Machining method of spherical surface transfer titanium alloy barrel

Abstract

The invention relates to an aero-engine manufacturing technology, in particular to a processing method of a spherical surface transfer titanium alloy barrel, which comprises the following steps: S1, laser blanking: carrying out laser blanking on a plate to obtain a fan-shaped flat plate material; s2, edge rolling and welding are conducted, specifically, the fan-shaped flat plate material is subjected to edge rolling and welding, and a conical barrel blank is obtained; s3, hot bulging is conducted, specifically, the conical barrel blank is arranged on a hot bulging mold in a sleeving mode for hot bulging; s4, laser cutting is conducted, specifically, the large end and the small end of the part obtained after thermal bulging are subjected to laser cutting; and S5, acid pickling is conducted, specifically, the part obtained after laser cutting is subjected to acid pickling, and oxide skin on the surface of the part is removed. Compared with the prior art, the method provided by the invention has the advantages that the wrinkle problem of the part during halving forming is avoided, the forming wrinkle does not need to be manually knocked and repaired, the field processing strength is reduced, two-time thermal forming is reduced into one-time thermal forming, the part processing period is shortened, the part processing efficiency is improved, and the surface quality of the part is improved.

Description

Technical Field

[0001] The invention relates to aero-engine manufacturing technology, and in particular to a processing method for a spherical transition titanium alloy cylinder. Background Art

[0002] Combination Figure 1 , Figure 2 The figure shows the structure diagram of the titanium alloy cylinder of the second section of the outer wall of the aircraft engine. The material grade of the titanium alloy cylinder is TA15, and the material thickness is t=1mm. The small end of the part is a conical surface with an outer diameter of φD2 at the mouth; the large end is a cylindrical surface with an outer diameter of φD1. The conical surface and the cylindrical surface are connected through a spherical surface, and after the connection, the central axis of the conical surface and the center of the cylindrical surface form an angle α1, which is a typical spherical connection titanium alloy thin-walled cylinder part.

[0003] For the above-mentioned titanium alloy cylinder, the processing route of half-forming, welding and bulging is currently adopted for processing parts. During the process of half-hot forming of parts, a large number of wrinkles appear on the surface of the parts after forming, and even pile-up occurs, causing the parts to be scrapped. After the parts are welded into a cylinder and then bulged, some wrinkles are likely to remain on the parts after bulging, and the wrinkles need to be reduced by manual knocking. The surface quality of the parts is poor, the processing efficiency is low, and the on-site processing intensity is high. Summary of the invention

[0004] The main purpose of the present invention is to provide a processing method for a spherical transition titanium alloy cylinder, aiming to solve the above technical problems.

[0005] To achieve the above object, the present invention provides a method for processing a spherical transition titanium alloy cylinder, comprising the following steps:

[0006] S1. Laser cutting: Use the plate to cut by laser to obtain fan-shaped flat plate;

[0007] S2, rolling welding: rolling and welding the fan-shaped flat sheet to obtain a tapered tube blank;

[0008] S3, hot expansion: put the conical tube blank on the hot expansion mold for hot expansion;

[0009] S4, laser cutting: laser cutting of the large and small ends of the parts obtained after thermal expansion;

[0010] S5. Pickling: Pickle the parts obtained after laser cutting to remove the oxide scale on the surface of the parts.

[0011] Preferably, in step S1, a plurality of positioning holes are laser cut in the fan-shaped flat plate, and the positioning holes are arranged near the arc edge of the large end of the fan-shaped flat plate; the hot expansion mold includes a plurality of annularly evenly distributed expansion blocks, and pins are inserted into the expansion blocks; in step S3, after the conical tube blank is sleeved on the expansion block of the hot expansion mold, the pins are passed through the positioning holes and then inserted into the expansion block.

[0012] Preferably, in step S2, a reinforcing sheet is welded on the obtained conical tube blank, and the reinforcing sheet is welded at a position below the positioning hole; and the length L of the reinforcing sheet is greater than the length of the positioning hole.

[0013] Preferably, the positioning hole is a waist-shaped hole, and the shape of the latch is compatible with the positioning hole.

[0014] Preferably, the hot expansion mold also includes a lower template and an upper cone; a plurality of T-slots are evenly distributed on the lower template, and the plurality of T-slots are distributed in a star-shaped pattern; a guide block is slidably installed in each T-slot; and the guide block is connected to the expansion block by screws; the inner side surface of the expansion block is a conical surface; the upper cone includes an inverted cone portion; when the mold is closed, the outer peripheral surface of the inverted cone portion cooperates with the conical surface of the expansion block and pushes the expansion block to move radially outward.

[0015] Preferably, a first countersunk hole is provided at the center position of the top surface of the lower template, and the side wall of the first countersunk hole is connected to the T-slot; a limit block is placed in the first countersunk hole, and the limit block is used to form a blocking limit for the inner end of the guide block.

[0016] Preferably, the hot expansion mold also includes a limiting ring, which is provided with a center through hole. When the mold is closed, the inverted cone portion of the upper cone passes through the center through hole of the limiting ring; a second countersunk hole is provided on the bottom surface of the limiting ring; a limiting boss is provided on the top surface of the expansion block; the limiting ring is buckled on the top of all the expansion blocks, and the limiting boss of the expansion block extends into the second countersunk hole of the limiting ring; the inner hole surface of the second countersunk hole is used to form a blocking limit for the limiting boss; the upper cone also includes a plate body portion integrally formed on the upper end of the inverted cone portion; when the mold is closed, the lower end surface of the plate body portion is pressed against the top surface of the limiting ring.

[0017] Preferably, a latch hole is provided on the outer surface of the expansion block near the bottom end; the latch is slidably matched with the latch hole.

[0018] Preferably, in step S3, after the conical tube blank is sleeved on the hot expansion mold, the conical tube blank and the hot expansion mold are put into a hot forming device together to be heated to a set temperature in the furnace and then hot expansion is performed.

[0019] Preferably, in the step S1, when laser cutting is performed, the arcs of the large and small ends of the fan-shaped flat plate are extended in the radial direction with a margin, so that the large and small ends of the conical tube blank obtained in the step S2 are offset by 30 mm along the axial direction relative to the large and small ends of the titanium alloy cylinder; in the step S2, two pieces of fan-shaped flat plates are rounded and then welded to form a conical tube blank.

[0020] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0021] (1) Compared with the prior art, the method provided by the present invention avoids the wrinkle problem when the parts are formed in half, does not require manual knocking and repairing of forming wrinkles, reduces the on-site processing intensity, and reduces two hot forming operations to one hot forming operation, shortens the parts processing cycle, improves the parts processing efficiency, and improves the parts surface quality.

[0022] (2) In the present invention, a plurality of positioning holes are laser cut into the fan-shaped flat sheet material, and after the fan-shaped flat sheet material is rolled and welded into a conical tube blank, the conical tube blank is sleeved on the expansion block of the hot expansion mold, and the latch passes through the positioning holes and is plugged into the expansion block. The latch is used to prevent the parts from moving upward during the expansion process, which plays a good positioning role for the parts and further avoids the generation of wrinkles.

[0023] (3) In the present invention, a reinforcing plate is welded on the conical tube blank, and the reinforcing plate is welded at a position below the positioning hole. The length L of the reinforcing plate is greater than the length of the positioning hole. The reinforcing plate plays a reinforcing role, effectively preventing the lower side of the positioning hole from being pulled apart during thermal expansion of the part, thereby further ensuring the reliability of positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0025] Figure 1 This is a schematic diagram of the titanium alloy cylinder structure of the II section of the outer wall of an aircraft engine;

[0026] Figure 2 It is a three-dimensional structural diagram of the titanium alloy cylinder of the II section of the outer wall of the aircraft engine;

[0027] Figure 3 A top view of the heat expansion die of the present invention;

[0028] Figure 4 for Figure 3Middle AA section view;

[0029] Figure 5 A top view of the lower mold plate in the thermal expansion mold of the present invention;

[0030] Figure 6 for Figure 5 Middle BB section view;

[0031] Figure 7 for Figure 5 Middle CC section view;

[0032] Figure 8 A top view of a guide block in a heat expansion die of the present invention;

[0033] Fig. 9 for Figure 8 Middle DD section view;

[0034] Fig.10 for Figure 8 Middle EE section view;

[0035] Fig.11 It is a schematic diagram of the distribution of expansion blocks in the thermal expansion die of the present invention;

[0036] Fig.12 for Fig.11 Middle A-direction view;

[0037] Fig.13 for Fig.11 Middle FF section view;

[0038] Fig.14 for Fig.13 Middle B view;

[0039] Fig.15 is a cross-sectional view of an upper cone in a heat expansion die of the present invention;

[0040] Fig.16 A top view of a latch in a heat expansion die in the present invention;

[0041] Fig.17 It is an end view of the latch in the heat expansion die of the present invention;

[0042] Fig.18 It is a cross-sectional view of a limiting ring in a heat expansion die of the present invention;

[0043] Fig.19 It is a cross-sectional view of a limit block in the heat expansion die of the present invention;

[0044] Fig. 20 It is a schematic diagram of the structure of the fan-shaped flat plate material in the present invention;

[0045] Fig.21It is a schematic structural diagram of the conical tube blank in the present invention.

[0046] Explanation of the accompanying numbers: 1. Lower template; 1a. T-slot; 1b. First countersunk hole; 2. Guide block; 3. Limit block; 4. Lifting bolt; 5. Expansion block; 5a. Conical surface; 5b. Limit boss; 5c. Pin hole; 6. Limit ring; 6a. Center through hole; 6b. Second countersunk hole; 7. Upper cone; 7a. Inverted cone; 7b. Plate body; 8. Pin; 9. Lifting shaft; 10. Screw; 100. Fan-shaped flat plate; 101. Positioning hole; 200. Conical tube blank; 201. Reinforcement sheet. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0049] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0050] Combination Figure 1 , Figure 2 The figure shows the schematic diagram of the titanium alloy cylinder structure of the second section of the outer wall of the aircraft engine. The material grade of the titanium alloy cylinder is TA15, and the material thickness is t=1mm. The small end of the part is a conical surface with an outer diameter of φD2 at the mouth; the large end is a cylindrical surface with an outer diameter of φD1. The conical surface and the cylindrical surface are connected through a spherical surface, and after the connection, the central axis of the conical surface forms an angle α1 with the center of the cylindrical surface. The top surface of the small end of the titanium alloy cylinder is inclined, with a height of H1 on the short side and a height of H3 on the high side. Two longitudinal welds are allowed on the titanium alloy cylinder.

[0051] As shown in the accompanying drawings, a method for processing a spherical transition titanium alloy cylinder includes the following steps:

[0052] S1. Laser cutting: using a plate to perform laser cutting to obtain a fan-shaped flat plate 100;

[0053] S2, rolling and welding: rolling and welding the sector-shaped flat sheet 100 to obtain a tapered tube blank 200;

[0054] S3, thermal expansion: the conical tube blank 200 is placed on a thermal expansion die for thermal expansion;

[0055] S4, laser cutting: laser cutting of the large and small ends of the parts obtained after thermal expansion;

[0056] S5. Pickling: Pickle the parts obtained after laser cutting to remove the oxide scale on the surface of the parts.

[0057] In this embodiment, in step S1, a plurality of positioning holes 101 are laser cut on the fan-shaped flat sheet 100, and the positioning holes 101 are arranged near the arc edge of the large end of the fan-shaped flat sheet 100; the hot expansion mold comprises a plurality of annularly evenly distributed expansion blocks 5, and a latch 8 is inserted on the expansion block 5; in step S3, after the conical tube blank 200 is sleeved on the expansion block 5 of the hot expansion mold, the latch 8 is passed through the positioning holes 101 and then inserted on the expansion block 5. The latch 8 is used to prevent the parts from moving upward during the expansion process, which plays a good positioning role for the parts and further avoids the generation of wrinkles.

[0058] Combination Fig.21 As shown, in step S2, a reinforcing sheet 201 is welded on the tapered tube blank 200, and the reinforcing sheet 201 is welded at a position below the positioning hole 101; the length L of the reinforcing sheet 201 is greater than the length of the positioning hole 101. The reinforcing sheet 201 plays a reinforcing role, effectively preventing the lower part of the positioning hole from being broken during thermal expansion of the part, and further ensuring the reliability of positioning.

[0059] Combination Fig.16 , Fig.17 as well as Fig.21 As shown, the positioning hole 101 is a waist-shaped hole, and the shape of the latch 8 is adapted to the positioning hole 101. The purpose of setting the positioning hole 101 as a waist-shaped hole is to increase the contact area with the latch 8 and further prevent the lower part of the positioning hole from being broken during thermal expansion of the part.

[0060] Combination Figures 3 to 19As shown, the hot expansion mold also includes a lower template 1 and an upper cone 7; a plurality of T-slots 1a are evenly distributed on the lower template 1, and the plurality of T-slots 1a are distributed in a star-shaped manner; a guide block 2 is slidably installed in each T-slot 1a; and the guide block 2 is connected to the expansion block 5 by a screw 10; the inner side surface of the expansion block 5 is a conical surface 5a; the upper cone 7 includes an inverted cone 7a; when the mold is closed, the outer peripheral surface of the inverted cone 7a cooperates with the conical surface 5a of the expansion block 5, and pushes the expansion block 5 to move radially outward.

[0061] By adopting the above-mentioned hot expansion mold, in the step S3, after the conical tube blank 200 is sleeved on the hot expansion mold, the conical tube blank 200 and the hot expansion mold are put into the hot forming equipment together to be heated to the set temperature with the furnace and then hot expansion is performed. Specifically, the hot expansion mold is placed on the table of the hot forming equipment, and after the conical tube blank 200 and the hot expansion mold are heated, the pressing plate of the hot forming equipment is pressed down, so that the upper cone 7 moves downward, and pushes the expansion block 5 to move radially outward for expansion.

[0062] Combination Figure 4 , Figure 5 and Fig.19 As shown, a first countersunk hole 1b is provided at the center of the top surface of the lower template 1, and the side wall of the first countersunk hole 1b is connected to the T-slot 1a; a limit block 3 is placed in the first countersunk hole 1b, and the limit block 3 is used to form a blocking limit for the inner end of the guide block 2. When the conical tube blank 200 is assembled to the hot expansion mold, the expansion block 5 needs to be moved radially inward. When the inner end of the guide block 2 abuts against the outer cylindrical surface of the limit block 3, it means that the expansion block 5 moves inward to the right position, ensuring that all the expansion blocks 5 are on the same circumference in the initial state.

[0063] Combination Figure 4 , Figure 5 and Fig.18 As shown, the hot expansion mold also includes a limit ring 6, which is provided with a central through hole 6a. When the mold is closed, the inverted cone 7a of the upper cone 7 passes through the central through hole 6a of the limit ring 6; a second countersunk hole 6b is provided on the bottom surface of the limit ring 6; a limit boss 5b is provided on the top surface of the expansion block 5; the limit ring 6 is buckled on the top of all the expansion blocks 5, and the limit boss 5b of the expansion block 5 extends into the second countersunk hole 6b of the limit ring 6; the inner hole surface of the second countersunk hole 6b is used to form a blocking limit for the limit boss 5b; the upper cone 7 also includes a plate body 7b integrally formed on the upper end of the inverted cone 7a; when the mold is closed, the lower end surface of the plate body 7b is pressed against the top surface of the limit ring 6. When the upper cone 7 descends to the limit position, the limit boss 5b abuts against the inner hole surface of the second countersunk hole 6b, which can prevent the expansion block 5 from sliding and falling during the processing.

[0064] In order to facilitate the lifting of the upper cone 7, all the lifting bolts 4 are evenly distributed on the outer peripheral surface of the plate body 7b. In addition, in order to facilitate the lifting of the entire mold, a plurality of lifting shafts 9 are installed on the outer peripheral surface of the lower mold plate 1.

[0065] Combination Fig.12 As shown, a latch hole 5c is provided on the outer surface of the expansion block 5 near the bottom end; in order to facilitate the insertion and removal of the latch 8, the latch 8 is slidably matched with the latch hole 5c.

[0066] Combination Figure 1 , Fig.21 As shown, in the step S1, when laser cutting is performed, the arcs of the large and small ends of the fan-shaped flat plate 100 are extended along the radial direction with a margin, so that the large and small ends of the conical tube blank 200 obtained in step S2 are offset by 30 mm along the axial direction relative to the large and small ends of the titanium alloy cylinder, that is, the maximum height of the titanium alloy cylinder is H3, the small end of the conical tube blank 200 extends upward by 30 mm on the basis of H3 as a margin, and the large end of the conical tube blank 200 extends downward by 30 mm on the basis of H3 as a margin, so the height H of the conical tube blank 200 is at least 60 mm + H3.

[0067] In step S2, two fan-shaped flat sheets 100 are rounded and welded to form a conical tube blank 200, which is intended to facilitate blanking and reduce the length of the fan-shaped flat sheet 100. If a fan-shaped flat sheet is welded to obtain the conical tube blank 200, the required fan-shaped flat sheet 100 is too long and difficult to blank.

[0068] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for processing a spherical transition titanium alloy cylinder, characterized in that: The following steps are involved: S1, laser cutting: using a plate to perform laser cutting to obtain a fan-shaped flat plate (100); S2, rolling and welding: rolling and welding the sector-shaped flat plate (100) to obtain a tapered tube blank (200); S3, thermal expansion: putting the conical tube blank (200) on a thermal expansion die for thermal expansion; S4, laser cutting: laser cutting of the large and small ends of the parts obtained after thermal expansion; S5. Pickling: Pickle the parts obtained after laser cutting to remove the oxide scale on the surface of the parts.

2. A method for processing a spherical transition titanium alloy cylinder as claimed in claim 1, characterized in that: In the step S1, a plurality of positioning holes (101) are cut by laser in the fan-shaped flat plate (100), and the positioning holes (101) are arranged near the arc edge of the large end of the fan-shaped flat plate (100); The thermal expansion die comprises a plurality of expansion blocks (5) uniformly distributed in an annular shape, and a latch (8) is inserted into the expansion block (5); in the step S3, after the conical tube blank (200) is sleeved on the expansion block (5) of the thermal expansion die, the latch (8) is passed through the positioning hole (101) and then plugged into the expansion block (5).

3. A method for processing a spherical transition titanium alloy cylinder as claimed in claim 2, characterized in that: In the step S2, a reinforcing sheet (201) is welded on the obtained conical tube blank (200), and the reinforcing sheet (201) is welded at a position below the positioning hole (101); the length L of the reinforcing sheet (201) is greater than the length of the positioning hole (101).

4. A method for processing a spherical transition titanium alloy cylinder as claimed in claim 2, characterized in that: The positioning hole (101) is a waist-shaped hole, and the shape of the latch (8) is adapted to the positioning hole (101).

5. A method for processing a spherical transition titanium alloy cylinder as claimed in claim 2, characterized in that: The thermal expansion die also includes a lower template (1) and an upper cone (7); a plurality of T-slots (1a) are evenly distributed on the lower template (1), and the plurality of T-slots (1a) are distributed in a star-shaped manner; a guide block (2) is slidably installed in each T-slot (1a); and the guide block (2) is connected to the expansion block (5) by means of a screw (10); the inner side profile of the expansion block (5) is a conical surface (5a); and the upper cone (7) includes an inverted cone portion (7a); When the mold is closed, the outer peripheral surface of the inverted cone (7a) matches the conical surface (5a) of the expansion block (5) and pushes the expansion block (5) to move radially outward.

6. A method for processing a spherical transition titanium alloy cylinder as claimed in claim 5, characterized in that: A first countersunk hole (1b) is provided at the center position of the top surface of the lower template (1), and the side wall of the first countersunk hole (1b) is connected to the T-shaped groove (1a); a limit block (3) is placed in the first countersunk hole (1b), and the limit block (3) is used to form a blocking limit for the inner end of the guide block (2).

7. A method for processing a spherical transition titanium alloy cylinder as claimed in claim 5, characterized in that: The thermal expansion mold further comprises a limiting ring (6), the limiting ring (6) is provided with a central through hole (6a), when the mold is closed, the inverted cone (7a) of the upper cone (7) passes through the central through hole (6a) of the limiting ring (6); a second countersunk hole (6b) is provided on the bottom surface of the limiting ring (6); a limiting boss (5b) is provided on the top surface of the expansion block (5); the limiting ring (6) is buckled on the top of all the expansion blocks (5), and the limiting boss (5b) of the expansion block (5) extends into the second countersunk hole (6b) of the limiting ring (6); the inner hole surface of the second countersunk hole (6b) is used to form a blocking limit for the limiting boss (5b); The upper cone (7) also includes a plate body (7b) integrally formed on the upper end of the inverted cone (7a); when the mold is closed, the lower end surface of the plate body (7b) is pressed tightly against the top surface of the limit ring (6).

8. A method for processing a spherical transition titanium alloy cylinder as claimed in claim 2, characterized in that: A latch hole (5c) is provided on the outer profile of the expansion block (5) near the bottom end; the latch (8) is slidably matched with the latch hole (5c).

9. The method for processing a spherical transition titanium alloy cylinder according to claim 1, characterized in that: In step S3, after the conical tube blank (200) is sleeved on the heat expansion mold, the conical tube blank (200) and the heat expansion mold are placed together in a hot forming device to be heated to a set temperature in the furnace and then heat expanded.

10. The method for processing a spherical transition titanium alloy cylinder according to claim 1, characterized in that: In the step S1, when laser cutting is performed, the arcs of the large end and the small end of the fan-shaped flat plate (100) are extended along the radial direction with a margin, so that the large end and the small end of the conical tube blank (200) obtained in the step S2 are offset by 30 mm along the axial direction relative to the large end and the small end of the titanium alloy tube body; in the step S2, two fan-shaped flat plates (100) are rounded and then welded to form a conical tube blank (200).

Images