A method of manufacturing a cyclone

Abstract

The application discloses a manufacturing method of a cyclone, which comprises the following steps: machining upper and lower wall parts through rough turning, first heat treatment, semi-precision turning, second heat treatment and precision turning in sequence, milling a boss of the lower wall part, milling a cyclone groove of the upper wall part, laser marking a wire hole of the upper and lower wall parts, cutting the cyclone groove of the upper and lower wall parts, and completing the machining of the upper and lower wall parts; removing the oxide skin on the surface of a cyclone vane blank through turning, milling the blank with the oxide skin removed into a wedge-shaped structure cyclone vane, machining an inlet and exhaust edge arc on the wedge-shaped structure cyclone vane, and completing the machining of the fan-shaped structure cyclone vane; assembling the fan-shaped structure cyclone vane with the lower wall part, performing first vacuum brazing, then assembling the upper wall part with the cyclone vane and the lower wall part, and performing second vacuum brazing, thereby obtaining the cyclone. The method can effectively control the machining deformation of the upper and lower wall parts and the cyclone vane of the cyclone assembly, and improves the one-time welding qualification rate of multiple brazing seams of the cyclone assembly.

Description

Technical Field

[0001] This invention belongs to the field of machining technology and relates to a method for manufacturing a hydrocyclone. Background Technology

[0002] The swirler assembly is a crucial component of the aero-engine combustion chamber. Its primary function is to generate a high-speed rotating jet at the head of the combustor, creating a low-pressure zone to ensure stable combustion chamber operation. One swirler assembly comprises an upper wall component, a lower wall component, and swirler blades, all made of GH4648 annealed steel. The front end of the assembly consists of the upper and lower wall components and 88 swirler blades connected by vacuum brazing; the rear end consists of 44 bosses on the lower wall component connected to the upper wall component by vacuum brazing. Furthermore, the swirler assembly of this invention exhibits high molding precision. The widest swirler groove on the upper and lower wall components is only 0.7 mm, with a tolerance of only 0.04 mm. The swirler blades in the assembly have a wedge-shaped blade profile, with a maximum wall thickness of only 0.7 mm, a surface profile tolerance of only 0.03 mm, and a surface roughness of Ra 1.6 μm.

[0003] Traditionally, hydrocyclone assemblies are formed directly as a single unit using casting. However, this method only meets the technical requirements of swirl blade thickness ≥ 1.5 mm, blade profile tolerance ≥ 0.2 mm, and surface roughness Ra ≥ 3.2 μm after assembly. Therefore, manufacturing this hydrocyclone assembly is challenging. During processing, the thin walls of the upper and lower wall components, typical thin-walled annular easily deformable parts, are prone to deformation. This leads to significant deviations between the swirl channels on the upper and lower wall components and their theoretical design positions. Furthermore, after manual bending, the swirl blades exhibit significant springback deformation, with inconsistent springback deformation across each blade. These issues result in extremely uneven fit clearances between the swirl blades and the upper and lower wall components after assembly via the swirl channels, sometimes even preventing proper assembly. Ultimately, this affects the vacuum brazing performance of the swirl blades and the upper and lower wall components. Meanwhile, during the brazing process of hydrocyclone components, the large number of welding points and high weld density around the perimeter make it difficult to guarantee a high first-pass yield. Although 3D printing technology can be used to directly mold hydrocyclone components as a single unit, the material properties limit the required molding precision for hydrocyclone components made of high-temperature alloys. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a method for manufacturing a hydrocyclone, thereby solving the technical problems in the prior art where the upper and lower wall parts are prone to deformation during the processing of hydrocyclone components, resulting in a large deviation between the swirling grooves on the upper and lower wall parts and the theoretical design position; and the swirling vanes in the component undergo large springback deformation after manual bending and forming, and the amount of springback deformation of each swirling vane is inconsistent.

[0005] This invention is achieved through the following technical solution:

[0006] A method for manufacturing a hydrocyclone includes the following steps:

[0007] S1: The inner and outer circles of the upper and lower wall parts are machined sequentially by rough turning, semi-finish turning and finish turning. The upper and lower wall parts are subjected to the first heat treatment between rough turning and semi-finish turning, and the upper and lower wall parts are subjected to the second heat treatment between semi-finish turning and finish turning. Then, the boss of the lower wall part is milled, the swirl groove of the upper wall part is milled, the wire-passing holes of the upper and lower wall parts are laser-drilled, and the swirl grooves of the upper and lower wall parts are cut to complete the machining of the upper and lower wall parts.

[0008] S2: The oxide scale on the surface of the swirl vane blank is removed by turning. The blank with the oxide scale removed is then milled into a cuboid swirl vane. The cuboid swirl vane is then cut into a wedge-shaped swirl vane. The inlet and outlet arcs are then machined on the wedge-shaped swirl vane. The fan-shaped swirl vane is then machined by deburring and polishing. The elastic modulus of the swirl vane blank material is 200-250 GPa.

[0009] S3: Assemble the fan-shaped swirling vane with the swirling groove of the lower wall part and perform a first vacuum brazing. Then, grind and trim the swirling vane and the boss of the lower wall part after the first vacuum brazing with the swirling groove of the upper wall part. After assembling the swirling groove of the upper wall part with the ground swirling vane and the ground boss of the lower wall part, perform a second vacuum brazing to obtain the swirling device.

[0010] Preferably, in step S1, after rough turning, a machining allowance of no more than 0.5 mm on each side is left on both the upper and lower wall parts; after semi-finish turning, a machining allowance of no more than 0.2 mm on each side is left on both the upper and lower wall parts.

[0011] Preferably, in step S1, the diameter of the wire-threading hole is 0.4 mm; the swirl grooves of the upper and lower wall parts are processed by electrical discharge machining (EDM) with a slow wire EDM process.

[0012] Preferably, in step S1, before precision machining, a rigid positioning ring with a clearance of no more than 0.02 mm that fits with the inner circle of the upper wall part and the lower wall part is inserted into the inner shape of the upper wall part and the lower wall part.

[0013] Preferably, in step S2, when processing the wedge-shaped swirl vane and the fan-shaped swirl vane with an inlet side arc and an exhaust side arc, the slow wire EDM method is used.

[0014] Preferably, in step S3, during the grinding and finishing process, the grinding of the vortex vanes and the bosses of the lower wall parts is carried out on the premise that the single-sided fitting gap with the vortex groove of the upper wall parts is not greater than 0.16mm.

[0015] Preferably, in step S3, after assembling the swirl groove of the upper wall part with the welded swirl vane and the boss of the lower wall part, the single-sided fitting clearance between the swirl vane and the boss of the lower wall part and the swirl groove of the upper wall part is checked and is not greater than 0.16mm.

[0016] Preferably, in step S3, nickel-based brazing filler metal is used in both the first and second vacuum brazing processes.

[0017] Preferably, in step S3, both the first vacuum brazing and the second vacuum brazing process include a preheating stage, a stabilization stage, a brazing stage, and a cooling stage.

[0018] Preferably, the heating time of the preheating stage is 60-70 min, and the holding temperature is 470-530℃; the heating time of the stabilization stage is 30-45 min, and the holding temperature is 920-980℃; the heating time of the brazing stage is 5-10 min, and the holding temperature is 1050-1090℃; the holding time of the preheating stage, the stabilization stage, and the brazing stage is 15-25 min each.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] A method for manufacturing a hydrocyclone involves first machining the inner and outer circles of the upper and lower wall parts sequentially through rough turning, semi-finish turning, and finish turning. A first heat treatment is performed on the upper and lower wall parts between rough turning and semi-finish turning, and a second heat treatment is performed on the upper and lower wall parts between semi-finish turning and finish turning. Then, the boss of the lower wall part is milled, the hydrocyclone groove of the upper wall part is milled, the wire-passing holes of the upper and lower wall parts are laser-drilled, and the hydrocyclone groove of the upper and lower wall parts is cut to complete the machining of the upper and lower wall parts.

[0021] The oxide scale on the surface of the hydrocyclone blank is removed by turning. The oxide scale-removed blank is then milled into a cuboid-shaped hydrocyclone. The cuboid-shaped hydrocyclone is then cut into wedge-shaped hydrocyclone sections. Inlet and outlet arcs are then machined onto the wedge-shaped sections. Deburring and polishing complete the machining of the fan-shaped hydrocyclone section. This method effectively controls the machining deformation of the upper and lower wall parts and the hydrocyclone sections, ensuring smooth pre-welding assembly of the hydrocyclone sections with uniform assembly gaps. This lays a solid foundation for excellent vacuum brazing of the hydrocyclone assembly.

[0022] Finally, the fan-shaped swirling vane is assembled with the swirling groove of the lower wall part and vacuum brazed for the first time. Then, the swirling vane and the boss of the lower wall part after the first vacuum brazing are ground and trimmed with the swirling groove of the upper wall part. After that, the swirling groove of the upper wall part is assembled with the ground swirling vane and the ground boss of the lower wall part and vacuum brazed for the second time to obtain the swirling device.

[0023] The invention describes a method for vacuum brazing different parts of the hydrocyclone assembly in two stages, which facilitates assembly and repair welding during the overall manufacturing process, minimizes processing risks, and improves the first-time welding pass rate of the multiple brazed seams of the hydrocyclone assembly.

[0024] Furthermore, in step S1, after rough turning, both the upper and lower wall parts have a machining allowance of no more than 0.5mm on each side, which can effectively meet the machining requirements of subsequent semi-finish turning and finish turning; after semi-finish turning, both the upper and lower wall parts have a machining allowance of no more than 0.2mm on each side, which can effectively meet the machining requirements of subsequent finish turning.

[0025] Furthermore, the diameter of the wire-threading hole is 0.4mm to ensure that the machining width of the vortex groove does not exceed the tolerance; the vortex grooves of the upper and lower wall parts are machined by electrical discharge machining (EDM) with a slow wire EDM process, which can ensure the machining accuracy is within 0.01 to 0.02mm. This is one of the methods to ensure that the assembly gap between the vortex vane, the lower wall part boss, and the corresponding position of the vortex groove on the upper and lower wall parts is 0.16mm.

[0026] Furthermore, in step S1, before precision machining, a rigid positioning ring with a clearance of no more than 0.02mm between its inner circle and the inner circle of the upper and lower wall parts is inserted into the inner shape of the upper and lower wall parts. This can effectively prevent elliptical deformation from occurring during subsequent precision machining of the parts' outer shape, milling of the boss of the lower wall part, and milling of the swirl groove of the upper wall part.

[0027] Furthermore, in step S2, when machining the wedge-shaped swirl vane and the fan-shaped swirl vane with the inlet and outlet arcs, both are machined using electrical discharge machining (EDM) with slow wire cutting, which can effectively meet the machining accuracy requirements.

[0028] Furthermore, in step S3, during the grinding and finishing process, the single-sided fitting gap is no more than 0.16mm. The grinding vortex vane and the boss of the lower wall part are fitted with the vortex groove of the upper wall part. The setting of this single-sided fitting gap effectively ensures the assembly of the vortex vane with the upper wall part and the lower wall part.

[0029] Furthermore, in step S3, after the swirling groove of the upper wall part is fitted with the welded swirling vane and the boss of the lower wall part, the single-sided fitting gap between the swirling vane and the boss of the lower wall part and the swirling groove of the upper wall part is checked to be no more than 0.16mm, which effectively ensures the smooth assembly of the swirling vane with the upper wall part and the lower wall part.

[0030] Furthermore, in step S3, nickel-based brazing filler metal is used in both the first and second vacuum brazing processes to ensure good wetting effect with the GH4648 material parts, which are also nickel-based, during vacuum brazing.

[0031] Furthermore, in step S3, both the first and second vacuum brazing processes include a preheating stage, a stabilization stage, a brazing stage, and a cooling stage. The preheating stage has a heating time of 60–70 min and a holding temperature of 470–530 °C. The stabilization stage has a heating time of 30–45 min and a holding temperature of 920–980 °C. The brazing stage has a heating time of 5–10 min and a holding temperature of 1050–1090 °C. The holding time for the preheating stage, stabilization stage, and brazing stage is 15–25 min, which ensures that the hydrocyclone assembly is welded successfully. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic flowchart of a method for manufacturing a hydrocyclone according to the present invention;

[0034] Figure 2 This is a schematic diagram of the overall structure of a certain aero-engine swirler assembly in Embodiment 2 of the present invention, wherein (a) is a front sectional view of the swirler assembly; and (b) is a sectional view of the swirler blade.

[0035] Figure 3 This is a schematic diagram of the upper wall component structure in Embodiment 2 of the present invention;

[0036] Figure 4 This is a schematic diagram of the lower wall component structure in Embodiment 2 of the present invention, wherein (a) is a front sectional view of the lower wall component; and (b) is a side view of the lower wall component.

[0037] Figure 5 This is a schematic diagram of the swirl vane processing process in Embodiment 2 of the present invention, wherein (a) is a schematic diagram of processing the swirl vane into a rectangular block shape; (b) is a schematic diagram of processing the swirl vane into a preliminary wedge-shaped block shape; and (c) is a schematic diagram of processing the swirl vane into its final shape structure.

[0038] Among them: 1. Upper wall part, 2. Lower wall part, 3. Swirl vane, 4. Rear end boss of lower wall part, 5. Front swirl groove of upper wall part, 6. Rear swirl groove of upper wall part, 7. Front swirl groove of lower wall part. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0041] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0042] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do 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 the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0043] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0044] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0045] The present invention will now be described in further detail with reference to the accompanying drawings:

[0046] Example 1

[0047] like Figure 1 As shown, this invention discloses a method for manufacturing a hydrocyclone, comprising the following steps:

[0048] S1: The inner and outer circles of the upper and lower wall parts are machined sequentially by rough turning, semi-finish turning and finish turning. The upper and lower wall parts are subjected to the first heat treatment between rough turning and semi-finish turning, and the upper and lower wall parts are subjected to the second heat treatment between semi-finish turning and finish turning. Then, the boss of the lower wall part is milled, the swirl groove of the upper wall part is milled, the wire-passing holes of the upper and lower wall parts are laser-drilled, and the swirl grooves of the upper and lower wall parts are cut to complete the machining of the upper and lower wall parts.

[0049] The upper and lower wall components of the hydrocyclone assembly are thin-walled and weakly rigid, making them prone to deformation during machining. To control this deformation and ensure the accurate, consistent, and non-deviation-prone positioning of the swirling channels on the upper and lower wall components during machining, the machining process for the upper and lower wall components must be divided into three stages: rough turning, semi-finish turning, and finish turning. After rough turning, a machining allowance of no more than 0.5 mm per side must be left for the semi-finish turning surface; after semi-finish turning, a machining allowance of no more than 0.2 mm per side must be left for the finish turning surface. Two heat treatment processes to relieve machining stress are also arranged. The first heat treatment is arranged between rough turning and semi-finish turning, and the second heat treatment is arranged between semi-finish turning and finish turning. The purpose is to allow the parts to fully release their large machining stress and deform during heat treatment, ultimately eliminating the deformation through finish turning.

[0050] In addition, after the inner shapes (reference holes) of the upper and lower wall parts are precision machined, a rigid locating ring with a small clearance fit must be installed in the inner shapes (reference holes) to prevent elliptical deformation during subsequent precision machining of the outer shapes, milling of the bosses on the lower wall parts, and milling of the swirl grooves on the upper wall parts. The installation of this rigid locating ring also ensures accurate, consistent, and non-deviation-prone positioning during laser drilling and wire cutting of the swirl grooves on the upper and lower wall parts. The clearance between the rigid locating ring and the inner circles of the upper and lower wall parts should not exceed 0.02mm.

[0051] In addition, the diameter of the wire-threading hole is 0.4 mm; at the same time, the swirl grooves of the upper and lower wall parts are processed by electrical discharge machining (EDM) slow wire cutting process.

[0052] S2: Turning removes the oxide scale from the surface of the swirl vane blank, milling the oxide scale-removed blank into a cuboid swirl vane, then cutting the cuboid swirl vane into a wedge-shaped swirl vane, then machining the inlet side arc and the exhaust side arc on the wedge-shaped swirl vane, and completing the machining of the fan-shaped swirl vane by deburring and polishing.

[0053] The swirl vanes in the hydrocyclone assembly are made of GH4648, a material with a high elastic modulus, and have a wedge-shaped blade profile. In a preferred embodiment, the elastic modulus of the swirl vane blank material is 200-250 GPa. To avoid large springback deformation of the part surface after the swirl vane is manually bent from sheet metal, and to ensure smooth assembly between the swirl vane and the upper and lower wall parts before vacuum brazing of the hydrocyclone assembly, firstly, a GH4648 bar stock is selected as the blank for machining the swirl vane, and the oxide scale on the surface of the bar stock is removed by turning; the bar stock is milled into multiple rectangular blocks of suitable size; the rectangular blocks of the above-mentioned size are machined into a preliminary wedge-shaped structure of suitable size for the swirl vane using electrical discharge machining (EDM), i.e., wedge blocks; the wedge blocks of the above-mentioned size are machined with inlet side arcs and exhaust side arcs using EDM, so that the swirl vane becomes its final shape structure.

[0054] S3: Assemble the fan-shaped swirling vane with the swirling groove of the lower wall part and perform a first vacuum brazing. Then, grind and trim the swirling vane and the boss of the lower wall part after the first vacuum brazing with the swirling groove of the upper wall part. After assembling the swirling groove of the upper wall part with the ground swirling vane and the ground boss of the lower wall part, perform a second vacuum brazing to obtain the swirling device.

[0055] The hydrocyclone assembly involves vacuum brazing of its multiple swirling vanes to upper and lower wall components, as well as vacuum brazing between the upper and lower wall components. With numerous welding points and a high density of welds around the perimeter, ensuring a high first-pass yield rate is challenging. To ensure the welding quality of the hydrocyclone assembly described in this invention, firstly, before the first vacuum brazing, the lower end of the hydrocyclone vane is fully inserted into the hydrocyclone groove of the lower wall component, and a feeler gauge is used to check and ensure that the single-sided fit clearance between the lower end of the hydrocyclone vane and the hydrocyclone groove of the lower wall component is uniform; the hydrocyclone vane and the lower wall component are then subjected to the first vacuum brazing; after the first vacuum brazing is qualified, the upper end of the hydrocyclone vane and the upper end joint of the boss of the lower wall component are ground and trimmed to ensure that the grinding and trimming parts at these two locations meet the condition of uniform assembly clearance with the hydrocyclone groove of the upper wall component; the upper end of the hydrocyclone vane and the upper end joint of the boss of the lower wall component are installed into the hydrocyclone groove of the upper wall component, and a feeler gauge is used to check and ensure that the single-sided fit clearance between the upper end of the hydrocyclone vane and the upper end joint of the boss of the lower wall component and the hydrocyclone groove of the upper wall component is uniform; the hydrocyclone vane, the lower wall component, and the upper wall component are then subjected to the second vacuum brazing.

[0056] Furthermore, based on the fact that all individual components of the hydrocyclone assembly described in this invention are made of high-temperature alloy GH4648, and the brazing filler metal is B-Ni73CrSiB nickel-based filler metal, this ensures good wetting effect with the nickel-based GH4648 material components during vacuum brazing. Simultaneously, considering the assembly structure characteristics of the brazing parts of this hydrocyclone assembly, a paste-like filler metal is added to the brazing joint of the cyclone vanes, allowing the melted filler metal to flow directly into the weld, effectively connecting the base components. The hydrocyclone assembly is then welded using optimized brazing parameters determined through process testing.

[0057] This invention overcomes the limitation of low precision when directly molding hydrocyclone components as a single unit using casting and 3D printing technology. The processing deformation of the upper and lower wall parts and swirling vanes of the hydrocyclone component is effectively controlled, ensuring smooth pre-welding assembly between the swirling vanes and the upper and lower wall parts, with uniform assembly gaps, thus laying a solid foundation for excellent vacuum brazing of the hydrocyclone component. The invention's method of performing vacuum brazing on different parts in two stages facilitates assembly and repair welding during the overall manufacturing process, minimizing processing risks and improving the first-time welding pass rate of multiple brazed seams in the hydrocyclone component.

[0058] The purpose of this invention is to provide a high-precision manufacturing method for aero-engine cyclone assemblies. Traditional methods use casting to directly form the cyclone assembly as a single piece. However, this method can only meet the technical requirements of cyclone blade thickness ≥ 1.5 mm, blade profile tolerance ≥ 0.2 mm, and surface roughness Ra ≥ 3.2 μm after forming the cyclone assembly. Therefore, it cannot meet the high-precision forming requirements of the cyclone assembly referred to in this invention. Although 3D printing technology can also be used to directly form the cyclone assembly as a single piece, for cyclone assemblies made of high-temperature alloys, the material properties limit its ability to achieve the forming precision required by this invention. Furthermore, in traditional machining, controlling deformation is also a challenge for the weakly rigid, thin-walled upper and lower wall parts of the cyclone assembly.

[0059] Compared to traditional methods, this invention, based on the structural and molding precision requirements of the hydrocyclone assembly, decomposes the manufacturing of the hydrocyclone assembly into a process from parts to the assembly, rather than directly molding it as a single whole. Based on this, this invention optimizes and summarizes a set of methods for controlling the deformation of the upper and lower wall parts in the hydrocyclone assembly, a process for minimizing the deformation of the cyclone vanes, and a method for uniformly controlling the assembly gaps between relevant parts of the hydrocyclone assembly before vacuum brazing. This invention also discloses the brazing process parameters for the hydrocyclone assembly.

[0060] Example 2

[0061] To further illustrate the technical solution of this invention, a high-precision manufacturing method for a certain engine cyclone assembly will be used as an example:

[0062] like Figure 2 As shown, the overall structure of a certain type of engine swirler assembly is as follows: its front end consists of 88 swirling blades 3 placed between the upper wall part 1 and the lower wall part 2, which are connected to the upper and lower wall parts by vacuum brazing; its rear end consists of 44 rear end bosses 4 of the lower wall part, which are connected to the upper wall part 1 by vacuum brazing.

[0063] The following section describes the processing and manufacturing methods of this hydrocyclone assembly, from its parts to its final form, based on its specific structural characteristics.

[0064] 1. Machining process of upper and lower wall parts

[0065] The hydrocyclone assembly of this invention includes an upper wall component 1 and a lower wall component 2, both made of GH4648, a difficult-to-machine high-temperature alloy with a low machinability coefficient. The upper wall component 1 has a diameter of Φ318mm, and the lower wall component 2 has a diameter of Φ298mm. The thinnest wall thickness of both components is only 1.5mm, making them typical thin-walled, easily deformable annular parts. During processing, the upper wall component 1 and the lower wall component 2 are highly susceptible to elliptical deformation. A schematic diagram of the upper wall component 1 is shown below. Figure 3 This deformation will cause the front swirling groove 5 and rear swirling groove 6 of the upper wall part 1, and the front swirling groove 7 of the lower wall part 2 on the wall plate to deviate significantly from their theoretical design positions during processing. This ultimately affects the assembly and vacuum brazing effect between the swirling vanes 3 and the rear boss 4 of the lower wall part in the hydrocyclone assembly and the upper wall part 1 and lower wall part 2 via the front swirling groove 5, rear swirling groove 6, and front swirling groove 7 on the wall plate of the lower wall part 2. Therefore, the deformation control method for the upper wall part 1 and lower wall part 2 in the hydrocyclone assembly referred to in this invention is one of the key technical points of this invention.

[0066] Therefore, based on the above, the overall manufacturing process route for the upper wall part 1 and the lower wall part 2, optimized and summarized by this invention, and the key points of its processing deformation control method are as follows:

[0067] (1) The overall manufacturing process route for the upper and lower wall parts is as follows:

[0068] Rough turning of end face and inner and outer circles — First heat treatment to relieve stress — Semi-finish turning of end face and inner and outer circles — Second heat treatment to relieve stress — Finish turning of inner shape (reference hole) — Finish turning of outer shape — Milling of 44 rear end bosses of lower wall parts 4 — Milling of rear end swirl grooves of upper wall parts 6 — Laser drilling of wire through holes — Front end swirl grooves of upper wall parts 5 and lower wall parts 7 — Deburring.

[0069] (2) The key points of the machining deformation control method for upper and lower wall parts are as follows:

[0070] 1) The machining process of the upper wall part 1 and the lower wall part 2 must be divided into three stages: rough turning, semi-finish turning and finish turning. After rough turning, a machining allowance of no more than 0.5 mm on one side should be left for the semi-finish turning surface; after semi-finish turning, a machining allowance of no more than 0.2 mm on one side should be left for the finish turning surface.

[0071] 2) During the machining process of upper wall part 1 and lower wall part 2, two heat treatment processes to relieve machining stress must be arranged. The first process should be arranged between rough turning and semi-finish turning, and the second process should be arranged between semi-finish turning and finish turning. This allows the upper wall part 1 and lower wall part 2 to fully release their large machining stress after rough turning and semi-finish turning, and to cause deformation in the upper wall part 1 and lower wall part 2. Finally, the deformation is eliminated by finish turning the upper wall part 1 and lower wall part 2.

[0072] 3) On the wall panels of the upper wall component 1 and the lower wall component 2, the swirling grooves 5 and 7 at the front end of the upper wall component, used for assembling the swirling vane 3, are closed grooves. The widest part of these grooves is only 0.7 mm, with a tolerance of 0.04 mm, making them very narrow and highly precise. Therefore, based on the structural characteristics of the swirling grooves 5 and 7 at the front end of the upper wall component 1 and the lower wall component 2 of this hydrocyclone assembly, the processing procedure for the swirling grooves 5 and 7 at the front end of the upper wall component 1 and the lower wall component 2 on the wall panels is as follows: first, a Φ0.4 mm wire-threading hole is drilled using a laser; then, the swirling grooves 5 and 7 at the front end of the upper wall component are processed using an electrical discharge machining (EDM) slow wire cutting process.

[0073] 4) After the inner shapes (reference holes) of the upper wall part 1 and the lower wall part 2 are precision machined, a rigid locating ring with a single-sided clearance of no more than 0.02mm must be installed in the inner shapes (reference holes) to prevent elliptical deformation during subsequent precision machining of the outer shapes of the upper and lower wall parts, milling of the rear end boss 4 of the lower wall part, and the rear end swirl groove 6 of the upper wall part. Simultaneously, the installation of this rigid locating ring ensures the accuracy, consistency, and non-deviation of the positions of the laser-drilled and wire-cut grooves of the front end swirl grooves 5 and 7 of the upper and lower wall parts.

[0074] 2. Processing technology of cyclone vanes

[0075] The swirl vane 3 of the hydrocyclone assembly referred to in this invention is made of GH4648, the same material as the upper and lower wall parts, and has a high elastic modulus (212 GPa). After molding, the swirl vane 3 has a wedge-shaped blade, with a maximum wall thickness of only 0.7 mm, a surface profile tolerance of 0.03 mm, and a surface roughness of Ra 1.6 μm. Due to the very small size of the molded part (see...), Figure 5 (c) Therefore, if a 0.7mm thick sheet is used for cutting and then manually bent during the processing of the swirl vane 3, the surface of the part will experience significant springback deformation. Furthermore, because the springback deformation of each swirl vane 3 is inconsistent, the 0.16mm clearance on one side after assembly with the upper and lower wall parts of the hydrocyclone assembly via the swirl groove is extremely uneven, sometimes even preventing installation. This ultimately affects the vacuum brazing effect between the swirl vane 3 and the upper and lower wall parts of the hydrocyclone assembly. Therefore, the small deformation processing method for the swirl vane 3 in the hydrocyclone assembly referred to in this invention is also a key technical point of this invention.

[0076] Therefore, based on the above, the optimized and summarized small deformation processing method for the swirl vane 3 of this invention is as follows:

[0077] (1) Select GH4648 bar stock as the blank for processing cyclone blade 3;

[0078] (2) Remove the oxide scale from the surface of the bar stock by turning until the color of the metal matrix is ​​completely visible;

[0079] (3) Mill the bar stock into multiple rectangular blocks with dimensions of length × width × height = 18mm × 12mm × 10mm, such as Figure 5 (a);

[0080] (4) Using electrical discharge machining (EDM) wire cutting technology, such as... Figure 5 (a) The rectangular block of the specified dimensions is processed into the preliminary shape structure of the swirl vane 3. That is, the rectangular block with length × width × height = 18mm × 12mm × 10mm is processed into a wedge-shaped block with length × width × height = 14.61mm × 9mm × 10mm, an included angle of 101.52°, an included angle transition arc of R3.8mm, and a thickness of 0.7mm. Figure 5 (b);

[0081] (5) Along Figure 5 (c) From the right view direction of the main view, an electrical discharge machining (EDM) wire cutting process is used to... Figure 4 (b) The wedge-shaped block of the specified dimensions is processed into the final shape structure of the swirl vane 3. Specifically, the wedge-shaped block, with dimensions of length × width × height = 14.61mm × 9mm × 10mm, an included angle of 101.52°, an included angle transition arc of R3.8mm, and a thickness of 0.7mm, is processed into a fan-shaped wedge-shaped block with dimensions of length × width × height = 14.61mm × 9mm × 7.5mm, an included angle of 101.52°, an included angle transition arc of R3.8mm, a thickness of 0.7mm, and an intake side arc of R160 and an exhaust side arc of R152.5. Figure 5 (c)

[0082] (6) Deburring and local polishing of the swirl vane 3 by fitter.

[0083] The deformation of the swirl vane 3 processed by the above process can be controlled within 0.015 to 0.03 mm. This ensures that the 0.16 mm fit gap on one side is uniform after the swirl vane 3 is assembled with the upper and lower wall parts of the hydrocyclone assembly through the swirl groove, and lays the foundation for the excellent vacuum brazing between the swirl vane 3 and the upper and lower wall parts.

[0084] 3. Processing technology of hydrocyclone components

[0085] The hydrocyclone assembly of this invention connects the front ends of its upper and lower wall parts via vacuum brazing using 88 swirling vanes 3; and the rear end of the lower wall part 2 is also vacuum brazed to the rear end of the upper wall part 1 via 44 rear end bosses 4 on its outer circumference. This results in a large number of vacuum brazing points in the hydrocyclone assembly, leading to a high weld density and making it difficult to guarantee a high first-pass yield. Therefore, to ensure the quality of the multiple brazing seams in the hydrocyclone assembly, the method for uniformly controlling the fit clearance between the swirling vanes 3 at the front end of the hydrocyclone assembly and the swirling grooves of the upper and lower wall parts, and between the rear end bosses 4 of the lower wall part and the swirling grooves 6 of the upper wall part 1, as well as the vacuum brazing process parameters used in this hydrocyclone assembly, are key technical points of this invention.

[0086] Therefore, based on the above, the key points of the optimized and summarized overall manufacturing process route for the hydrocyclone assembly and the method for uniformly controlling the fitting clearance of related parts before vacuum brazing are as follows:

[0087] (1) The overall manufacturing process route for the hydrocyclone assembly is as follows:

[0088] Assemble the swirl vane 3 and the lower wall part 2—first vacuum brazing—air tightness test—repair welding—grind the upper end joint of the swirl vane 3 and the rear end boss 4 of the lower wall part—assemble the swirl vane 3 and the rear end boss 4 of the lower wall part onto the upper wall part 1—second vacuum brazing—marking—air flow test.

[0089] (2) Before vacuum brazing, the key points for controlling the uniformity of the mating clearance of related parts are as follows:

[0090] 1) Before the first vacuum brazing, the lower end of the swirl vane 3 is fully inserted into the swirl groove of the lower wall part 2. The lower end of the swirl vane 3 and the swirl groove of the lower wall part 2 are checked and ensured to be evenly distributed within 0.16mm on one side by inserting a feeler gauge.

[0091] 2) Perform the first vacuum brazing of the swirl vane and the lower wall parts;

[0092] 3) After the first vacuum brazing is qualified, the upper end of the swirling plate 3 and the upper end of the rear boss 4 of the lower wall part are fitted with a single-sided fitting gap of no more than 0.16mm.

[0093] 4) Insert the upper end of the swirl vane 3 and the upper end of the rear end boss 4 of the lower wall part into the swirl groove of the upper wall part 1, and use feeler gauges to check and ensure that the single-sided fitting clearance between the upper end of the swirl vane 3 and the upper end of the rear end boss 4 of the lower wall part and the swirl groove of the upper wall part 1 is evenly distributed within 0.16mm.

[0094] 5) Perform a second vacuum brazing of the swirl vane 3, the lower wall part 2, and the upper wall part 1.

[0095] This invention utilizes a method of vacuum brazing different parts of the hydrocyclone assembly in two stages. This facilitates the assembly and repair welding of the hydrocyclone assembly during the overall manufacturing process, minimizes processing risks, and improves the quality of the multiple brazed seams and the first-time welding pass rate of the hydrocyclone assembly.

[0096] Furthermore, given that the materials of each individual component (upper wall component 1, lower wall component 2, and cyclone vane 3) of the hydrocyclone assembly referred to in this invention are all high-temperature alloy GH4648, B-Ni73CrSiB nickel-based brazing filler metal is selected during assembly brazing to ensure that the filler metal has a good wetting effect with the components made of the same nickel-based GH4648 material during vacuum brazing. Simultaneously, based on the assembly structure characteristics of the brazing parts of the hydrocyclone assembly, a paste-like brazing filler metal is added to the brazing joint of the cyclone vane, allowing the melted filler metal to flow directly into the weld, effectively connecting the base components and avoiding welding defects such as incomplete welding and voids. The vacuum brazing process parameters and objectives for relevant parts of the hydrocyclone assembly referred to in this invention are shown in Table 1:

[0097]

[0098] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for manufacturing a hydrocyclone, characterized in that, Includes the following steps: S1: The inner and outer circles of the upper and lower wall parts are machined sequentially by rough turning, semi-finish turning, and finish turning. A first heat treatment is performed on the upper and lower wall parts between rough turning and semi-finish turning, and a second heat treatment is performed on the upper and lower wall parts between semi-finish turning and finish turning. Then, the boss of the lower wall part is milled, the swirl groove of the upper wall part is milled, the wire-passing holes of the upper and lower wall parts are laser-drilled, and the swirl grooves of the upper and lower wall parts are cut to complete the machining of the upper and lower wall parts. The thinnest wall thickness of the upper and lower wall parts is 1.5mm. Before precision machining, a rigid positioning ring with a clearance of no more than 0.02 mm that fits with the inner circle of the upper and lower wall parts is inserted into the inner shape of the upper and lower wall parts. After rough turning, a machining allowance of no more than 0.5 mm is left on each side of the upper and lower wall parts; after semi-finish turning, a machining allowance of no more than 0.2 mm is left on each side of the upper and lower wall parts. The diameter of the wire-threading hole is 0.4 mm; the swirl grooves of the upper and lower wall parts are processed by electrical discharge machining (EDM) with a slow wire EDM process. S2: The oxide scale on the surface of the swirl vane blank is removed by turning. The blank with the oxide scale removed is then milled into a cuboid-shaped swirl vane. The cuboid-shaped swirl vane is then cut into a wedge-shaped swirl vane. The inlet and outlet arcs are then machined on the wedge-shaped swirl vane. The fan-shaped swirl vane is then machined by deburring and polishing. The elastic modulus of the swirl vane blank material is 200~250GPa. The swirl vane blank material is GH4648. When machining wedge-shaped swirl vanes and fan-shaped swirl vanes with inlet and outlet arcs, slow wire EDM is used. S3: Assemble the fan-shaped swirling vane with the swirling groove of the lower wall part and perform a first vacuum brazing. Then, grind and trim the swirling vane and the boss of the lower wall part after the first vacuum brazing with the swirling groove of the upper wall part. Then, assemble the swirling groove of the upper wall part with the ground swirling vane and the ground boss of the lower wall part and perform a second vacuum brazing to obtain the swirling device. During the grinding and finishing process, the grinding of the vortex vanes and the bosses of the lower wall parts is carried out under the premise that the single-sided fitting gap with the vortex groove of the upper wall parts is no more than 0.16mm. After assembling the swirl groove of the upper wall part with the welded swirl vane and the boss of the lower wall part, check that the single-sided fitting clearance between the swirl vane and the boss of the lower wall part and the swirl groove of the upper wall part is no greater than 0.16mm. Nickel-based brazing filler metal was used in both the first and second vacuum brazing processes. Both the first and second vacuum brazing processes include a preheating stage, a stabilization stage, a brazing stage, and a cooling stage. The preheating stage has a heating time of 60-70 minutes and a holding temperature of 470-530°C; the stabilization stage has a heating time of 30-45 minutes and a holding temperature of 920-980°C; the brazing stage has a heating time of 5-10 minutes and a holding temperature of 1050-1090°C; and the holding time for the preheating, stabilization, and brazing stages is 15-25 minutes each.

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