A machining fixture and machining method for the mating surface of an embedded horizontal flange split casing.

Abstract

This invention discloses a machining fixture and method for machining the mating surface of an embedded horizontal flange split casing, belonging to the field of machining technology. The fixture includes a second adapter seat, a first adapter seat, and a base connected sequentially from top to bottom. The base, the second adapter seat, and the first adapter seat are all semi-annular structures, and the radii of the second adapter seat and the first adapter seat are the same as the top radius of the base. Several pressure plates for fixing the casing to be machined are provided on the second adapter seat, the first adapter seat, and the base, with the pressure plates positioned near the mating surface of the casing. This invention solves the problems of large deformation and high machining difficulty of the mating surface of large casings, addresses the issues of vibration and difficulty in ensuring accuracy using conventional methods, improves the pass rate of colorimetric inspection of mating surfaces of high-pressure casings and other parts, achieves stable machining of the casing mating surface, and meets the machining requirements of the parts.

Description

Technical Field

[0001] This invention belongs to the field of machining technology and relates to a machining fixture and machining method for the split surface of an embedded horizontal flange split casing. Background Technology

[0002] In the design of large gas turbines, the compressor casing is typically designed as an embedded horizontal flange split structure. This type of split casing presents technical challenges, including decreased rigidity after splitting, significant warpage, large casing ellipticity, and poor consistency between the two halves. The machining quality of the splitting surface is particularly crucial. The machining accuracy of the splitting surface directly affects the assembly quality of the two halves. If the splitting surface is uneven, gaps will appear during assembly, leading to loose assembly and affecting the overall strength and stability of the casing. Furthermore, the quality of the splitting surface is closely related to sealing performance. During gas turbine operation, the casing needs to maintain a certain pressure and gas environment. Poor sealing of the splitting surface can lead to gas leakage, reducing gas turbine efficiency and potentially causing safety accidents. Therefore, the design of the casing places high demands on the roughness, flatness, and colorimetric inspection of the splitting surface.

[0003] The low-pressure casing of a certain type of gas turbine ( Figure 3 (As shown) is a split casing with an embedded horizontal flange welded structure. The low-pressure casing has a long horizontal split surface, and the mating surface has strict requirements for colorimetric inspection and surface roughness. In the actual manufacturing process, due to the excessive height of the parts, when milling the mating surface with an end mill, a large vibration occurs at the upper end of the parts as soon as the cutter contacts the parts, resulting in vibration marks on the mating surface, making it impossible to guarantee the surface roughness. Secondly, the maximum machining allowance per cut cannot be too large, leading to low machining efficiency. Thirdly, the relatively long horizontal split surface of the casing is prone to clamping and machining deformation, and the mating surfaces on both sides of the machined half of the casing are prone to twisting, causing the two mating surfaces to not be in the same plane. If the two mating surfaces are not machined evenly, it is difficult to guarantee the requirements for colorimetric inspection.

[0004] In summary, while some traditional machining methods and techniques exist for processing the split surfaces of large gas turbine casings, these methods have significant limitations in addressing the aforementioned problems. Therefore, there is an urgent need to master a highly efficient and precise machining technique for the split surfaces of large gas turbine casings to directly ensure the machining quality of the horizontal split surfaces. Summary of the Invention

[0005] The purpose of this invention is to provide a machining fixture and machining method for the split surface of an embedded horizontal flange split casing, so as to solve the technical problem that the machining method of the split casing split surface in the prior art is difficult to effectively control the vibration of the parts during the machining process, which affects the machining quality and machining efficiency.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] In a first aspect, the present invention provides a machining fixture for the split surface of an embedded horizontal flange split housing, comprising a second adapter seat, a first adapter seat, and a base connected sequentially from top to bottom; the base, the second adapter seat, and the first adapter seat are all semi-annular structures, and the radii of the second adapter seat and the first adapter seat are the same as the top radius of the base; the second adapter seat, the first adapter seat, and the base are each provided with a plurality of pressure plates for fixing the housing to be machined, and the pressure plates are located near the split surface of the housing to be machined.

[0008] Furthermore, the substrate is a semi-annular stepped structure with an upper diameter smaller than a lower diameter, and has a positioning stop for positioning the inner circle of the casing to be processed.

[0009] Furthermore, the pressure plate includes a first pressure plate, a second pressure plate, and a third pressure plate; the first pressure plate is located on both sides of the second adapter seat and the lower part of the first adapter seat, and is used to press the inner annular groove of the machine housing to be processed; the second pressure plate is located on both sides of the top of the second adapter seat, and is used to press the upper mounting edge of the machine housing to be processed; the third pressure plate is located on both sides of the middle step of the base, and is used to press the lower mounting edge of the machine housing to be processed.

[0010] Furthermore, the first pressure plate is connected to the second adapter or the first adapter via a second connector, and a compression spring and a second washer are also provided between the second connector and the second adapter or the first adapter.

[0011] Furthermore, the second pressure plate is a movable wide-head pressure plate, and the second pressure plate is connected to the top of the second adapter seat through a third connector; the first adapter seat is fixed to the base through a first connector; the second adapter seat is fixed to the first adapter seat through a first connector, and a first washer is provided between the first connector and the first adapter seat or the second adapter seat; several fourth connectors are also installed on the step in the middle of the base.

[0012] Furthermore, the third connector includes an adjusting bolt located at one end of the second pressure plate and a bolt located in the middle of the second pressure plate. The bolt is connected to the top of the second adapter via a shouldered hexagonal nut and a screw-in threaded bushing.

[0013] Secondly, the present invention provides a method for machining the mating surface of an embedded horizontal flange split housing, based on the above-mentioned machining fixture for the mating surface of an embedded horizontal flange split housing, comprising the following steps:

[0014] The housing part to be processed is clamped on the fixture, and the runout of the mating surface is detected by dial indicator along the axial direction of the housing. Areas with runout values ​​greater than the preset threshold are welded.

[0015] Use a feeler gauge to check and ensure that the housing parts to be processed are clamped on the fixture;

[0016] The mating surfaces of the casing to be machined are successively rough-bored and finish-bored;

[0017] The machined casing is removed from the fixture, and the mating surfaces of the casing are scraped to complete the machining process.

[0018] Furthermore, the preset threshold for the fluctuation value is 0.05.

[0019] Furthermore, the rough boring has a cutting speed of 85 mm / min to 100 mm / min, a feed rate of 100 mm / min to 120 mm / min, and a depth of cut of not less than 2 / 3 of the tool tip radius; the finish boring has a cutting speed of 75 mm / min to 95 mm / min, a feed rate of 100 mm / min to 120 mm / min, and a depth of cut of not less than 1 / 3 of the tool tip radius; the time interval between rough boring and finish boring does not exceed 1 hour.

[0020] Furthermore, the step of removing the processed casing from the fixture and scraping the casing's mating surfaces to complete the processing also includes: performing a color check and a feeler gauge check on the scraped casing's mating surfaces. If the color check or feeler gauge check fails, the casing's mating surfaces are scraped again.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention discloses a machining fixture for the mating surface of an embedded horizontal flange split housing, comprising a second adapter seat, a first adapter seat, and a base connected sequentially from top to bottom. This layered internal clamping structure applies force to the housing's internal shape from different levels, increasing the rigid clamping force. Furthermore, several pressure plates are provided on the second adapter seat, the first adapter seat, and the base to clamp the housing to be processed, clamping the part from different directions and positions, effectively reducing vibration caused by excessive part height during processing, avoiding the generation of vibration marks, and ensuring the surface roughness of the mating surface. This fixture provides a stable and precise machining environment, making tool cutting smoother and improving machining efficiency. Simultaneously, precise clamping and positioning ensure the accuracy of machining dimensions, eliminate vibration phenomena, achieve good surface roughness and perpendicularity, improve the pass rate of color inspection of the mating surface, and reduce the subsequent grinding workload.

[0023] This invention also discloses a machining method for the mating surface of an embedded horizontal flange split casing. After clamping the casing part to be machined onto a fixture, the runout of the mating surface is detected along the casing axis using a dial indicator, which can accurately identify uneven areas on the mating surface. Areas with runout values ​​exceeding a preset threshold are then welded over, effectively correcting initial defects on the mating surface and providing a good foundation for subsequent machining. Then, a feeler gauge is used to ensure the casing part is firmly clamped on the fixture, guaranteeing a stable and secure clamping state during machining. This reduces vibration and displacement caused by loosening of the part during machining, avoiding problems such as vibration marks on the machined surface, further improving the surface roughness and precision, and ensuring the stability of machining quality. This invention performs rough boring and fine boring sequentially on the mating surface of the casing, changing the conventional milling method for flat surfaces. Rough boring can quickly remove most of the excess material and improve machining efficiency; fine boring can ensure the final machining accuracy of the mating surfaces, so that the surface roughness can directly reach a high level, and can be applied to the machining of the mating surfaces of various types of split casings. Attached Figure Description

[0024] 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.

[0025] Figure 1 This is a schematic diagram of a machining fixture structure for the split surface of an embedded horizontal flange split housing according to the present invention;

[0026] Figure 2 This is a schematic diagram of the mounting of the half-casing and the fixture according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the half-casing structure according to an embodiment of the present invention;

[0028] Figure 4 for Figure 3 Sectional view of section AA;

[0029] Figure 5 for Figure 3 View from direction A and schematic diagram of the weld overlay area.

[0030] Wherein: 1-Base; 2-First pressure plate; 3-First adapter; 4-Second adapter; 5-Second pressure plate; 6-Third pressure plate; 7-First connector; 8-Second connector; 9-Third connector; 901-Shouldered hexagonal nut; 902-Screw-in threaded bushing; 903-Adjusting bolt; 10-Fourth connector; 11-Compression spring; 12-First washer; 13-Second washer. Detailed Implementation

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] The present invention will now be described in further detail with reference to the accompanying drawings:

[0038] See Figure 1 This invention discloses a machining fixture for the mating surface of an embedded horizontal flange split housing, comprising a second adapter 4, a first adapter 3, and a base 1 connected sequentially from top to bottom. The base 1, the second adapter 4, and the first adapter 3 are all semi-annular structures, and the radii of the second adapter 4 and the first adapter 3 are the same as the top radius of the base 1. Several pressure plates for fixing the housing to be machined are provided on the second adapter 4, the first adapter 3, and the base 1, with the pressure plates positioned near the mating surface of the housing. This invention increases the rigidity of the clamping force by applying force to the housing's internal shape from different levels through a layered internal clamping structure. See the semi-housing structure for details. Figure 3 and Figure 4 By pressing key parts with several pressure plates, vibration caused by excessive part height during processing is effectively reduced, preventing the formation of vibration marks and ensuring the surface roughness of the mating surfaces. Preferably, the base 1, the first adapter 3, and the second adapter 4 are all made of cast iron HT200 and undergo aging treatment.

[0039] In one feasible embodiment of the present invention, the base 1 is a semi-annular stepped structure with an upper diameter smaller than a lower diameter, and has a positioning stop for positioning the inner circle of the casing to be processed. In this embodiment, the base 1 is a cast structure, a semi-annular chassis, and a positioning stop is designed on the base 1 to ensure the positioning of the inner circle of the part and to achieve axial and radial support. The perpendicularity of the positioning circle of the stop to the reference bottom surface is required to be 0.02, and the parallelism of the positioning surface of the stop to the bottom surface of the base is required to be 0.02.

[0040] In one feasible embodiment of the present invention, the pressure plate includes a first pressure plate 2, a second pressure plate 5, and a third pressure plate 6; the first pressure plate 2 is located on both sides of the lower part of the second adapter seat 4 and the first adapter seat 3, and is used to press the inner annular groove of the machine housing to be processed; the second pressure plate 5 is located on both sides of the top of the second adapter seat 4, and is used to press the upper mounting edge of the machine housing to be processed; the third pressure plate 6 is located on both sides of the middle step of the base 1, and is used to press the lower mounting edge of the machine housing to be processed.

[0041] In one feasible embodiment of the present invention, the first pressure plate 2 is connected to the second adapter 4 or the first adapter 3 via a second connector 8. A compression spring 11 and a second washer 13 are also provided between the second connector 8 and the second adapter 4 or the first adapter 3. The second pressure plate 5 is a movable wide-head pressure plate used to press the mounting edge of the part to prevent vibration caused by excessive height during processing. It is designed in the form of a hook, with a circular arc stop that matches the outer circle of the mounting edge on the part. During installation, the outer circle of the mounting edge on the part is also restricted, further strengthening the clamping rigidity of the part and preventing vibration. The second pressure plate 5 is connected to the top of the second adapter 4 via a third connector 9; the first adapter 3 is fixed to the base 1 via a first connector 7; the second adapter 4 is fixed to the first adapter 3 via the first connector 7, and a first washer 12 is provided between the first connector 7 and the first adapter 3 or the second adapter 4; several fourth connectors 10 are also installed on the step in the middle of the base 1. Both the first connector 7 and the second connector 8 are bolts. The fourth connector 10 includes an eye bolt and an eye bushing.

[0042] In one feasible embodiment of the present invention, the third connector 9 includes an adjusting bolt 903 located at one end of the second pressure plate 5 and a bolt located in the middle of the second pressure plate 5. The bolt is connected to the top of the second adapter 4 through a shouldered hexagonal nut 901 and a screw-in threaded bushing 902.

[0043] A method for machining the mating surface of an embedded horizontal flange split housing, based on the aforementioned machining fixture for the mating surface of an embedded horizontal flange split housing, includes the following steps:

[0044] S1, see S1 Figure 2 The machine casing parts to be processed are clamped on the fixture, and the runout of the mating surface is detected by dial gauge along the machine casing axis. Areas with runout values ​​greater than the preset threshold are welded.

[0045] S101. First, clean the machine tool worktable, the bottom surface of the fixture, the positioning surface of the fixture, and the positioning surface of the part.

[0046] S102, clamp the part on the fixture, and straighten the middle position of the parting surface to within 0.05 on both sides.

[0047] S103, along the axial direction of the casing, use a dial indicator to check the vertical runout from top to bottom. The vertical runout value should not exceed the preset threshold of 0.5. If the detected runout is greater than 0.5, mark the area on the mating surface where the runout exceeds 0.5mm (the recessed area) with a marker and perform weld overlay on the mating surface.

[0048] S104, weld overlay separation surface ( Figure 5 As shown in the image, the black shaded area represents the weld overlay area.

[0049] 1) Sand the part to be welded as shown in the diagram, and clean the sanded area with acetone.

[0050] 2) Perform welding on a portion of the mating surface. The welded area should be at least 0.5mm higher than other parts of the mating surface.

[0051] Welding wire grade: H1Cr12Ni3Mo2CoVA, diameter Φ2-Φ3. Welding current: (positive polarity) 90~110 (A); Tungsten electrode material: cerium tungsten; Tungsten electrode diameter: φ3.2mm; Arc length: 1~2 (mm); Current ramp-up time: 0.5~1.5 (s); Current decay time: 2~4 (s) for a single current, 8~10 (s) for a total current; Argon flow rate: 8~15 (L / min); Pre-conductor gas flow 0.5~1 (s), Post-conductor gas flow 8~10 (s).

[0052] 3) Remove weld beads and high points from the large end face and the inner circle of the stop, without damaging the base material.

[0053] This step depends on the actual deformation of the part. If the deformation of the mating surface is small, welding may not be required.

[0054] S2, Use a feeler gauge to check and ensure that the housing parts to be processed are clamped on the fixture;

[0055] The part is placed on the fixture with its large end face. It should be checked with a 0.03mm feeler gauge. If it cannot pass through, the pressure plate must be filled with copper sheet. When the part is pressed with the pressure plate, a pressure gauge should be placed on the upper part of the longitudinal mating surface of the casing to observe whether the part is deformed when it is pressed. If necessary, the pressing force or pressing position of the pressure plate should be adjusted.

[0056] Use a shim to padded the loose parts of the positioning surface of the pressure plate to press it in place, and then press the upper and lower flange edges together.

[0057] The runout is measured along the axial direction of the casing mating surface from top to bottom using a dial indicator; the runout should not exceed 0.3.

[0058] S3, rough boring and fine boring are performed sequentially on the mating surfaces of the housing to be machined;

[0059] S301, coarse boring of the joint surface

[0060] 1) Change the conventional milling method to a boring method to reduce cutting force and machining chatter, and improve machining accuracy.

[0061] The cutting tool is a φ80 single-edged boring bar with a cutting tip radius of R0.2-R0.4, a cutting speed of 85-100 mm / min, a feed rate of 100-120 mm / min, and a depth of cut of not less than 2 / 3 of the cutting tip radius.

[0062] 2) Leave a 0.2mm allowance for finishing during rough boring.

[0063] 3) The tool path is along the axial direction of the housing's opening and closing surfaces from the top to the bottom.

[0064] 4) Set the coordinate origin for CNC machining: X-axis zero point at the center of the part; Z-axis zero point at the joint surface; Y-axis zero point at the upper end of the small end; straighten the joint surface of the part and set the angular direction.

[0065] S302, precision boring of the joint surface

[0066] 1) After rough boring and milling the longitudinal mating surface, loosen the pressure plate, re-clamp and align the parts, and gently tighten them.

[0067] 2) Use a φ80 single-edged boring tool for boring and finishing the plane.

[0068] 3) When all mating surfaces are exposed to light, the total allowance removed from the parts must not exceed 0.5mm.

[0069] 4) The blade tip radius is R0.2-R0.4, the cutting speed is 75-95 mm / min, the feed is 100-120 mm / min, the depth of cut is not less than 1 / 3 of the blade tip radius, and the tool path is from the top to the bottom along the axial direction of the housing split surface.

[0070] 5) The time interval between the rough boring and fine boring joint surfaces shall not exceed 1 hour.

[0071] S4. Remove the machined casing from the fixture and scrape the mating surfaces of the casing.

[0072] S401, Disassembly: Disassemble the parts and clean away the metal filings.

[0073] S402, Scraping the mating surface: Use a scraper to scrape the mating surface.

[0074] S5. Perform a color check and feeler gauge check on the scraped casing mating surface. If the color check or feeler gauge check fails, the casing mating surface is scraped again.

[0075] a) The pigment for colorimetric testing, red lead powder (lead tetroxide), and machine lubricating oil (8A) are prepared in a weight ratio of 8:2;

[0076] b) The prepared colorant is evenly coated onto the working surface of the coloring gauge using a suede transfer bag, without forming clumps, agglomerations, or drips;

[0077] c) Place the working surface of the color gauge against the end face of the part to be inspected, without allowing relative rotation. Gently tap the color gauge with a wooden or rubber mallet to ensure good contact between the working surface of the color gauge and the end face of the part to be inspected, thus transferring the coating.

[0078] d) Color in segments, ensuring that the overlapping area of ​​the colors is not less than 20mm.

[0079] f) Place the mating surfaces of the parts on a platform and check the mating surfaces with a 0.05mm feeler gauge. There should be no through gaps.

[0080] If the coloring or feeler gauge inspection of the parting surface fails in this step, the parting surface will be scraped to complete the machining of half of the casing.

[0081] Machin the other half of the housing using the method described above. Ensure both halves of the housing are in the same position during clamping and inspection. Maintain consistent alignment when setting the CNC machining coordinate origin for both halves of the housing.

[0082] This invention solves the problems of large deformation and high machining difficulty on the mating surfaces of large casings, and addresses the issues of vibration and difficulty in ensuring accuracy using conventional methods. It completely eliminates the vibration phenomenon, achieving a surface roughness of 1.6 directly, and ensuring good perpendicularity between the machined surface and the end face. This improves the pass rate of colorimetric inspection of mating surfaces for parts such as high-pressure casings, creates a better condition for scraping the mating surfaces, and reduces the workload of subsequent grinding. It achieves stable machining of the casing mating surfaces, meeting the machining requirements of the parts. This method can be applied to the machining of mating surfaces of various types of split casings.

[0083] Example 1:

[0084] This embodiment takes the machining of the splitting and mating surface of the low-pressure compressor of a certain type of gas turbine as an example, and includes the following machining steps:

[0085] (1) The equipment uses a SPEEDMAT HP 2A machining center with a Siemens 840D operating system;

[0086] (2) Clean the machine tool worktable, the bottom surface of the fixture, the positioning surface of the fixture, and the positioning surface of the part. Clamp the part on the fixture and straighten the middle position of the parting surface to within 0.05 on both sides.

[0087] (3) Check the runout along the axial direction of the casing from top to bottom using a dial indicator. The vertical runout value should not exceed 0.5. If the runout is greater than 0.5, mark the area (recessed area) on the mating surface where the runout exceeds 0.5 mm with a marker.

[0088] (4) Sand the parts to be welded as shown in the diagram, and clean the sanded area with acetone. Perform weld overlay on the part of the parting surface. The weld overlay area should be at least 0.5mm higher than other parts of the parting surface. Remove weld beads and high points from the large end face and the inner circle of the stop, without damaging the base material.

[0089] (5) Place the part on the fixture with its large end face. Check with a 0.03mm feeler gauge. If it cannot pass through, the pressure plate must be filled with copper sheet. When clamping the part with the pressure plate, press a gauge on the upper part of the longitudinal mating surface of the casing to observe whether the part is deformed when clamping. If necessary, adjust the clamping force or clamping position of the pressure plate. Fill the loose part of the clamping position positioning surface of the pressure plate with a shim and clamp the upper and lower flange edges. Check the runout along the axial direction of the mating surface of the casing from top to bottom with a gauge. The runout should not be greater than 0.3.

[0090] (6) The mating surface is rough machined by boring the plane with a φ80 boring bar. Tool holder number: 80A07RS90ED14D, insert number: R390-170408M-PM 1130; cutting speed: 85mm / min, feed: 100mm / min, rough boring leaves a allowance of 0.2mm for finishing. The tool path is along the axial direction of the mating surface of the housing from the top to the bottom. Set the origin of CNC machining: with the large end of the part facing down, the X-axis zero point is at the center of the part, the Z-axis zero point is at the mating surface, and the Y-axis zero point is at the upper end of the small end. Straighten the mating surface of the part and set the angle.

[0091] (7) The mating surface is finished by boring the plane with a φ80 boring bar. Tool holder number: 80A07RS90ED14D, insert number: R390-170408M-PM 1130; cutting speed: 75mm / min, feed rate: 100mm / min, cutting depth: about 0.2mm. The tool path is along the axial direction of the mating surface of the housing from the top to the bottom.

[0092] (8) Disassembly: Disassemble the parts and clean up the iron filings.

[0093] (9) Scraping the joint surface: Use a scraper to scrape the joint surface.

[0094] (10) Colorimetric inspection:

[0095] a) The pigment for colorimetric testing, red lead powder (lead tetroxide), and machine lubricating oil (8A) are prepared in a weight ratio of 8:2;

[0096] b) The prepared colorant is evenly coated onto the working surface of the coloring gauge using a suede transfer bag, without forming clumps, agglomerations, or drips;

[0097] c) Place the working surface of the color gauge against the end face of the part to be inspected, without allowing relative rotation. Gently tap the color gauge with a wooden or rubber mallet to ensure good contact between the working surface of the color gauge and the end face of the part to be inspected, thus transferring the coating.

[0098] d) Color in segments, ensuring that the overlapping area of ​​the colors is not less than 20mm.

[0099] (11) Machin the other half of the housing as described above. When setting the origin of the CNC machining coordinates for both halves of the housing, keep the alignment consistent.

[0100] Example 2:

[0101] This embodiment takes the machining of the splitting and mating surface of the low-pressure compressor of a certain type of gas turbine as an example, and includes the following machining steps:

[0102] (1) The equipment uses a SPEEDMAT HP 2A machining center with a Siemens 840D operating system;

[0103] (2) Clean the machine tool worktable, the bottom surface of the fixture, the positioning surface of the fixture, and the positioning surface of the part. Clamp the part on the fixture and straighten the middle position of the parting surface to within 0.05 on both sides.

[0104] (3) Check the runout along the axial direction of the casing from top to bottom using a dial indicator. The vertical runout value should not exceed 0.5. If the runout is greater than 0.5, mark the area (recessed area) on the mating surface where the runout exceeds 0.5 mm with a marker.

[0105] (4) Sand the parts to be welded as shown in the diagram, and clean the sanded area with acetone. Perform weld overlay on the part of the parting surface. The weld overlay area should be at least 0.5mm higher than other parts of the parting surface. Remove weld beads and high points from the large end face and the inner circle of the stop, without damaging the base material.

[0106] (5) Place the part on the fixture with its large end face. Check with a 0.03mm feeler gauge. If it cannot pass through, the pressure plate must be filled with copper sheet. When clamping the part with the pressure plate, press a gauge on the upper part of the longitudinal mating surface of the casing to observe whether the part is deformed when clamping. If necessary, adjust the clamping force or clamping position of the pressure plate. Fill the loose part of the clamping position positioning surface of the pressure plate with a shim and clamp the upper and lower flange edges. Check the runout along the axial direction of the mating surface of the casing from top to bottom with a gauge. The runout should not be greater than 0.3.

[0107] (6) The mating surface is rough machined by boring the plane with a φ80 boring bar. Tool holder number: 80A07RS90ED14D, insert number: R390-170408M-PM 1130; cutting speed: 90mm / min, feed: 110mm / min, rough boring leaves a allowance of 0.2mm for finishing. The tool path is along the axial direction of the mating surface of the housing from the top to the bottom. Set the origin of CNC machining: with the large end of the part facing down, the zero point of the X-axis is at the center of the part, the zero point of the Z-axis is at the mating surface, and the zero point of the Y-axis is at the upper end of the small end. Straighten the mating surface of the part and set the angular direction.

[0108] (7) The mating surface is finished by boring the plane with a φ80 boring bar. Tool holder number: 80A07RS90ED14D, insert number: R390-170408M-PM 1130; cutting speed: 80mm / min, feed rate: 120mm / min, cutting depth: about 0.2mm. The tool path is along the axial direction of the mating surface of the housing from the top to the bottom.

[0109] (8) Disassembly: Disassemble the parts and clean up the iron filings.

[0110] (9) Scraping the joint surface: Use a scraper to scrape the joint surface.

[0111] (10) Colorimetric inspection:

[0112] a) The pigment for colorimetric testing, red lead powder (lead tetroxide), and machine lubricating oil (8A) are prepared in a weight ratio of 8:2;

[0113] b) The prepared colorant is evenly coated onto the working surface of the coloring gauge using a suede transfer bag, without forming clumps, agglomerations, or drips;

[0114] c) Place the working surface of the color gauge against the end face of the part to be inspected, without allowing relative rotation. Gently tap the color gauge with a wooden or rubber mallet to ensure good contact between the working surface of the color gauge and the end face of the part to be inspected, thus transferring the coating.

[0115] d) Color in segments, ensuring that the overlapping area of ​​the colors is not less than 20mm.

[0116] (11) Machin the other half of the housing as described above. When setting the origin of the CNC machining coordinates for both halves of the housing, keep the alignment consistent.

[0117] Example 3:

[0118] This embodiment takes the machining of the splitting and mating surface of the low-pressure compressor of a certain type of gas turbine as an example, and includes the following machining steps:

[0119] (1) The equipment uses a SPEEDMAT HP 2A machining center with a Siemens 840D operating system;

[0120] (2) Clean the machine tool worktable, the bottom surface of the fixture, the positioning surface of the fixture, and the positioning surface of the part. Clamp the part on the fixture and straighten the middle position of the parting surface to within 0.05 on both sides.

[0121] (3) Check the runout along the axial direction of the casing from top to bottom using a dial indicator. The vertical runout value should not exceed 0.5. If the runout is greater than 0.5, mark the area (recessed area) on the mating surface where the runout exceeds 0.5 mm with a marker.

[0122] (4) Sand the parts to be welded as shown in the diagram, and clean the sanded area with acetone. Perform weld overlay on the part of the parting surface. The weld overlay area should be at least 0.5mm higher than other parts of the parting surface. Remove weld beads and high points from the large end face and the inner circle of the stop, without damaging the base material.

[0123] (5) Place the part on the fixture with its large end face. Check with a 0.03mm feeler gauge. If it cannot pass through, the pressure plate must be filled with copper sheet. When clamping the part with the pressure plate, press a gauge on the upper part of the longitudinal mating surface of the casing to observe whether the part is deformed when clamping. If necessary, adjust the clamping force or clamping position of the pressure plate. Fill the loose part of the clamping position positioning surface of the pressure plate with a shim and clamp the upper and lower flange edges. Check the runout along the axial direction of the mating surface of the casing from top to bottom with a gauge. The runout should not be greater than 0.3.

[0124] (6) The mating surface is rough machined by boring the plane with a φ80 boring bar. Tool holder number: 80A07RS90ED14D, insert number: R390-170408M-PM 1130; cutting speed: 100mm / min, feed: 120mm / min, rough boring leaves a allowance of 0.2mm for finishing. The tool path is along the axial direction of the mating surface of the housing from the top to the bottom. Set the origin of CNC machining: with the large end of the part facing down, the zero point of the X-axis is at the center of the part, the zero point of the Z-axis is at the mating surface, and the zero point of the Y-axis is at the upper end of the small end. Straighten the mating surface of the part and set the angle.

[0125] (7) The mating surface is finished by boring the plane with a φ80 boring bar. Tool holder number: 80A07RS90ED14D, insert number: R390-170408M-PM 1130; cutting speed: 90mm / min, feed rate: 110mm / min, cutting depth: about 0.2mm. The tool path is along the axial direction of the mating surface of the housing from the top to the bottom.

[0126] (8) Disassembly: Disassemble the parts and clean up the iron filings.

[0127] (9) Scraping the joint surface: Use a scraper to scrape the joint surface.

[0128] (10) Colorimetric inspection:

[0129] a) The pigment for colorimetric testing, red lead powder (lead tetroxide), and machine lubricating oil (8A) are prepared in a weight ratio of 8:2;

[0130] b) The prepared colorant is evenly coated onto the working surface of the coloring gauge using a suede transfer bag, without forming clumps, agglomerations, or drips;

[0131] c) Place the working surface of the color gauge against the end face of the part to be inspected, without allowing relative rotation. Gently tap the color gauge with a wooden or rubber mallet to ensure good contact between the working surface of the color gauge and the end face of the part to be inspected, thus transferring the coating.

[0132] d) Color in segments, ensuring that the overlapping area of ​​the colors is not less than 20mm.

[0133] (11) Machin the other half of the housing as described above. When setting the origin of the CNC machining coordinates for both halves of the housing, keep the alignment consistent.

[0134] 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 machining fixture for the mating surfaces of an embedded horizontal flange split housing, characterized in that, The system includes a second adapter (4), a first adapter (3), and a base (1) connected sequentially from top to bottom. The base (1), the second adapter (4), and the first adapter (3) are all semi-annular structures, and the radii of the second adapter (4) and the first adapter (3) are the same as the top radius of the base (1). The second adapter (4), the first adapter (3), and the base (1) are all provided with several pressure plates for fixing the machine housing to be processed. The pressure plates are located near the joint surface of the machine housing to be processed. The base (1) is a semi-annular stepped structure with an upper diameter smaller than the lower diameter and has a positioning stop for positioning the inner circle of the machine housing to be processed. The pressure plates include a first pressure plate (2), a second pressure plate (5), and a third pressure plate (6). The first pressure plate (2) is located below the second adapter (4) and the first adapter (3). On both sides, there are inner annular grooves for pressing the machine casing to be processed; the second pressure plate (5) is located on both sides of the top of the second adapter (4) for pressing the upper mounting edge of the machine casing to be processed; the third pressure plate (6) is located on both sides of the middle step of the base (1) for pressing the lower mounting edge of the machine casing to be processed; the second pressure plate (5) is a movable wide-head pressure plate, and the second pressure plate (5) is connected to the top of the second adapter (4) through the third connector (9); the first adapter (3) is fixed to the base (1) through the first connector (7); the second adapter (4) is fixed to the first adapter (3) through the first connector (7), and a first washer (12) is provided between the first connector (7) and the first adapter (3) or the second adapter (4); several fourth connectors (10) are also installed on the middle step of the base (1).

2. The machining fixture for the mating surface of an embedded horizontal flange split housing according to claim 1, characterized in that, The first pressure plate (2) is connected to the second adapter (4) or the first adapter (3) by a second connector (8). A compression spring (11) and a second washer (13) are also provided between the second connector (8) and the second adapter (4) or the first adapter (3).

3. The machining fixture for the mating surface of an embedded horizontal flange split housing according to claim 1, characterized in that, The third connector (9) includes an adjusting bolt (903) located at one end of the second pressure plate (5) and a bolt located in the middle of the second pressure plate (5). The bolt is connected to the top of the second adapter (4) by a shouldered hexagonal nut (901) and a screw-in threaded bushing (902).

4. A method for machining the mating surface of an embedded horizontal flange split casing, characterized in that, A machining fixture for the mating surface of an embedded horizontal flange split housing according to any one of claims 1 to 3 includes the following steps: The housing part to be processed is clamped on the fixture, and the runout of the mating surface is detected by dial indicator along the axial direction of the housing. Areas with runout values ​​greater than the preset threshold are welded. Use a feeler gauge to check and ensure that the housing parts to be processed are clamped on the fixture; The mating surfaces of the casing to be machined are successively rough-bored and finish-bored; The machined casing is removed from the fixture, and the mating surfaces of the casing are scraped to complete the machining process.

5. The method for machining the mating surface of an embedded horizontal flange split casing according to claim 4, characterized in that, The preset threshold for the fluctuation value is 0.

05.

6. The method for machining the mating surface of an embedded horizontal flange split casing according to claim 4, characterized in that, The rough boring has a cutting speed of 85 mm / min to 100 mm / min, a feed rate of 100 mm / min to 120 mm / min, and a depth of cut of not less than 2 / 3 of the tool tip radius; the finish boring has a cutting speed of 75 mm / min to 95 mm / min, a feed rate of 100 mm / min to 120 mm / min, and a depth of cut of not less than 1 / 3 of the tool tip radius; the time interval between rough boring and finish boring does not exceed 1 hour.

7. The method for machining the mating surface of an embedded horizontal flange split casing according to claim 4, characterized in that, The steps of removing the processed casing from the fixture and scraping the casing's mating surfaces to complete the processing also include: performing a color check and a feeler gauge check on the scraped casing's mating surfaces. If the color check or feeler gauge check fails, the casing's mating surfaces are scraped again.

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