Die for stamping forming of gas turbine stator blade guide pipe and its stamping forming method

Abstract

The present invention relates to the technical field of metal sheet processing, in particular to a die for stamping and forming a guide pipe of a gas turbine stationary blade and a stamping and forming method thereof. The die for stamping and forming a guide pipe of a gas turbine stationary blade and the stamping and forming method thereof according to the present invention can complete the forming of the important profile of the guide pipe through one positioning, reduce the error problem caused by repeated positioning during the forming process of the guide pipe, greatly improve the precision of the prepared guide pipe, and the overall contour error is within 0.10 mm; the forming die, through the side push rod, combined with the design of the detachable insert block, the blade concave surface forming die and the blade convex surface forming die, avoids the negative angle problem that cannot be overcome in ordinary stamping when forming a torsional curved surface, and simultaneously completes multiple actions such as leading edge bending and blade concave surface (concave surface) and blade convex surface (convex surface) in one die; the flanging die can be used not only for the forming of the guide pipe but also as a subsequent welding jig, realizing the diversification of functions.

Description

Technical Field

[0001] The present invention relates to the technical field of metal sheet processing, and in particular to a die for stamping and forming a guide pipe of a stationary blade of a gas turbine and a stamping and forming method thereof. Background Art

[0002] A gas turbine is an advanced and complex power mechanical equipment, and is one of the important symbols to measure a country's scientific and technological strength and comprehensive national strength. The blade is the core component for realizing the "work - function" conversion in the gas turbine, and its safety and reliability are crucial for the normal operation of the gas turbine. Since the blade is in a high - temperature and high - pressure working environment, it is necessary to reduce the internal temperature field of the blade in a proper way to improve its service life.

[0003] The stationary blade of the gas turbine turbine is of a hollow structure, and a guide pipe (also called a blade bushing) is arranged in the inner cavity. Cooling air is introduced into the guide pipe, and a large number of small holes on the guide pipe wall surface guide the cold air to impact the inner wall surface of the blade, thereby reducing the blade temperature. To ensure excellent cooling effect during the cold air impact process, an accurate distance must be maintained between the guide pipe and the inner wall surface of the blade. Since the blade itself has a high - precision complex inner cavity, it is required that the guide pipe also has a high - precision complex surface, which is difficult to manufacture.

[0004] The shape of the guide pipe changes with the shape of the stationary blade. It is a kind of thin - walled hollow structural part, the surface is an irregular torsional curved surface, and the cross - section is non - uniform in the pipe length direction, as Figure 1-2 shown. The main characteristic surfaces of this kind of part are the suction surface, the leading edge, the pressure surface, and the intermediate partition surface. Among them, the suction surface is concave, and the curvatures at various positions on the suction surface and the pressure surface are different.

[0005] In the field of manufacturing the guide pipe of the gas turbine stationary blade, plastic forming technologies such as the internal high - pressure forming technology and the stamping forming technology are most widely used. For example, the experimental device with the publication number CN102310135A is an internal high - pressure device for forming guide pipe - type parts, which can be used to form guide pipe - type parts with complex cross - sections. However, this technology requires a strict sealing device, the parts are severely thinned, it is difficult to form small round corners, and the cost of custom - made equipment for small - batch parts is high. The experimental device with the publication number CN103586634A gives a die for stamping and forming the gas turbine guide pipe. This method and the experimental device simplify the process flow of guide pipe forming, improve the forming accuracy and material utilization rate. However, this method can only be used for forming guide pipes with relatively simple surface features such as no kinking on the pipe body of the guide pipe, and it is difficult to apply to the forming of guide pipes with complex surfaces. Summary of the Invention

[0006] In order to solve the problems of poor accuracy, high production cost, and complex process flow of the guide pipe of the static blade of a gas turbine prepared by the prior art, the purpose of the present invention is to provide a die for stamping and forming the guide pipe of the static blade of a gas turbine and its stamping and forming method; based on this, the stamping and forming process of the guide pipe can be carried out.

[0007] In the prior art, the preparation of the guide pipe usually has many forming steps, repeated positioning of important profiles, and poor accuracy of the formed parts. In the present invention, the forming of the important profiles of the guide pipe is completed through one positioning, the die assembly is simple, the forming process is convenient and efficient, and the produced parts have high accuracy.

[0008] The purpose of the present invention can be achieved through the following technical solutions:

[0009] The first purpose of the present invention is to provide a die for stamping and forming the guide pipe of the static blade of a gas turbine, including an independently arranged stamping die and a flanging die.

[0010] The stamping die includes an upper template, a lower template, guide pillars and sleeves, push rods, limit columns, a forming upper die, a forming lower die, a support structure, and a forming structure. The lower template is arranged parallel and spaced from the upper template. The forming upper die is arranged on the lower surface of the upper template, and the forming lower die is arranged on the upper surface of the lower template. The upper surface of the forming lower die is connected to the support structure or the forming structure. A position for accommodating the sheet metal is arranged in the middle of the forming structure or the support structure. The guide pillars and sleeves and the limit columns are sequentially arranged on the side of the forming lower die along the central axis of the lower template. The push rods are parallel to the lower template and sequentially pass through the limit columns and the guide pillars and sleeves from the outside to the inside.

[0011] The flanging die is a detachable die with a small die size and high die profile accuracy. Each component is designed according to the inner and outer surfaces of the guide pipe, including a blade concave surface flanging die, a blade convex surface flanging die, a blade concave surface fixture, a blade convex surface fixture, and a mandrel. The blade concave surface flanging die is fitted and connected with the blade concave surface fixture, and the blade convex surface flanging die is fitted and connected with the blade convex surface fixture. The blade concave surface flanging die is movably connected to the blade convex surface flanging die, and the blade concave surface fixture is movably connected to the blade convex surface fixture. A space for accommodating the mandrel is arranged at the connection position of the blade convex surface flanging die, the blade convex surface fixture, the blade concave surface flanging die, and the blade concave surface fixture.

[0012] The stamping die is used to form the blade concave surface, leading edge, and blade convex surface of the guide pipe, and support and position the guide pipe sheet metal.

[0013] The flanging die is used for blade concave surface fillet flanging and blade convex surface fillet flanging; and serves as a welding jig for the guide pipe to clamp and align the distorted guide pipe.

[0014] In an embodiment of the present invention, when the upper surface of the forming upper die is connected to the supporting structure, the central axes of the upper template, the lower template, the forming upper die, the forming lower die and the supporting structure are the same;

[0015] When the upper surface of the forming upper die is connected to the forming structure, the central axes of the upper template, the lower template, the forming upper die, the forming lower die and the forming structure are the same.

[0016] In an embodiment of the present invention, a positioning pin is arranged on one side of the supporting structure close to the forming upper die to position the sheet metal by restricting the degree of freedom of the "waist line" of the sheet metal, and also to prevent the forming upper die from contacting the forming lower die and causing damage to the die; the supporting structure is bolted to the forming lower die to play a supporting role.

[0017] In an embodiment of the present invention, the forming structure includes a back forming die for forming the back surface of the sheet metal blade and a front forming die for forming the front surface of the sheet metal blade. The front forming die and the back forming die are respectively connected to the forming lower die by a first dovetail groove and a second dovetail groove, and are arranged along the central axis of the forming lower die, and a position for accommodating the sheet metal is provided in the middle.

[0018] In an embodiment of the present invention, the back forming die and the front forming die are connected to the forming lower die through dovetail grooves, restricting the degrees of freedom of the back forming die and the front forming die in the up-down and front-back four directions, and enabling lateral feeding.

[0019] In an embodiment of the present invention, a back forming die baffle is arranged on one side of the back forming die away from the front forming die, and the back forming die is bolted to the back forming die baffle;

[0020] A front forming die baffle is arranged on one side of the front forming die away from the back forming die, and the front forming die is bolted to the front forming die baffle;

[0021] The back forming die baffle and the front forming die baffle serve as a limiting device for lateral feeding.

[0022] In an embodiment of the present invention, the push rod is used to provide a lateral feeding force; the guide pillar and guide sleeve are used to provide a positioning reference; the mold surfaces of the forming upper die, the forming lower die, the back forming die and the front forming die are all obtained through compensation.

[0023] In an embodiment of the present invention, a third dovetail groove is arranged on the front clamp, and the front clamp is connected to the front flanging die through the third dovetail groove;

[0024] A fourth dovetail groove is arranged on the back clamp, and the back clamp is connected to the back forming die through the fourth dovetail groove.

[0025] In an embodiment of the present invention, the fitting precision tolerance between the back - blade fixture and the back - blade forming die is less than 0.02 mm;

[0026] The fitting precision tolerance between the front - blade fixture and the front - blade forming die is less than 0.02 mm.

[0027] In an embodiment of the present invention, the front - blade flanging die and the back - blade flanging die are connected by bolts.

[0028] The front - blade fixture and the back - blade fixture are connected by bolts.

[0029] In an embodiment of the present invention, the front - blade fixture, the back - blade fixture, the front - blade flanging die and the back - blade flanging die are positioned by pins and powered by bolts.

[0030] In an embodiment of the present invention, a baffle for limiting is arranged on one side of the front - blade fixture and the back - blade fixture along the length direction.

[0031] The second object of the present invention is to provide a stamping method for a die used for stamping and forming a guide pipe of a stationary blade of a gas turbine, comprising the following steps:

[0032] (S1) Place the sheet metal at the position in the support structure for accommodating the sheet metal, and drive the upper template and the forming lower die downward by a press, so that after the forming upper die contacts the sheet metal, it drives the sheet metal to complete bending (since the sheet metal itself is a twisted curved - surface part, the opening angle of the forming lower die is about 40° to avoid stamping negative angles and leave a margin for die compensation), and a pre - treated sheet metal is obtained;

[0033] (S2) Disassemble the support structure and install the forming structure, then place the pre - treated sheet metal obtained in step (S1) at the position in the forming structure for accommodating the sheet metal, provide a lateral feeding force by a push rod, the forming structure drives the pre - treated sheet metal to move laterally (the front - blade forming die, the back - blade forming die and the forming lower die are constrained in their lateral movement by dovetail grooves), and use the front - blade forming baffle and the back - blade forming die baffle for limiting to realize the forming of the front - blade surface, the leading edge and the back - blade surface of the pre - treated sheet metal, and a pre - formed guide pipe is obtained;

[0034] (S3) Place the preformed guide vane tube obtained in step (S2) outside the mandrel in the flanging die. Use the pin to provide a positioning reference. Use the front flanging die, rear flanging die, front fixture, and rear fixture to clamp the preformed guide vane tube and the mandrel with the pre-tightening force of bolts. After providing a certain pre-tightening force, place the baffle to complete the positioning of the preformed guide vane tube in the length direction. The front flanging die and the rear flanging die are constrained by the dovetail grooves to the front fixture and the rear fixture respectively. After the constraint, the front flanging die and the rear flanging die can only move horizontally, and complete the front fillet flanging and rear fillet flanging of the preformed guide vane tube to obtain the formed guide vane tube.

[0035] In the present invention, the two sets of dies are convenient to operate, have high die surface accuracy, precise cooperation, and few human interference factors. At the same time, the flanging die has various functions and is easy to disassemble and assemble, and can be flexibly used for the forming process of the guide vane tube of the gas turbine stationary blade.

[0036] The working principle of the present invention is specifically as follows:

[0037] The stamping forming method of the die for stamping and forming the guide vane tube of the gas turbine stationary blade in the present invention effectively distributes the forming surface of the guide vane tube, realizes the effective division of the concave front surface of the guide vane tube, and hands over the leading edge and part of the rear surface to the upper forming die and the lower forming die to complete the forming, and the remaining rear surface and front surface are handed over to the rear forming die and the front forming die to complete the forming; by adjusting the reference plane, the die opening is about 40°, avoiding the stamping negative angle and leaving a large safety margin for springback compensation.

[0038] In the present invention, the load of the forming die mainly comes from the servo press, and the steps of bending the sheet metal, forming the front surface and the rear surface of the guide vane tube, and disassembling the sheet metal can be completed by the downward pressure, static state, and reset of the servo press; the load of the flanging die mainly comes from the pre-tightening force of the bolts, and the final flanging forming is completed through the pre-tightening force.

[0039] In the forming die, a support structure is formed by two inserts arranged on the upper surface of the lower forming die. After the upper forming die descends and closes, the sheet metal is closely attached to the lower forming die. Further, in the forming die, a forming structure is formed by the front forming die and the rear forming die arranged on the upper surface of the lower forming die. Among them, the front forming die and the rear forming die are connected to the lower forming die through dovetail grooves and are arranged on both sides of the upper forming die. The front forming die faces the front surface of the upper forming die, and the rear forming die faces the rear surface of the upper forming die.

[0040] The flanging die consists of five parts. The front blade surface fixture and the back blade surface fixture face the front blade surface and the back blade surface of the preformed draft tube and the mandrel after forming by the forming die. At this time, the mandrel is clamped inside the front blade surface fixture, the back blade surface fixture and the preformed draft tube. The front blade surface flanging die and the back blade surface flanging die are respectively placed in the dovetail grooves of the front blade surface fixture and the back blade surface fixture. After clamping, the pressing plate makes the sheet material closely adhere to the mandrel to complete all flanging and forming.

[0041] Both the forming die and the flanging die include dovetail groove fits. In the forming die, the front blade surface forming die, the back blade surface forming die and the lower forming die are constrained by the dovetail grooves so that the front blade surface forming die and the back blade surface forming die can only move horizontally; in the flanging die, the front blade surface flanging die and the back blade surface flanging die are constrained by the dovetail grooves with the front blade surface fixture and the back blade surface fixture, so that the front blade surface forming die and the back blade surface forming die can only move horizontally by tightening bolts. Among them, the dovetail groove fit has a relatively high precision, and the tolerance is 0.02 mm.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The die for stamping and forming the draft tube of the gas turbine stationary blade and its stamping and forming method of the present invention can realize the production and manufacturing of the draft tube of the gas turbine stationary blade, is simple to operate, and can be used for mass production.

[0044] (2) The die for stamping and forming the draft tube of the gas turbine stationary blade and its stamping and forming method of the present invention have a short process flow, simple preparation procedures, a finished product rate of more than 90%, effectively improve the material utilization rate, and save production costs.

[0045] (3) The die for stamping and forming the draft tube of the gas turbine stationary blade and its stamping and forming method of the present invention can complete the forming of the important profile of the draft tube through one-time positioning, reduce the error problem caused by repeated positioning in the forming process of the draft tube, greatly improve the precision of the prepared draft tube, and the overall contour error is within 0.10 mm.

[0046] (4) In the stamping and forming method of the die for stamping and forming the draft tube of the gas turbine stationary blade of the present invention, the forming die uses a lateral push rod, combined with the design of a detachable insert block, a front blade surface forming die and a back blade surface forming die, to avoid the negative angle problem that cannot be overcome in ordinary stamping when forming a torsional curved surface, and completes multiple actions such as leading edge bending and front blade surface (concave surface) and back blade surface (convex surface) in one die.

[0047] (5) The flanging die in the stamping and forming method of the die for stamping and forming the draft tube of the gas turbine stationary blade of the present invention can be used as a subsequent welding jig in addition to being used for the forming of the draft tube, realizing diversified functions. Brief Description of the Drawings

[0048] Figure 1 It is a schematic structural diagram of a typical gas turbine stator blade deflector in the prior art;

[0049] Figure 2 It is a sectional view of the gas turbine stator blade deflector along the A-A section;

[0050] Figure 3 It is a schematic structural diagram of the forming die (including the support structure, without the forming structure) in the die for stamping and forming the gas turbine stator blade guide pipe of the present invention;

[0051] Figure 4 It is a schematic structural diagram of the forming die (including the forming structure, without the support structure) in the die for stamping and forming the gas turbine stator blade guide pipe of the present invention;

[0052] Figure 5 It is a schematic structural diagram of the flanging die in the die for stamping and forming the gas turbine stator blade guide pipe of the present invention;

[0053] Figure 6 It is a schematic structural diagram of the dovetail groove in the forming die;

[0054] Figure 7 It is a schematic structural diagram of the dovetail groove in the flanging die;

[0055] Reference numerals in the figure:

[0056] 1. Upper template; 2. Lower template; 3. Forming upper die; 4. Forming lower die; 5. Support structure; 6. Locating pin; 7. Forming structure; 8. Back-of-blade forming die; 9. Back-of-blade forming die baffle; 10. Face-of-blade forming die; 11. Face-of-blade forming die baffle; 12. Guide pillar and guide sleeve; 13. Limit post; 14. Push rod; 15. Back-of-blade flanging die; 16. Back-of-blade fixture; 17. Face-of-blade flanging die; 18. Face-of-blade fixture; 19. Mandrel; 20. Baffle; 21. Locating hole; 22. First dovetail groove; 23. Third dovetail groove. Detailed implementation manners

[0057] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0058] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is less than that of the second feature.

[0060] In the description of this embodiment, the orientation or positional relationships such as "upper", "lower", "left" and "right" are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0061] In the following embodiments, unless otherwise specified, the means and methods used are conventional means and methods in the art.

[0062] Embodiment 1

[0063] This embodiment provides a die for stamping and forming a gas turbine stator vane guide pipe, as Figure 3-7 shown, which includes an independently provided stamping die and a flanging die. Among them, the stamping die is used to form the suction surface, leading edge and pressure surface of the guide pipe, and support and position the guide pipe blank; the flanging die is used for fillet flanging of the suction surface and fillet flanging of the pressure surface; and it serves as a welding jig for the guide pipe to clamp and align the distorted guide pipe;

[0064] The stamping die includes an upper template 1, a lower template 2, guide pillars and sleeves 12, a push rod 14, a limit post 13, a forming upper die 3, a forming lower die 4, a support structure 5 and a forming structure 7. The lower template 2 is arranged parallel and spaced apart from the upper template 1. The forming upper die 3 is arranged on the lower surface of the upper template 1, and the forming lower die 4 is arranged on the upper surface of the lower template 2. The upper surface of the forming lower die 4 is connected to the support structure 5 or the forming structure 7. A position for accommodating the blank is provided in the middle of the forming structure 7 or the support structure 5. The guide pillars and sleeves 12 and the limit post 13 for providing a positioning reference are sequentially arranged on the side surface of the forming lower die 4 along the central axis of the lower template 2. The push rod 14 for providing a lateral feeding force is parallel to the lower template 2 and sequentially passes through the limit post 13 and the guide pillars and sleeves 12 from outside to inside;

[0065] The flanging die is a detachable die with a small size and high precision of the die surface. Each component is designed according to the inner and outer surfaces of the guide pipe, including the front flanging die 17, the rear flanging die 15, the front fixture 18, the rear fixture 16 and the mandrel 19. The front flanging die 17 is fitted and connected with the front fixture 18, and the rear flanging die 15 is fitted and connected with the rear fixture 16; the front flanging die 17 is movably connected with the rear flanging die 15, and the front fixture 18 and the rear fixture 16 are movably connected; a space for accommodating the mandrel 19 is provided at the connecting positions of the rear flanging die 15, the rear fixture 16, the front flanging die 17 and the front fixture 18.

[0066] Further, when the upper surface of the forming upper die 3 is connected to the supporting structure 5, the central axes of the upper template 1, the lower template 2, the forming upper die 3, the forming lower die 4 and the supporting structure 5 are the same; when the upper surface of the forming upper die 3 is connected to the forming structure 7, the central axes of the upper template 1, the lower template 2, the forming upper die 3, the forming lower die 4 and the forming structure 7 are the same.

[0067] A positioning pin 6 is provided on one side of the supporting structure 5 close to the forming upper die 3 to position the sheet metal by restricting the degree of freedom of the "waist line" of the sheet metal and also to prevent damage to the die caused by the contact between the forming upper die 3 and the forming lower die 4; the supporting structure 5 and the forming lower die 4 are connected by bolts to play a supporting role.

[0068] The forming structure 7 includes a rear forming die 8 for forming the rear surface of the sheet metal and a front forming die 10 for forming the front surface of the sheet metal. The front forming die 10 and the rear forming die 8 are respectively fitted and connected with the forming lower die 4 through the first dovetail groove 22 and the second dovetail groove and are arranged along the central axis of the forming lower die 4, and a position for accommodating the sheet metal is provided in the middle; the rear forming die 8 and the front forming die 10 are connected to the forming lower die 4 through the dovetail groove, restricting the degrees of freedom of the rear forming die 8 and the front forming die 10 in the up and down and front and back four directions, and lateral feeding can be realized; a rear forming die baffle 9 is provided on one side of the rear forming die 8 away from the front forming die 10, and the rear forming die 8 is bolted to the rear forming die baffle 9; a front forming die baffle 11 is provided on one side of the front forming die 10 away from the rear forming die 8, and the front forming die 10 is bolted to the front forming die baffle 11; the rear forming die baffle 9 and the front forming die baffle 11 serve as a limiting device for lateral feeding; the die surfaces of the forming upper die 3, the forming lower die 4, the rear forming die 8 and the front forming die 10 are all obtained through compensation.

[0069] The third dovetail groove 23 is provided on the leaf basin surface fixture 18, and the leaf basin surface fixture 18 is connected to the leaf basin surface flanging die 17 through the third dovetail groove 23; the fourth dovetail groove is provided on the leaf back surface fixture 16, and the leaf back surface fixture 16 is connected to the leaf back surface forming die 8 through the fourth dovetail groove; the fitting precision tolerance between the leaf back surface fixture 16 and the leaf back surface forming die 8 is less than 0.02 mm; the fitting precision tolerance between the leaf basin surface fixture 18 and the leaf basin surface forming die 10 is less than 0.02 mm; the leaf basin surface flanging die 17 and the leaf back surface flanging die 15 are connected by bolts, and the leaf basin surface fixture 18 and the leaf back surface fixture 16 are connected by bolts; positioning holes 21 are provided on the leaf basin surface flanging die 17, the leaf back surface flanging die 15, the leaf basin surface fixture 18 and the leaf back surface fixture 16, and pins are arranged in the positioning holes 21 to provide a positioning reference; baffles 20 for limiting are arranged on one side of the leaf basin surface fixture 18 and the leaf back surface fixture 16 along the length direction.

[0070] In summary, in the forming die, a support structure 5 is formed by two inserts provided on the upper surface of the forming lower die 4. After the forming upper die 3 descends and closes, the sheet material is pressed against the forming lower die 4. Further, in the forming die, a forming structure 7 is formed by the leaf basin surface forming die 10 and the leaf back surface forming die 8 provided on the upper surface of the forming lower die 4. Among them, the leaf basin surface forming die 10 and the leaf back surface forming die 8 are connected to the forming lower die 4 through dovetail grooves and are arranged on both sides of the forming upper die 3. The leaf basin surface forming die 10 faces the leaf basin surface of the forming upper die 3, and the leaf back surface forming die 8 faces the leaf back surface of the forming upper die 3.

[0071] The flanging die includes five parts. The leaf basin surface fixture 18 and the leaf back surface fixture 16 face the leaf basin surface and the leaf back surface of the preformed draft tube and the mandrel 19 after the forming die forms. At this time, the mandrel 19 is clamped inside the leaf basin surface fixture 18, the leaf back surface fixture 16 and the preformed draft tube. The leaf basin surface flanging die 17 and the leaf back surface flanging die 15 are respectively placed in the dovetail grooves of the leaf basin surface fixture 18 and the leaf back surface fixture 16. After clamping, the sheet material is pressed tightly against the mandrel 19 to complete all flanging forming.

[0072] Both the forming die and the flanging die include dovetail groove fits. In the forming die, the leaf basin surface forming die 10, the leaf back surface forming die 8 and the forming lower die 4 are constrained by dovetail grooves so that the leaf basin surface forming die 10 and the leaf back surface forming die 8 can only move horizontally; in the flanging die, the leaf basin surface flanging die 17 and the leaf back surface flanging die 15 are constrained by dovetail grooves with the leaf basin surface fixture 18 and the leaf back surface fixture 16, so that the leaf basin surface forming die 10 and the leaf back surface forming die 8 can only move horizontally by tightening bolts. Among them, the dovetail groove fit has a high precision, and the tolerance is 0.02 mm.

[0073] Embodiment 2

[0074] This embodiment provides a stamping forming method for a die used for stamping and forming a draft tube of a gas turbine stationary blade, including the following steps:

[0075] (S1) The sheet material is processed by electric discharge machining according to the pre-designed sheet material size, and the processed sheet material is placed in the support structure 5 at a position to accommodate the sheet material. The upper mold plate 1 and the forming lower mold 4 are driven downward by a press, so that the forming upper mold 3 contacts the sheet material and drives the sheet material to complete bending (because the sheet material itself is a twisted curved surface part, the opening angle of the forming lower mold 4 is about 40° to avoid negative stamping angles and leave a margin for mold compensation), thereby obtaining a pre-processed sheet material;

[0076] (S2) Disassemble the support structure 5 and install the forming structure 7, then place the pre-treated sheet obtained in step (S1) in the position of the forming structure 7 to accommodate the sheet, rotate the push rod 14 to push the blade basin surface forming mold 10 and the blade back surface forming mold 8 to move toward each other, provide a lateral feeding force, and the forming structure 7 drives the pre-treated sheet to move laterally (the blade basin surface forming mold 10, the blade back surface forming mold 8 and the forming lower mold 4 constrain the lateral movement of both through the dovetail groove), and use the blade basin surface forming baffle 20 and the blade back surface forming mold baffle 9 to limit the position, so as to realize the forming of the blade basin surface, leading edge and blade back surface of the pre-treated sheet, and then loosen the push rod 14, pull the blade basin surface forming mold 10 and the blade back surface forming mold 8 outward, lift the press, and remove the pre-formed guide tube;

[0077] (S3) The preformed guide tube obtained in step (S2) is placed on the outside of the core rod 19 in the flanging mold, and a positioning reference is provided by a pin. The preformed guide tube and the core rod 19 are clamped by the blade basin surface flanging mold 17, the blade back surface flanging mold 15, the blade basin surface clamp 18 and the blade back surface clamp 16 using the bolt preload force. After providing a certain preload force, the baffle 20 is placed to complete the length direction positioning of the preformed guide tube. The blade basin surface flanging mold 17 and the blade back surface flanging mold 15 are respectively constrained by the blade basin surface clamp 18 and the blade back surface clamp 16 through dovetail grooves. The constrained blade basin surface flanging mold 17 and the blade back surface flanging mold 15 can only achieve lateral movement. Then, the pin is inserted into the positioning hole 21 for positioning, and the blade basin surface rounded flanging and the blade back surface rounded flanging of the preformed guide tube are completed to obtain a formed guide tube.

[0078] The stamping forming method of the die used for stamping the gas turbine stator blade guide duct effectively distributes the forming surface of the guide duct, realizes the effective division of the concave blade basin surface of the guide duct, and the leading edge and part of the blade back surface are completed by the forming upper die 3 and the forming lower die 4, and the remaining blade back surface and blade basin surface are completed by the blade back surface forming die 8 and the blade basin surface forming die 10; by adjusting the reference surface, the die opening is made to be about 40°, thereby avoiding the negative stamping angle and leaving a large safety margin for springback compensation.

[0079] The load of the forming die mainly comes from the servo press. The bending of the sheet metal, the forming of the blade basin surface and the blade back surface, and the disassembly of the sheet metal can be completed through the downward pressing, static state, and reset of the servo press; the load of the flanging die mainly comes from the bolt pre-tightening force, and the final flanging forming is completed through the pre-tightening force.

[0080] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the interpretation of the present invention should be within the protection scope of the present invention.

Claims

1. A die for stamping and forming the guide pipe of a gas turbine stationary blade, characterized in that, it includes a stamping die and a flanging die that are independently arranged, the stamping die includes an upper template (1), a lower template (2), a forming upper die (3), a forming lower die (4), a support structure (5), a forming structure (7), a guide pillar and bushing (12), a limit pillar (13) and a push rod (14). The lower template (2) is arranged parallel and spaced from the upper template (1). The forming upper die (3) is arranged on the lower surface of the upper template (1). The forming lower die (4) is arranged on the upper surface of the lower template (2). The upper surface of the forming lower die (4) is connected to the support structure (5) or the forming structure (7). A position for accommodating the sheet metal is arranged in the middle of the forming structure (7) or the support structure (5). The guide pillar and bushing (12) and the limit pillar (13) are sequentially arranged on the side of the forming lower die (4) along the central axis of the lower template (2). The push rod (14) is parallel to the lower template (2) and sequentially passes through the limit pillar (13) and the guide pillar and bushing (12) from outside to inside; the flanging die includes a back flanging die for the blade (15), a back fixture for the blade (16), a front flanging die for the blade (17), a front fixture for the blade (18) and a mandrel (19). The front flanging die for the blade (17) is fitted and connected with the front fixture for the blade (18). The back flanging die for the blade (15) is fitted and connected with the back fixture for the blade (16). The front flanging die for the blade (17) is movably connected with the back flanging die for the blade (15). The front fixture for the blade (18) and the back fixture for the blade (16) are movably connected. A space for accommodating the mandrel (19) is arranged at the connection position of the back flanging die for the blade (15), the back fixture for the blade (16), the front flanging die for the blade (17) and the front fixture for the blade (18); the stamping die is used for forming the front of the guide pipe, the leading edge and the back of the blade, and supporting and positioning the guide pipe sheet metal; the flanging die is used for flanging the fillet of the front of the blade and the fillet of the back of the blade; and serves as a welding jig for the guide pipe.

2. A die for stamping and forming the guide pipe of a gas turbine stationary blade according to claim 1, characterized in that, when the upper surface of the forming upper die (3) is connected to the support structure (5), the central axes of the upper template (1), the lower template (2), the forming upper die (3), the forming lower die (4) and the support structure (5) are the same; when the upper surface of the forming upper die (3) is connected to the forming structure (7), the central axes of the upper template (1), the lower template (2), the forming upper die (3), the forming lower die (4) and the forming structure (7) are the same.

3. A die for stamping and forming the guide pipe of a gas turbine stationary blade according to claim 1, characterized in that, a positioning pin (6) for positioning the sheet metal is arranged on one side of the support structure (5) close to the forming upper die (3).

4. A die for stamping and forming the guide pipe of a gas turbine stationary blade according to claim 1, characterized in that, The forming structure (7) includes a back blade surface forming die (8) for forming the back surface of the blade blank and a front blade surface forming die (10) for forming the front surface of the blade blank. The front blade surface forming die (10) and the back blade surface forming die (8) are respectively engaged and connected to the forming lower die (4) through a first dovetail groove (22) and a second dovetail groove, and are arranged along the central axis of the forming lower die (4), with a position for accommodating the blade blank in the middle.

5. A die for stamping and forming a guide pipe of a stationary blade of a gas turbine according to claim 4, characterized in that a back blade surface forming die baffle (9) for lateral limiting is arranged on one side of the back blade surface forming die (8) away from the front blade surface forming die (10); a front blade surface forming die baffle (11) for lateral limiting is arranged on one side of the front blade surface forming die (10) away from the back blade surface forming die (8).

6. A die for stamping and forming a guide pipe of a stationary blade of a gas turbine according to claim 1, characterized in that a third dovetail groove (23) is arranged on the front blade surface fixture (18), and the front blade surface fixture (18) is connected to the front blade surface flanging die (17) through the third dovetail groove (23); a fourth dovetail groove is arranged on the back blade surface fixture (16), and the back blade surface fixture (16) is connected to the back blade surface forming die (8) through the fourth dovetail groove.

7. A die for stamping and forming a guide pipe of a stationary blade of a gas turbine according to claim 6, characterized in that the fitting precision tolerance between the back blade surface fixture (16) and the back blade surface forming die (8) is less than 0.02 mm; the fitting precision tolerance between the front blade surface fixture (18) and the front blade surface forming die (10) is less than 0.02 mm.

8. A die for stamping and forming a guide pipe of a stationary blade of a gas turbine according to claim 1, characterized in that the front blade surface flanging die (17) and the back blade surface flanging die (15) are connected by bolts, the front blade surface fixture (18) and the back blade surface fixture (16) are connected by bolts.

9. A die for stamping and forming a guide pipe of a stationary blade of a gas turbine according to claim 1, characterized in that a baffle (20) for limiting is arranged on one side of the front blade surface fixture (18) and the back blade surface fixture (16) along the length direction.

10. A stamping and forming method for a die for stamping and forming a guide pipe of a stationary blade of a gas turbine according to any one of claims 1-9, characterized in that it includes the following steps: (S1) Place the blade blank in the position for accommodating the blade blank in the support structure (5), and use the press to drive the upper template (1) and the forming lower die (4) to move downward, so that after the forming upper die (3) contacts the blade blank, it drives the blade blank to complete bending to obtain a pre-treated blade blank; (S2) Disassemble the support structure (5) and install the forming structure (7), then place the pre-treated blade blank obtained in step (S1) in the position for accommodating the blade blank in the forming structure (7), use the push rod (14) to provide a lateral feeding force, the forming structure (7) drives the pre-treated blade blank to move laterally, and use the front blade surface forming baffle (20) and the back blade surface forming die baffle (9) for limiting to realize the forming of the front blade surface, leading edge and back blade surface of the pre-treated blade blank to obtain a pre-formed guide pipe; (S3) Place the preformed guide pipe obtained in step (S2) outside the mandrel (19) in the flanging die, clamp the preformed guide pipe and the mandrel (19) using the blade surface flanging die (17), the blade back flanging die (15), the blade surface fixture (18) and the blade back fixture (16), and then use the baffle (20) for positioning to achieve the lateral movement of the preformed guide pipe, and complete the blade surface fillet flanging and the blade back fillet flanging of the preformed guide pipe to obtain the formed guide pipe.

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