A method for processing a three-dimensional complex cross-flame tube with flanges

Abstract

The present invention discloses a method for processing a three-dimensional, complex cross-fire tube with a flange, comprising the following steps: preparing a blank tube, beveling, first flanging, heat treatment, second flanging, heat treatment, correcting the flanging, cutting a straight end face, forming the cross-fire tube bend profile, and turning the flanging to obtain the flange outer diameter and the straight end face. During the processing, a die with a split rigid structure is used in conjunction with a urethane punch to ensure the dimensional accuracy of the part profile. The cutting parameters are adjusted to ensure the accuracy of the part's shape, and the final shape of the cross-fire tube is obtained by turning. The present invention reduces the processing cost of three-dimensional, complex cross-fire tubes with flanges and similar structural parts, shortens the processing cycle, improves processing efficiency, and improves part quality and pass rate.

Description

Technical Field

[0001] The invention belongs to the technical field of aero-engine processing, and in particular relates to a processing method for a cross-fire tube of an aero-engine. Background Art

[0002] like Figure 1 The cross-fire tube shown is a hot end component of an aircraft engine. It is a thin-walled elbow adapter with a flange, similar to an elbow adapter. The included angle is α°, and the outlet size at both ends of the tube is ΦD. +0 0 .56 The flange is a flange flange with a diameter of Φd1 and a center of the circle along the back center of the "bend tube". The flange has an angle of α1° with the plane perpendicular to the axis of the cross-flame tube. The part surface is complex and one weld is allowed along the main line. The material thickness is 1.5mm, and the flange is allowed to be locally thinned to 1.08mm. The part material is GH3044. The sheet material is wrinkled after welding. The traditional rigid mold cannot achieve the bending of the tube material. If it is welded after forming, it is difficult to grind the weld and correct the welding deformation. Since the part is a smooth transition curve, it is extremely mobile during the shape processing, which makes it difficult to achieve the consistency of the part shape processing surface, the consistency of the overall flange, and the difficulty of part surface detection. Ultimately, it leads to high processing costs, long processing cycles, low processing efficiency, poor quality and pass rate of the parts. Based on the above problems, it is urgent to develop a reasonable and feasible processing method to process similar parts. Summary of the Invention

[0003] In response to the problems described in the background technology, the present invention aims to provide a method for processing a three-dimensional complex cross-flame tube with a flange, which can reduce processing costs, shorten processing cycles, improve efficiency, and enhance part quality and qualification rate.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for processing a three-dimensional complex cross-fire tube with a flange, comprising the following steps:

[0006] Step 1: Prepare the blank tube material. The blank tube material is processed from rectangular sheet material, and is bent, pipe-formed, welded and heat-treated in a pipe-making die in sequence, and finally the rectangular sheet material is prepared into a straight blank tube material;

[0007] Step 2: Bevel the straight end face of the blank tube and make a bevel process to form the flange.

[0008] Step 3: The first flanging is performed by positioning the other axial straight end face of the blank tube material, and flanging the beveled end face after the bevel treatment in step 2 is performed. No cracks are allowed to form on the flanging edge.

[0009] Step 4: Heat treatment to remove the stress caused by flanging;

[0010] Step 5: Flanging for the second time: Continue to increase the flanging angle based on the first flanging of the oblique end face in step 3. No cracks are allowed on the flanging edge.

[0011] Step 6: Heat treatment to remove the stress caused by flanging;

[0012] Step 7: Correct the flange surface so that the flange profile meets the flange requirements in the drawing;

[0013] Step 8: Cutting: Cut the straight end surface used for positioning in step 3, ensuring the angle α between the flange and the straight end surface in the drawing;

[0014] Step 9: Forming, forming the curved tube surface in the cross-fire tube on the straight blank tube material, ensuring that the inner cavity diameter of the blank tube material after forming is equal to the inner diameter ΦD of the cross-fire tube;

[0015] Step 10: Turn the outer diameter of the flange to make it equal to the outer diameter of the flange;

[0016] Step 11: Turn the straight end surface cut in step 8.

[0017] further,

[0018] In the step 1, the length of the blank tube material is the longest axial dimension of the cross-fire tube after being straightened and unfolded along the axis plus a margin, and the diameter is smaller than the aperture of the cross-fire tube. The blank tube material is unfolded into a rectangular sheet material through the neutral layer, and the sheet material is cut by a shearing machine to ensure that the sheet material has right angles on all sides;

[0019] In the step 1, after the sheet is welded by argon arc welding, the roundness is corrected and heat treatment is performed to remove welding stress.

[0020] further,

[0021] In step 2, a grinding wheel cutter is used to cut the weld of the blank pipe material in step 1 as the highest point of the cutting to perform bevel processing;

[0022] In step 2, after beveling, burrs generated by cutting are removed, and the highest point and the lowest point of the cutting are rounded and polished within a range of a certain distance offset to the left and right.

[0023] further,

[0024] In step 3, before the first flanging, varnish is sprayed on the inner and outer surfaces of the blank tube material for lubrication, and the equipment for the first flanging is a hydraulic press;

[0025] The heat treatment in step 4 is solution treatment;

[0026] In step 5, before the second flanging, varnish is sprayed on the inner and outer surfaces of the blank tube for lubrication. The first flanging equipment is a hydraulic press, which uses the straight end surface of the blank tube for positioning and the inner wall of the blank tube as support;

[0027] The heat treatment in step 6 is solution treatment.

[0028] further,

[0029] In step 7, varnish is sprayed on the inner and outer surfaces of the blank tube for lubrication. The correction equipment is a hydraulic press, which uses the straight end surface of the blank tube to position the inner wall of the blank tube as support to flatten the flange and correct the flange surface to be consistent with the flange surface of the cross-fire tube.

[0030] In step 7, there is a mark line at the molding high point of the correction mold. When the blank tube is corrected, the weld is aligned with the mark line of the correction mold.

[0031] In step 7, the angle after flanging correction is smaller than the final angle α1.

[0032] further,

[0033] In step 8, cutting is performed using a cutting fixture with a score line on it. The flange is used as a support, the weld is aligned with the score line on the cutting fixture, and a grinding wheel is used to cut the straight end surface of the blank tube material to ensure that the angle α between the flange and the straight end surface is maintained.

[0034] In step 8, after cutting is completed, burrs around the blank tube are removed.

[0035] further,

[0036] In step 9, the forming equipment is a hydraulic press, the blank tube is placed in a forming die, and the weld is aligned with the engraved line on the forming die;

[0037] In step 9, the convex mold of the forming mold is made of cylindrical urethane, the diameter of the cylindrical urethane can be smoothly loaded into the inner cavity of the blank tube material, and the length is greater than the total length of the blank tube material. The concave mold of the forming mold is a split-type rigid mold. The convex mold is extruded by the downward extrusion device. The convex mold squeezes the inner wall of the blank tube material so that the outer wall of the blank tube material fits the concave mold to achieve the overall surface forming of the cross-fire tube;

[0038] In step 9, after forming, a line is drawn on the flange along the parting surface of the female mold of the forming mold, which serves as a reference line for subsequent flange external shape processing;

[0039] In step 9, after forming, the flatness of the flange is ensured while ensuring that the steel ball with an outer diameter of ΦD passes smoothly through the inner cavity of the blank tube material.

[0040] further,

[0041] In step 10, when turning the outer diameter of the flange, the inner end face of the flange is supported and positioned with the inner cavity surface of the blank tube material, the outer end face of the flange is pressed, and then the circumferential surface of the flange is turned to obtain the outer diameter of the flange, and the burrs on the edge of the flange are removed.

[0042] further,

[0043] In step 11, when turning the straight end face, the inner end face of the flange is pressed, positioned and clamped according to the shape of the blank tube material, and the straight end face of the blank tube material is turned;

[0044] In step 11, after the straight end face is turned, it is inspected by using the cross-fire tube in working state, respectively tightening the flange end face and the straight end face, and inspecting the outer diameter of the flange and the angle between the flange and the straight end face.

[0045] Compared with the prior art, the present invention proposes a method for processing aero-engine cross-fire tubes, which first processes the flange to obtain the basic shape of the flange, then cuts the straight end face to obtain the required angle between the flange and the straight end face, and then shapes the curved surface of the cross-fire tube. Finally, the flange and the straight end face are turned separately to reach the final size. During the forming process of the curved surface, the part surface dimensional accuracy is ensured by forming the die with a rigid structure of petals in combination with the urethane punch. By adjusting the cutting parameters, the part shape accuracy is ensured. Compared with the method of forming first and then welding, there is no need to spend a lot of time on weld grinding and deformation correction, which greatly improves labor efficiency. At present, the processing method of the present invention has been used on site and has achieved the purpose of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is the main view of the cross-fire tube;

[0047] Figure 2 yes Figure 1 Middle AA section cutaway view;

[0048] Figure 3 yes Figure 2 A magnified view of a part I of the sectional view of section AA;

[0049] Figure 4 This is a structural diagram of a forming die for forming the curved tube profile in a combined flame tube;

[0050] In the figure: 1- liner; 2- punch; 3- reinforcement ring; 4- die; 5- upper template; 6- lower template; 7- ejector rod; 8- spacer block; 9- top plate. DETAILED DESCRIPTION

[0051] The present invention is further described below with reference to the accompanying drawings and specific embodiments. However, it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various modifications, substitutions and changes made according to common technical knowledge and customary means in the field are included in the scope of the present invention.

[0052] In order to process Figures 1 to 3 The present invention designs a method for processing a complex cross-fire tube with a flange in a three-dimensional space as shown below, comprising the following steps:

[0053] Step 1: Prepare the blank tube material. The blank tube material is processed from rectangular sheet material. After the shearing machine cuts the material, it is bent, pipe-formed, welded, and heat-treated with a tube-making die to ensure the plasticity of the blank tube material. That is, after cutting the rectangular sheet material, the two ends are bent and welded to form a straight tube, and then heat-treated to ensure the plasticity;

[0054] Step 2: Bevel cutting: bevel one axial straight end face of the blank tube;

[0055] Step 3: For the first flanging, the other axial straight end face of the blank tube is used for positioning, and the angled beveled edge after bevel processing is flanging. No cracks are allowed on the flanging edge.

[0056] Step 4: Heat treatment to remove the stress caused by flanging;

[0057] Step 5: Flanging for the second time, increase the angle of the first flange, and no cracks are allowed on the flange edge;

[0058] Step 6: Heat treatment to remove the stress caused by flanging;

[0059] Step 7: Correction: Correct the overall profile of the flanged H surface to meet the requirements of the drawing;

[0060] Step 8: Cutting: Cut the axial straight end surface of the blank tube material used for positioning in step 3 to ensure an angle of α±0.5°;

[0061] Step 9: Forming: forming the curved tube surface of the cross-fire tube on the blank tube material to ensure that the steel ball with a diameter of ΦD can smoothly pass through the inner cavity of the blank tube material after forming, and marking the edge of the flange according to the mold marking line. The marking line serves as the reference line for subsequent processing;

[0062] Step 10: Turn the flange to obtain the outer diameter of the flange, align the engraved line of the blank tube with the engraved line of the turning fixture, and turn the flange to ensure that the diameter of the flange is equal to the designed outer diameter of the flange;

[0063] Step 11: Turn the straight end face, close to the flange, position it according to the shape of the blank tube, clamp the inner surface of the blank management, turn the straight end face M, and ensure that all dimensions meet the requirements of the cross-flame tube drawing.

[0064] Specifically, in step 1, when preparing the blank tube material, the length of the blank tube material is the longest dimension of the cross-fire tube after being unfolded along the axis plus a margin of 15 to 20 mm, and the diameter of the blank tube material is 2 to 3 mm smaller than the cross-fire tube aperture. The blank tube material is unfolded into a rectangular sheet through the neutral layer of the cross-fire tube, and the sheet material is cut by a shearing machine to ensure that the four vertex angles of the sheet material are right angles of 90°;

[0065] Specifically, after the blank tube material prepared in step 1 is welded by argon arc welding, the roundness is corrected to be no greater than 1, and heat treatment is performed to remove welding stress;

[0066] Specifically, in step 2, when cutting the bevel, the equipment used is a grinding wheel cutter. To ensure the consistency of the parts, the weld is set as the highest point of the cutting. To ensure that the flange diameter is greater than Φd1 and the flange width is reduced, the cutting angle can be leveled in the subsequent process to achieve angle processing and reduce the flange width. In this embodiment, the cutting angle is set to α1;

[0067] Specifically, after beveling in step 2, remove the burrs generated by cutting, and perform chamfering and polishing within a range of 15 mm to the left and right of the high and low points of the cutting;

[0068] Specifically, before the first flanging in step 3, varnish is sprayed on the inner and outer surfaces of the blank tube for lubrication. The flanging equipment is a 500KN hydraulic press. The flanging edge forms an angle of 30° with the center axis of the blank tube. The flanging transfer can be appropriately enlarged according to actual conditions.

[0069] Specifically, the heat treatment in step 4 is a solution treatment to soften the material and eliminate forming stress;

[0070] Specifically, before the second flanging in step 5, the inner and outer surfaces of the blank tube are sprayed with varnish for lubrication. The flanging equipment is a 500KN hydraulic press, which is positioned with a straight end face and supported by the inner wall of the blank tube. The flanging edge forms an angle of 60° with the center axis of the blank tube, and the flanging transfer is R4±1. The outer diameter after flanging is not less than Φd1-1mm;

[0071] Specifically, the heat treatment in step 6 is a solution treatment to soften the material and eliminate forming stress;

[0072] Specifically, before step 7 correction, the inner and outer surfaces of the blank tube are sprayed with varnish for lubrication. The correction equipment is a 500KN hydraulic press, which uses a straight end face for positioning and the inner wall of the blank tube for support. The flange is flattened and the flange H surface (the H surface is a flat surface) is corrected to be consistent with the final profile of the cross-fire tube. The outer diameter of the flange is not less than Φd1.

[0073] Specifically, in step 7, the correction mold has a scale line at the molding high point of the correction mold as a reference. When the blank tube is corrected, the weld is aligned with the scale line of the correction mold;

[0074] Specifically, in step 7, in order to ensure that the flange finally forms an angle α1 with the vertical plane of the axis of the blank tube, the flange correction angle is smaller, for example, an angle of α1-3°;

[0075] Specifically, in step 8, a cutting fixture is used for cutting. The cutting fixture has a cut line as a cutting reference. The weld is aligned with the cut line of the cutting fixture with the H surface (flat surface) of the flange as support. The straight end face is cut with a grinding wheel. The cutting angle α ensures that the lowest point size of the straight end face after cutting has a margin of 3 to 5 mm.

[0076] Specifically, in step 8, burrs around the blank tube are removed after cutting;

[0077] Specifically, the equipment used for forming in step 9 is a 2000KN hydraulic press. The blank pipe material is placed in the forming mold, and the weld is aligned with the mark line in the forming mold as a reference;

[0078] Specifically, the punch of the forming mold in step 9 is made of cylindrical urethane. The diameter of the cylindrical urethane is sufficient to be smoothly inserted into the inner hole of the blank tube material. The length of the cylindrical urethane is 15 to 20 mm longer than the total length of the blank tube material. The die of the forming mold is a split-type rigid die. The forming equipment moves downward to extrude the urethane punch, so that the outer wall of the blank tube material fits into the die to achieve the integral formation of the cross-fire tube bend profile.

[0079] Specifically, after forming in step 9, a line is drawn on the flange along the parting surface of the female mold of the forming mold as a reference line for subsequent shape processing;

[0080] Specifically, after forming in step 9, a steel ball with a diameter of ΦD needs to pass through its inner hole (inner cavity) smoothly, and at the same time, the flatness of the flange needs to be ensured to be no greater than 0.5;

[0081] Specifically, in step 10, the outer diameter of the flange is turned to obtain the final outer diameter of the flange, the H surface of the flange is supported, the profile A (the profile A already formed inside the blank tube material) is used for positioning, the outer end face (B face) of the flange is pressed, and the outer circle of the flange is turned to ensure that the outer diameter of the flange is obtained. At the same time, the score line is drawn in the thickness direction of the flange as a reference for turning the straight end face in step 11, and the edge burrs of the flange are removed;

[0082] Specifically, in step 11, when turning the end face, close to the H surface of the flange, align the engraved line on the blank tube with the engraved line on the turning fixture, position and clamp it according to the shape of the blank tube, and turn the straight end face M to ensure that all the external dimensions of the blank tube meet the drawing.

[0083] Specifically, when inspecting the parts after turning the end face in step 11, a simulated inspection is performed using the working state of the linked flame tube. The inner end face of the flange (H face) is on a gauge block with a diameter of Φd1, and a gauge block with an inclined end face (inclination angle of α±5′) and a diameter of ΦD+2t+2mm is used to support the straight end face (M face) to ensure that the outer edge of the H face does not exceed the Φd1 gauge block, and the gap between the M face and the ΦD+2t+2mm gauge block plane is not greater than 0.5. The part is then judged to be qualified.

[0084] Assumptions Figures 1 to 3 Where ΦD = 35 mm, Φd1 = 46.5 mm, α = 33° ± 0.5°, α1 = 22.5° ± 1°, L = 14.1 mm, and t = 1.5 mm, the method for machining a three-dimensional complex cross-fire tube with a flange includes the following steps:

[0085] Step 1: Prepare the blank tube material. The blank tube material is processed by plate. After the rectangular plate is cut by the shearing machine, it is bent, piped, welded and heat treated with a pipe making die to ensure the plasticity of the blank tube material. The outer diameter of the blank tube material is Φ36.5mm and the length is 45mm.

[0086] Step 2: Bevel cutting: cut one end of the blank tube into 22.5°±1°, with the highest point at the center of the weld. Remove the burrs produced by cutting, and polish and round the highest and lowest points within the range of 15-20mm.

[0087] Step 3: For the first flanging, position the straight end face of the blank tube, align the weld with the engraved line of the flanging die, and flanging the angled bevel edge. The length from the flanging point to the edge is 6-7mm. The flanging edge is at an angle of 30° to the center of the blank tube. Cracks are not allowed on the edge.

[0088] Step 4: Heat treatment to remove the stress caused by flanging;

[0089] Step 5: Flanging for the second time, increase the angle of the first flanging, align the center of the weld with the engraved line of the flanging die, and make the flanging edge form an angle of 60° with the center of the blank tube. No cracks are allowed on the flanging edge.

[0090] Step 6: Heat treatment to remove the stress caused by flanging;

[0091] Step 7: Correction: The center of the weld seam of the blank tube is aligned with the mark line of the correction die. The correction flange plane forms an angle of 19.5° with the plane perpendicular to the center axis of the blank tube, which is 3° smaller than the final target α1=22.5°. This reserves a certain amount of deformation (angle) for the subsequent forming in step 9. In step 9, the liner 1 and the die 4 clamp the flange to form while completing the correction of the remaining angle.

[0092] Step 8: Cutting: Align the center of the weld with the markings on the cutting fixture, cut the straight end face, ensure the angle is 33°±0.5°, and remove the burrs produced by cutting;

[0093] Step 9: Forming, align the weld center with the marking line of the forming mold, form the curved tube profile of the cross-fire tube, ensure that the steel ball with a diameter of Φ35.1 can smoothly pass through the inner cavity of the blank tube, and mark the flange surface according to the parting line of the mold as the reference for subsequent processing. Figure 4 The forming mold includes a liner 1, a punch 2, a reinforcement ring 3, a die 4, an upper template 5, a lower template 6, a push rod 7, a pad 8 and a top plate 9. The liner 1 is connected to the upper template 5 by screws, the inner hole of the liner 1 is filled with the punch 2, and a pad 8 is installed at the inner hole of the liner 1. The pad 8 is connected to the upper template 5 by screws. The lower end of the die 4 is placed on the lower template 6 through the top plate 9. The die 4 is split into multiple petals along the circumferential direction and constrained by the reinforcement ring 3 of the circumferential outer ring. The reinforcement ring 3 is a circular ring and is installed on the lower template 6 by screws. The push rod 7 is movably connected to the lower template 6, and the upper end of the push rod 7 is close to the top plate 9. The forming principle is: Figure 4 The thick black solid line in the middle is the part. The upper template 5 goes up until the punch 2 is completely separated from the die 4. The part with the second flanging is heat treated, corrected and cut and then placed into the die 4. The upper template 5 goes down to push the pad 8. The punch 2 completely fills the cavity of the die 4 under the extrusion pressure of the pad 8. Then the upper template 5 goes up, the push rod 7 goes up, and the top plate 9 goes up under the action of the push rod 7 to push the die 4 out of the reinforcement ring 3, completing the bending tube profile of the cross-flame tube. Because the cross-flame tube is a spatial profile, the die 4 adopts a petal structure to take out the formed parts. The die 4 is spliced ​​circumferentially with a multi-petal structure. Therefore, a reinforcement ring 3 is used on the outside of the die 4 to fix and constrain the die 4. Figure 3 The dimensions R1, R3 and R15 of the outer surface of the middle flange are achieved through the cooperation of the die 4, the punch 2 and the liner 1.

[0094] Step 10: Turn the outer diameter of the flange. Align the engraved line after the flange is formed in step 9 with the engraved line of the turning fixture. Turn the flange to ensure that the flange diameter is equal to the outer diameter of the flange in the drawing. Extend the engraved line on the flange surface in the thickness direction to remove the burrs caused by turning.

[0095] Step 11: Turn the end face straight, close to the flange, position and clamp the profile by the shape, align the scale line extending to the thickness direction in step 10 with the scale line of the turning fixture, turn the end face M, ensure all dimensions, and remove the burrs generated by turning.

[0096] Any matters not described in detail in the present specification are prior art known to those skilled in the art. Although the above description of the present invention is based on illustrative embodiments to facilitate understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the specific embodiments. As long as various modifications are within the spirit and scope of the present invention as defined and determined by the appended claims, such modifications will be obvious to those skilled in the art, and all inventions and creations utilizing the concepts of the present invention are protected.

Claims

1. A method for processing a three-dimensional complex cross-fire tube with a flange, characterized in that: The following steps are involved: Step 1: Prepare the blank tube material. The blank tube material is processed from rectangular sheet material, and is bent, pipe-formed, welded and heat-treated in a pipe-making die in sequence, and finally the rectangular sheet material is prepared into a straight blank tube material; Step 2: Bevel the first axial straight end face of the blank tube and make a bevel process to serve as the flange position; Step 3: The first flanging is performed by positioning the second axial straight end face of the blank tube material, and flanging the beveled end face after the bevel treatment in step 2 is performed. No cracks are allowed to form on the flanging edge. Step 4: Heat treatment to remove the stress caused by flanging; Step 5: Flanging for the second time: Continue to increase the flanging angle based on the first flanging of the oblique end face in step 3. No cracks are allowed on the flanging edge. Step 6: Heat treatment to remove the stress caused by flanging; Step 7: Correct the flange surface so that the flange profile meets the flange requirements in the drawing; Step 8: Cutting: Cut the second axial straight end surface used for positioning in step 3, ensuring the angle α between the flange and the second axial straight end surface in the drawing; Step 9: Forming, forming the curved tube surface in the cross-fire tube on the straight blank tube material, ensuring that the inner cavity diameter of the blank tube material after forming is equal to the inner diameter ΦD of the cross-fire tube; Step 10: Turn the outer diameter of the flange to make it equal to the outer diameter of the flange; Step 11: Turn the second axial straight end surface after cutting in step 8.

2. The method for machining a three-dimensional complex cross-fire tube with flange according to claim 1, characterized in that: In the step 1, the length of the blank tube material is the longest axial dimension of the cross-fire tube after being straightened and unfolded along the axis plus a margin, and the diameter is smaller than the aperture of the cross-fire tube. The blank tube material is unfolded into a rectangular sheet material through the neutral layer, and the sheet material is cut by a shearing machine to ensure that the sheet material has right angles on all sides; In the step 1, after the sheet is welded by argon arc welding, the roundness is corrected and heat treatment is performed to remove welding stress.

3. The method for machining a three-dimensional complex cross-fire tube with flange according to claim 1, characterized in that: In step 2, a grinding wheel cutter is used to cut the weld of the blank pipe material in step 1 as the highest point of the cutting to perform bevel processing; In step 2, after beveling, burrs generated by cutting are removed, and the highest point and the lowest point of the cutting are rounded and polished within a range of a certain distance offset to the left and right.

4. The method for machining a three-dimensional complex cross-fire tube with flange according to claim 1, characterized in that: In step 3, before the first flanging, varnish is sprayed on the inner and outer surfaces of the blank tube material for lubrication, and the equipment for the first flanging is a hydraulic press; The heat treatment in step 4 is solution treatment; In step 5, before the second flanging, varnish is sprayed on the inner and outer surfaces of the blank tube for lubrication. The first flanging equipment is a hydraulic press, which uses the second axial straight end surface of the blank tube for positioning, and the inner wall of the blank tube serves as support. The heat treatment in step 6 is solution treatment.

5. The method for machining a three-dimensional complex cross-fire tube with flange according to claim 1, characterized in that: In step 7, varnish is sprayed on the inner and outer surfaces of the blank tube for lubrication. The correction equipment is a hydraulic press. The second axial straight end surface of the blank tube is positioned, and the inner wall of the blank tube is used as support to flatten the flange. At the same time, the flange profile is corrected to be consistent with the cross-fire tube flange profile. In step 7, there is a mark line at the molding high point of the correction mold. When the blank tube is corrected, the weld is aligned with the mark line of the correction mold. In step 7, the angle after flanging correction is smaller than the final angle α1.

6. The method for machining a three-dimensional complex cross-fire tube with flange according to claim 1, characterized in that: In step 8, cutting is performed using a cutting fixture with a score line on it. The flange is used as a support, the weld is aligned with the score line on the cutting fixture, and the second axial straight end face of the blank tube is cut with a grinding wheel to ensure that the angle α between the flange and the second axial straight end face is ensured; In step 8, after cutting is completed, burrs around the blank tube are removed.

7. The method for machining a three-dimensional complex cross-fire tube with flange according to claim 1, characterized in that: In step 9, the forming equipment is a hydraulic press, the blank tube is placed in a forming die, and the weld is aligned with the engraved line on the forming die; In step 9, the convex mold of the forming mold is made of cylindrical urethane, the diameter of the cylindrical urethane can be smoothly loaded into the inner cavity of the blank tube material, and the length is greater than the total length of the blank tube material. The concave mold of the forming mold is a split-type rigid mold. The convex mold is extruded by the downward extrusion device. The convex mold squeezes the inner wall of the blank tube material so that the outer wall of the blank tube material fits the concave mold to achieve the overall surface forming of the cross-fire tube; In step 9, after forming, a line is drawn on the flange along the parting surface of the female mold of the forming mold, which serves as a reference line for subsequent flange external shape processing; In step 9, after forming, the flatness of the flange is ensured while ensuring that the steel ball with an outer diameter of ΦD passes smoothly through the inner cavity of the blank tube material.

8. The method for machining a three-dimensional complex cross-fire tube with flange according to claim 1, characterized in that: In step 10, when turning the outer diameter of the flange, the inner end face of the flange is supported and positioned with the inner cavity surface of the blank tube material, the outer end face of the flange is pressed, and then the circumferential surface of the flange is turned to obtain the outer diameter of the flange, and the burrs on the edge of the flange are removed.

9. The method for machining a three-dimensional complex cross-fire tube with flange according to claim 1, characterized in that: In step 11, when turning the second axially straight end surface, the inner end surface of the flange is pressed, positioned and clamped according to the outer shape of the blank tube material, and the second axially straight end surface of the blank tube material is turned; In step 11, after the second axial straight end face is turned, it is inspected by using the cross-fire tube in working state, respectively tightening the flange end face and the second axial straight end face, and checking the outer diameter of the flange and the angle between the flange and the second axial straight end face.

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