference Figure 4 The blade shape of the three lifting lug support plates 2 is processed. The lifting lug support plate 2 includes a blade shape and an end face. Among the three lifting lug support plates 2, one end of two of the lifting lug support plates 2 is provided with a second positioning lug 21, and the second positioning lug 21 is provided with a bolt hole. The end face of one of the lifting lug support plates 2 is not provided with a second positioning lug 21, and is located between the other two lifting lug support plates 2.

[0093] Reference Figure 6 and Figure 7 The inner ring 1 is provided with 14 blade-shaped welding bosses 11, and the 14 blade-shaped welding bosses 11 on the inner ring 1 are machined.

[0094] Reference Figure 8 The blade-shaped positions of the 14 support plates are positioned with the blade-shaped welding boss 11 of the inner ring 1 by local spot welding.

[0095] Reference Figure 9 Positioning tie rods 81 and adjusting shims 82 are installed between the 14 support plates, while the front mounting edge 4 and the rear mounting edge 5 are not assembled. The theoretical value of the gap L3 between the positioning tie rods 81 is 2△t. Due to deviations in machining and support plate positioning, the gap between the end faces of the tie rods at different positions is different, requiring the adjusting shims 82 to fill the gaps between the end faces of the tie rods. The shim gap should be less than 0.2mm when the bolts are not tightened with excessive force. All the support plates around the circumference are connected by positioning tie rods 81 and bolts and nuts, and then the nuts are tightened to fix the adjusting shims 82. At this point, the support plates are in a relaxed state, with room for adjustment.

[0096] Reference Figure 12 The welding between the three lug support plates 2 was completed by electron beam welding.

[0097] Reference Figure 13 and Figure 14 Loosen the bolts connecting each positioning tie rod 81 one by one, remove the shims with a thickness of about 0.5-1mm between the end faces, and then tighten the bolts and nuts at that location. Depending on the length of the support plate blade, the amount of shim removal can be increased or decreased to ensure that the support plate and positioning tie rod 81 are taut. Adjust the tie rods in relative positions around the entire circumference one by one to achieve the desired effect. Figure 10For example, first loosen the bolt at point a, remove the adjusting shim 82 in the front tie rod adjusting structure 8, and then tighten it. Next, remove the adjusting shim 82 in the rear tie rod adjusting structure 8 at the circumferentially opposite position b, and then tighten it. Then, successively remove the adjusting shims 82 of the other tie rod adjusting structure 8 at point a and the other tie rod adjusting structure 8 at point b, thus ensuring that the entire frame does not become unstable. After adjusting the adjusting shims 82 between the tie rods in sequence, the entire housing and tooling structure are tightened.

[0098] Reference Figure 12 After adjusting the shims 82 for the entire cycle, the support plates at points 1 and 14 of the inner ring are welded together using argon arc welding. Without loosening the positioning tie rods 81 and bolts, the structure undergoes stress-relieving heat treatment.

[0099] Reference Figure 15 The front mounting edge 4 and the rear mounting edge 5 are welded to the front and rear edges of the support plate by electron beam welding.

[0100] Loosen the connecting bolts of the positioning tie rods 81 between each pair of support plates one by one. Cut off the positioning lugs on the side wall of the support plate, fill the window with the outer side ring 7 and the outer ring sheet metal 6, and spot weld the positioning.

[0101] The outer side ring 7 and outer ring sheet metal 6 in each window are welded by electron beam welding.

[0102] After all welding processes are completed, solution treatment and stress-relieving heat treatment are performed, and non-destructive testing is conducted on the welds.

[0103] After welding is completed, excess material at the front and rear mounting edges 5 and inner ring 1 is removed by machining to meet the installation requirements of the rear casing parts.

[0104] The method for manufacturing a split-welded rear load-bearing casing for an aero-engine provided in this embodiment has at least the following advantages:

[0105] Positioning lugs are added to the sidewalls of the split support plate. When the support plate is welded to the inner ring 1, a certain preload is generated on the support plate through the blade-shaped welding boss 11 and adjustable shims. The welding shrinkage deformation is balanced by the preload, and the welding stress is eliminated by stress-relieving heat treatment, reducing post-weld deformation. This improves the problem of deformation inconsistency and poor weld quality caused by welding deformation in the split welded casing design, and can improve the processing quality and reliability of large-size rear casings.

[0106] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for manufacturing a rear load-bearing casing of an aero-engine by separate welding, characterized in that, The method for manufacturing the rear load-bearing casing of the aero-engine by separate welding includes: Multiple support plates are positioned by local spot welding along the circumferential direction and the inner ring. The adjacent support plates are connected by multiple tie rod adjustment structures, and the multiple support plates are in a relaxed state. Several adjacent support plates are welded and fixed, and the lengths of multiple tie rod adjustment structures are adjusted and locked to tighten and fix the remaining support plates. Multiple support plates are welded and fixed to the inner ring; Weld the front mounting edge to the front edge of multiple support plates, and weld the rear mounting edge to the rear edge of multiple support plates. Remove multiple tie rod adjustment structures; The length of the tie rod adjustment structure is adjustable. The low-pressure turbine rear bearing casing of the aero-engine includes an inner ring, an outer ring, and multiple support plates. A flow channel is formed between the inner ring and the outer ring. The inner ring and the outer ring are connected by multiple support plates that are circumferentially spaced. The outer ring includes a front mounting edge, a rear mounting edge, and an outer ring sheet metal. The front mounting edge and the rear mounting edge are respectively connected to the front and rear edges of the multiple support plates. The outer ring sheet metal is connected between the front mounting edge and the rear mounting edge and connects to adjacent support plates.

2. The method for manufacturing a split-welded rear load-bearing casing of an aero-engine according to claim 1, characterized in that, The plurality of support plates include a plurality of lug support plates and a plurality of non-lug support plates, wherein the plurality of lug support plates are arranged adjacent to each other in the circumferential direction and the plurality of non-lug support plates are arranged adjacent to each other in the circumferential direction; The step of connecting adjacent support plates through multiple tie rod adjustment structures and slackening the multiple support plates includes: The two adjacent non-lifting lug support plates are connected by a tie rod adjustment structure, and the two outermost non-lifting lug support plates are connected to the adjacent lifting lug support plates by a tie rod adjustment structure, so that the multiple lifting lug support plates and the multiple non-lifting lug support plates are in a relaxed state; The steps of welding and fixing several adjacent support plates, and adjusting and locking the lengths of multiple tie rod adjustment structures to tighten and fix the remaining multiple support plates include: Multiple lifting lug support plates are welded and fixed, and the lengths of multiple tie rod adjustment structures are adjusted and locked to lock and fix multiple non-lifting lug support plates.

3. The method for manufacturing a split-welded rear load-bearing casing of an aero-engine according to claim 1, characterized in that, The pull rod adjustment structure includes two positioning pull rods and several adjusting shims; one end of the two positioning pull rods is connected by bolts and clamps several adjusting shims, and the number of adjusting shims between the two positioning pull rods is adjustable to adjust the length of the pull rod adjustment structure; the ends of the two positioning pull rods away from the adjusting shims are respectively connected to adjacent support plates.

4. The method for manufacturing a split-welded rear load-bearing casing of an aero-engine according to claim 3, characterized in that, The steps of welding and fixing several adjacent support plates, and adjusting and locking the lengths of multiple tie rod adjustment structures to tighten and fix the remaining multiple support plates include: Several adjacent support plates are welded and fixed. The length of the tie rod adjustment structure is adjusted and locked by increasing or decreasing the number of adjusting shims in each tie rod adjustment structure by turning the bolts, so as to tighten and fix the remaining multiple support plates.

5. The method for manufacturing a split-welded rear load-bearing casing of an aero-engine according to claim 4, characterized in that, The steps of welding and fixing several adjacent support plates, adjusting the length of the tie rod adjustment structure by increasing or decreasing the number of adjusting shims in each tie rod adjustment structure by tightening bolts, and locking the remaining multiple support plates to tighten and fix them include: Several adjacent support plates are welded and fixed. The length of the tie rod adjustment structure is adjusted by increasing or decreasing the number of adjusting shims in each tie rod adjustment structure by tightening the bolts. The adjusting shims are adjusted in groups of two tie rod adjustment structures that are circumferentially opposite each other. The length adjustment of multiple groups of tie rod adjustment structures in the circumferential direction is completed in sequence and then locked to tighten and fix the remaining support plates.

6. The method for manufacturing a split-welded rear load-bearing casing of an aero-engine according to claim 5, characterized in that, Two tie rod adjustment structures are connected between two adjacent support plates and are arranged side by side at intervals along the axial direction. The two tie rod adjustment structures between two adjacent support plates form a set. The steps of adjusting the shims by adjusting two circumferentially opposite tie rod adjustment structures as a group, and sequentially adjusting and locking the lengths of multiple circumferential tie rod adjustment structures include: Adjust the shims by adjusting two sets of tie rod adjustment structures that are circumferentially opposite each other. First, adjust the tie rod adjustment structure located on the front side of the inner ring in one set of tie rod adjustment structures, and then adjust the tie rod adjustment structure located on the rear side of the inner ring in the other set of tie rod adjustment structures. Repeat this process to adjust the length of the tie rod adjustment structures in multiple sets of circumferential tie rod adjustment structures and lock them in place.

7. The method for manufacturing a split-welded rear load-bearing casing of an aero-engine according to claim 1, characterized in that, The method for manufacturing a split-welded rear load-bearing casing of an aero-engine further includes the steps following the welding and fixing steps of multiple support plates and inner ring, and the steps before welding the front mounting edge to the front edge of the multiple support plates and welding the rear mounting edge to the rear edge of the multiple support plates: Stress-relieving heat treatment was performed on the multiple support plates and inner rings after welding.

8. The method for manufacturing a split-welded rear load-bearing casing of an aero-engine according to claim 3, characterized in that, The support plate is connected to the tie rod adjustment structure at one end, and a positioning lug is provided at the positioning lug. The positioning lug is provided with a bolt hole, and the bolt hole is detachably connected to the positioning tie rod by a bolt. The method for manufacturing a split-welded rear load-bearing casing of an aero-engine also includes steps following the step of removing the multiple tie rod adjustment structures: The positioning lug is cut off, and the outer ring sheet metal is welded between the front mounting edge and the rear mounting edge, and also welded to the adjacent support plate.

9. The method for manufacturing a split-welded rear load-bearing casing of an aero-engine according to claim 8, characterized in that, The outer ring sheet metal includes two side outer rings and multiple outer ring sheet metals. The two side outer rings are respectively welded to the front mounting edge and the rear mounting edge, and are also welded to the front side edge and the rear side edge of the support plate. The outer ring sheet metal is welded between the two side outer rings and between two adjacent support plates.

10. A manufacturing fixture for welding the rear load-bearing casing of an aero-engine, the manufacturing fixture for welding the rear load-bearing casing of an aero-engine as described in any one of claims 1-9, characterized in that, The manufacturing fixture for the separate welding of the rear load-bearing casing of the aero-engine includes multiple tie rod adjustment structures. The length of each tie rod adjustment structure is adjustable. Each tie rod adjustment structure is used to detachably connect adjacent support plates and can be removed after the support plates are welded to the inner ring.

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