Extrusion uniformity process for low pressure turbine shaft forgings

Abstract

The application discloses a low-pressure turbine shaft forging extrusion uniform process, which comprises the following steps: S1, blank forming; S2, preheating; S3, lubrication; S4, upper rod extrusion forming of the blank; S5, upper rod forming heat conduction; S6, lower rod extrusion forming of the blank; S7, lower rod forming heat conduction; S8, upsetting extrusion forming of the blank; S9, upsetting forming heat conduction; and S10, demolding. The low-pressure turbine shaft forging blank is heated once and extruded in one step, so that the low-pressure turbine shaft forging is formed once, the extrusion stress is more uniform, and the risk of shaft forging deformation and defects is reduced. The blank is heated more uniformly in the extrusion process through the heat conduction of the heat uniformizing device, the influence of uneven heating on the microstructure and mechanical properties of the blank material is reduced, the machining allowance and machining cycle are reduced, the machining efficiency is improved, material waste and production cost are reduced, and the final quality and service life of the low-pressure turbine shaft forging are improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of aero-engine shaft forgings, in particular to an extrusion uniform process for a low-pressure turbine shaft forging. BACKGROUND

[0002] In the design and manufacture of an aero-engine, a low-pressure turbine shaft forging is a core component of a transmission structure and is mainly responsible for the effective transmission of engine power and torque. In order to ensure the efficient operation and flight safety of the aero-engine, the low-pressure turbine shaft forging must have extremely high precision and reliability.

[0003] Traditional low-pressure turbine shaft forging production mainly adopts a die forging technology with multiple heating times and multiple working steps. This die forging process involves multiple heating and forging processes to gradually shape the required forging shape and size. However, multiple heating times can cause uneven temperature distribution inside the blank, thereby affecting the microstructure and mechanical properties of the material. In addition, uneven extrusion stress in the multiple forging processes can cause uneven stress distribution inside the shaft forging, increasing the risk of shaft forging deformation and defects. This further increases the machining allowance and machining cycle, which not only increases material waste and production costs, but also affects the final quality and service life of the low-pressure turbine shaft forging. SUMMARY

[0004] In order to improve the defects of uneven heating temperature of the blank and uneven extrusion stress caused by multiple heating times and multiple working steps in the low-pressure turbine shaft forging process, thereby affecting the forming efficiency and quality of the low-pressure turbine shaft forging, the application provides an extrusion uniform process for a low-pressure turbine shaft forging.

[0005] The extrusion uniform process for a low-pressure turbine shaft forging provided by the application adopts the following technical scheme:

[0006] An extrusion uniform process for a low-pressure turbine shaft forging comprises the following steps:

[0007] S1: blank forming: the blank is processed and formed;

[0008] S2: preheating: the mold is heated to a preset temperature;

[0009] S3: lubrication: the blank surface and the mold are respectively sprayed with a lubricant;

[0010] S4: upper rod extrusion forming of the blank: the blank is inserted into the lower mold, the upper mold is pressed down, and the upper mold and the lower mold cooperate to extrude the upper end of the blank, so that the upper rod of the blank is formed;

[0011] S5: heat conduction of the upper rod forming: the heat on the upper mold is conducted to the lower mold by the heat uniformizing device;

[0012] S6: lower rod extrusion forming of the blank: the upper mold is continuously pressed down, and the upper mold and the lower mold cooperate to extrude the lower end of the blank, so that the lower rod of the blank is formed.

[0013] S7: heat conduction of lower rod forming: the heat conduction device conducts heat on the lower die to the upper die;

[0014] S8: blank upsetting extrusion forming: the upper die continues to press down, and the upper die and the lower die extrude the middle position of the blank to make the blank upsetting forming;

[0015] S9: heat conduction of upsetting forming: the heat conduction device conducts heat at the middle position of the lower die to the upper die and the lower die;

[0016] S10: demolding: the upper die and the lower die are separated, and the low-pressure turbine shaft forging is taken out.

[0017] By adopting the above technical scheme, the low-pressure turbine shaft forging blank is heated once and extruded in one step, so that the low-pressure turbine shaft forging is formed once, the extrusion stress is more uniform, and the risk of shaft forging deformation and defects is reduced; and the heat conduction device conducts heat, so that the blank is heated more uniformly during extrusion in the die, and the influence of uneven heating on the microstructure and mechanical properties of the blank material is reduced; thereby the machining allowance and machining cycle are reduced, the machining efficiency is improved, the material waste and production cost are reduced, and the final quality and service life of the low-pressure turbine shaft forging are also improved.

[0018] Preferably, the upper die comprises an upper die body and a shaft hole forming rod connected with the upper die body, the upper die body is provided with an upper rod forming groove, the opening end of the upper rod forming groove is provided with an upsetting extrusion upper end face on the side, and the shaft hole forming rod is inserted into the upper rod forming groove;

[0019] The lower die comprises an extrusion sleeve, an upsetting extrusion lower protruding edge arranged at the bottom of the extrusion sleeve, and a lower rod forming die connected with the bottom of the upsetting extrusion lower protruding edge;

[0020] The step S4 further comprises the following steps:

[0021] S401: the blank is inserted into the extrusion sleeve;

[0022] S402: the upper die is inserted into the extrusion sleeve;

[0023] S403: the upper die is pressed down, the upsetting extrusion upper end face and the upsetting extrusion lower protruding edge cooperate to extrude the blank to assist the blank to be upsettingly formed in the first stage;

[0024] S404: the upper die body and the upsetting extrusion lower protruding edge cooperate to extrude the blank into the upper rod forming groove to form the upper rod of the blank;

[0025] S405: the upper die and the lower rod forming die cooperate to extrude the lower end of the blank to make the lower rod of the blank preliminarily formed.

[0026] By adopting the technical scheme, the blank is extruded by the upsetting extrusion upper end face and the upsetting extrusion lower protruding edge to realize the first-stage upsetting preliminary forming of the blank, the blank is extruded into the upper rod forming groove by the upper die body and the upsetting extrusion lower protruding edge to form the upper rod of the blank, and the lower rod of the blank is preliminarily formed by extruding the lower end of the blank by the upper die and the lower rod forming die. The upper die and the lower die are extruded to realize the upper rod forming of the blank, the preliminary forming of the lower rod of the blank, and the first-stage upsetting preliminary forming of the blank, so that the preliminary forming of the blank can be efficiently realized. The upper rod part of the blank, the upsetting part of the blank, and the lower rod part of the blank can be synchronously and uniformly extruded in the subsequent extrusion process. The die structure and the operation steps help to improve the forming efficiency and quality of the blank and ensure that the shape and size of the blank are accurately controlled in the extrusion process.

[0027] Preferably, the step S5 further includes the following steps:

[0028] S501: The upper die continues to move downward, and the upsetting extrusion upper end face and the upsetting extrusion lower protruding edge extrude the blank to assist the second-stage gradual forming of the upsetting of the blank.

[0029] S502: The shaft hole forming rod is inserted into the lower rod forming die, and the lower rod forming die extrudes the blank together with the upper die body and the shaft hole forming rod to completely form the lower rod of the blank.

[0030] S503: The upper die body and the lower rod forming die extrude the blank to supplement the forming of the upper rod of the blank.

[0031] By adopting the technical scheme, the upper die continues to move downward, the upsetting extrusion upper end face and the upsetting extrusion lower protruding edge work together to assist the second-stage gradual forming of the upsetting of the blank, which helps the blank to gradually reach the required upsetting shape and size. In step S502, the lower rod forming die, the upper die body, and the shaft hole forming rod are extruded together to completely form the lower rod of the blank, which ensures the accuracy of the shaft hole of the low-pressure turbine shaft forging and the dimensional accuracy of the lower rod part. In step S503, the upper die body and the lower rod forming die are extruded together to supplement the forming of the upper rod of the blank, so as to perfect the final shape of the upper rod of the blank. The application not only improves the overall forming quality of the blank, but also ensures the accurate cooperation and dimensional consistency of each part, thereby improving the performance and reliability of the final product. Through this phased fine forming process, material waste can be effectively reduced, production efficiency can be improved, and it can be ensured that the forgings meet strict quality standards, realizing the fine operation of the upsetting and forming of the blank.

[0032] Preferably, the step S6 further includes the following steps:

[0033] S601: The upper die continues to move downward, and the upsetting extrusion upper end surface and the upsetting extrusion lower flange cooperate to extrude the blank, so that the blank is completely formed by three-stage upsetting;

[0034] S602: The lower rod forming die cooperates with the upper die body and the shaft hole forming rod to extrude the blank, so that the lower rod of the blank is complementarily formed.

[0035] By adopting the above technical scheme, the upsetting extrusion upper end surface and the upsetting extrusion lower flange cooperate to extrude the blank, so that the blank is completely formed by three-stage upsetting, thereby ensuring the accuracy and consistency of the overall size and shape of the blank; in step S602, the lower rod forming die cooperates with the upper die body and the shaft hole forming rod to complementarily form the lower rod of the blank, which helps to improve the detailed features of the lower rod and improve the overall quality of the finished product; by three-stage complete forming of the blank and complementarily forming of the lower rod of the blank, the present application effectively realizes further fine adjustment and stability of the shape of the low-pressure turbine shaft forging, improves the accuracy and efficiency of the blank forming, and thereby ensures that the final product can meet strict performance requirements and quality standards.

[0036] Preferably, the shaft hole forming rod comprises a first extrusion rod inserted into the upper rod forming groove, a second extrusion rod connected to the end of the first extrusion rod, and an inclined slope surface provided at the connection position of the first extrusion rod and the second extrusion rod; the diameter of the first extrusion rod is greater than the diameter of the second extrusion rod; the first extrusion rod cooperates with the inclined slope surface and the second extrusion rod to form a variable cross-section through hole in the blank.

[0037] By adopting the above technical scheme, the diameter of the first extrusion rod is greater than the diameter of the second extrusion rod, and the transition between the first extrusion rod and the second extrusion rod is smoothly connected by the inclined slope surface; during forging, the cooperation of the first extrusion rod with the inclined slope surface and the second extrusion rod can effectively form a variable cross-section through hole in the blank; this structure not only ensures the uniformity and accuracy of the hole wall of the low-pressure turbine shaft forging, but also helps to reduce material waste and improve the yield, and the variable cross-section through hole design provides the required strength and functional characteristics for the final product, meeting the specific requirements of aero-engine applications.

[0038] Preferably, when the temperature of any one of the upper die, the extrusion sleeve, the upsetting extrusion lower flange, and the lower rod forming die is greater than the maximum preset temperature or less than the minimum preset temperature, the flow speed of the heat conduction medium of the heat soaking device increases to the maximum preset flow speed.

[0039] By adopting the above technical scheme, when the temperature of the upper die, the extrusion sleeve, the upsetting extrusion lower protruding edge and the lower rod forming die exceeds the maximum or minimum preset temperature threshold, the heat uniformizing device will automatically adjust the flow speed of the heat conducting medium, increase to the preset maximum flow speed, so as to quickly adjust and stabilize the temperature; this automatic adjustment mechanism ensures the uniformity and accuracy of the temperature of the die and the blank during the forging process, thereby preventing forging defects caused by excessively high or low temperature, such as deformation, cracking or uneven hardness, and improving the overall quality and production efficiency of the forgings.

[0040] Preferably, in the step S2, the die is heated to 300-500℃ in the heating furnace.

[0041] By adopting the above technical scheme, preheating the die helps to reduce thermal stress and die deformation during forging, improve the dimensional accuracy and surface quality of the forgings; and preheating the die improves the production efficiency, helps to speed up the forging cycle and reduce the waiting time for the die to reach the working temperature; heating the die to a temperature range of 300-500℃ makes the high-temperature die promote the forming process of the blank, and also helps to improve the forming quality and reduce the occurrence of process defects.

[0042] Preferably, the step S10 further comprises the following steps:

[0043] S101: the upper die and the extrusion sleeve are withdrawn;

[0044] S102: the low-pressure turbine shaft forging is taken out;

[0045] S103: the low-pressure turbine shaft forging is cooled to 100-300℃;

[0046] S104: the extrusion-formed low-pressure turbine shaft forging is subjected to straightening treatment.

[0047] By adopting the above technical scheme, in order to ensure the dimensional stability of the low-pressure turbine shaft forging and reduce residual stress, the forging is cooled to a temperature range of 100-300℃ in step S103, and the extrusion-formed low-pressure turbine shaft forging is subjected to straightening treatment in step S104 to eliminate the bending or twisting that may be generated during forging, so as to ensure that the forging meets the accurate geometric size and shape requirements; the present application not only ensures the quality and performance of the low-pressure turbine shaft forging, but also improves the precision and reliability of the low-pressure turbine shaft forging.

[0048] Preferably, in the step S4, the extrusion speed of the upper die pressing the blank is 100-120mm / s or 120-140mm / s.

[0049] By adopting the technical scheme, the upper die presses the blank at an extrusion rate of 100 mm / s to 120 mm / s or 120 mm / s to 140 mm / s. This specific rate range helps to ensure that the blank is extruded under the conditions of uniform and continuous stress, which is beneficial to the uniform deformation and filling of the blank in the die cavity, and can reduce internal defects of the material, such as cracks, folds or unevenness, which may be caused by too fast or too slow extrusion rate. In addition, the production efficiency can be improved, the continuity and stability of the forging process can be ensured, and thus the overall quality and performance of the forgings can be improved.

[0050] Preferably, the lubricant sprayed in the step S3 is a glass lubricant.

[0051] By adopting the technical scheme, the glass lubricant can effectively reduce the friction between the blank and the die, reduce the energy consumption and die wear in the forging process, and help the uniform flow and filling of the blank, and reduce surface defects caused by friction. The use of the glass lubricant also helps to improve the dimensional accuracy and surface finish of the forgings, thereby improving the quality of the final product.

[0052] In summary, the present application has at least one of the following beneficial technical effects:

[0053] 1. The low-pressure turbine shaft blank is heated once and extruded in one step, so that the low-pressure turbine shaft is formed once, the stress during extrusion is more uniform, and the risk of deformation and defects of the shaft forgings is reduced. The heat conduction device conducts heat, so that the blank is heated more uniformly during extrusion in the die, and the influence of uneven heating on the microstructure and mechanical properties of the blank material is reduced. In turn, the machining allowance and machining cycle are reduced, the machining efficiency is improved, the material waste and production cost are reduced, and the final quality and service life of the low-pressure turbine shaft forgings are improved.

[0054] 2. When the temperature of the upper die, the extrusion sleeve, the upsetting extrusion lower convex edge and the lower rod forming die exceeds the maximum or minimum preset temperature threshold, the heat conduction device automatically adjusts the flow rate of the heat conduction medium to the preset maximum flow rate to quickly adjust and stabilize the temperature. This automatic adjustment mechanism ensures the uniformity and accuracy of the temperature of the die and the blank during forging, thereby preventing defects of the forgings caused by excessively high or low temperature, such as deformation, cracks or uneven hardness, and improving the overall quality and production efficiency of the forgings. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 is a step flow diagram of an embodiment of the present application.

[0056] Figure 2 is a cross-sectional structure schematic diagram of the state of the blank inserted into the die according to an embodiment of the present application.

[0057] Figure 3 is a schematic diagram of the cross-sectional structure of the upper rod extrusion forming of the blank of the embodiment of the present application.

[0058] Figure 4 is a schematic diagram of the cross-sectional structure of the lower rod extrusion forming of the blank of the embodiment of the present application.

[0059] Figure 5 is a schematic diagram of the cross-sectional structure of the upsetting extrusion forming of the blank of the embodiment of the present application.

[0060] Explanation of reference signs:

[0061] 1, upper die body; 2, shaft hole forming rod; 21, first extrusion rod; 22, second extrusion rod; 23, inclined slope; 3, upper rod forming groove; 4, upsetting extrusion upper end face; 5, extrusion sleeve; 6, upsetting extrusion lower convex edge; 7, lower rod forming die;

[0062] 8, heat pipe; 81, upper die helical heat pipe; 82, sleeve helical heat pipe; 83, upsetting helical heat pipe; 84, lower rod helical heat pipe; 85, first telescopic heat pipe; 86, second telescopic heat pipe; 9, heat medium driving mechanism;

[0063] 10, temperature detection mechanism; 101, upper die temperature detection assembly; 102, sleeve temperature detection assembly; 103, upsetting temperature detection assembly; 104, lower rod temperature detection assembly. DETAILED DESCRIPTION

[0064] The following will be described in detail with reference to the accompanying drawings. Figures 1-5 The present application will be further described in detail.

[0065] The embodiment of the present application discloses an extrusion uniform process of low-pressure turbine shaft forgings. Referring to Figure 1 , the extrusion uniform process of low-pressure turbine shaft forgings comprises;

[0066] S1: blank forming: the blank is processed and formed;

[0067] S2: preheating: the mold is heated to a preset temperature;

[0068] S3: lubrication: the lubricant is respectively sprayed on the surface of the blank and in the mold;

[0069] S4: upper rod extrusion forming of the blank: the blank is inserted into the lower mold, the upper mold is pressed down, and the upper mold and the lower mold are matched to extrude the upper end of the blank, so that the upper rod of the blank is formed;

[0070] S5: upper rod forming heat conduction: the heat on the upper mold is conducted to the lower mold by the heat uniformizing device;

[0071] S6: lower rod extrusion forming of the blank: the upper mold is continuously pressed down, and the upper mold and the lower mold are matched to extrude the lower end of the blank, so that the lower rod of the blank is formed;

[0072] S7: Lower rod forming heat conduction: the heat on the lower die is conducted to the upper die by the heat uniformizing device;

[0073] S8: Billet upsetting extrusion forming: the upper die continues to press down, and the upper die and the lower die extrude the middle position of the billet to make the billet upsetting forming;

[0074] S9: Upsetting forming heat conduction: the heat at the middle position of the lower die is conducted to the upper die and the lower die by the heat uniformizing device;

[0075] S10: Demolding: the upper die and the lower die are separated, and the low-pressure turbine shaft forging is taken out.

[0076] The application makes the low-pressure turbine shaft forging one-time forming by one-time heating and one-step extrusion of the low-pressure turbine shaft forging billet, the stress of extrusion is more uniform, and the risk of shaft forging deformation and defects is reduced; and the heat uniformizing device is used for heat conduction, so that the billet is more uniformly heated during the extrusion in the die, and the influence of uneven heating on the microstructure and mechanical properties of the billet material is reduced; thereby the machining allowance and machining cycle are reduced, the machining efficiency is improved, the material waste and production cost are reduced, and the final quality and service life of the low-pressure turbine shaft forging are improved; further, the safe and reliable operation of the aero-engine is ensured.

[0077] In step S4 of the application, the upper die and the lower die extrude the upper end of the billet to make the upper rod of the billet form, heat is released during the extrusion, and then in step S5, the heat on the upper die is conducted to the lower die by the heat uniformizing device, so as to balance the overall temperature of the die and the billet;

[0078] In step S6, the upper die continues to press down, and the upper die and the lower die extrude the lower end of the billet to make the lower rod of the billet form, the billet continuously releases heat during the extrusion, so that the temperature increases, and then in step S7, the heat on the lower die is conducted to the upper die by the heat uniformizing device, so as to improve the uniformity of the overall temperature of the die and the billet and reduce the temperature difference;

[0079] In step S8, the upper die continues to press down, and the upper die and the lower die extrude the middle position of the billet to make the billet upsetting forming, the billet releases heat, and in step S9, the heat at the middle position of the lower die is conducted to the upper die and the lower end of the lower die by the heat uniformizing device, so as to further improve the uniformity of the overall temperature of the die and the billet during the extrusion; the influence of uneven heating on the microstructure and mechanical properties of the billet material is reduced, and the machining efficiency and machining quality of the low-pressure turbine shaft forging are improved.

[0080] Further, as Figure 2 and Figure 3As shown, the upper die includes an upper die body 1, and a shaft hole forming rod 2 connected with the upper die body 1, the upper die body 1 is provided with an upper rod forming groove 3, the opening end of the upper rod forming groove 3 is provided with a upsetting extrusion upper end face 4, and the shaft hole forming rod 2 is inserted into the upper rod forming groove 3;

[0081] The lower die includes an extrusion sleeve 5, a upsetting extrusion lower convex edge 6 provided at the bottom of the extrusion sleeve 5, and a lower rod forming die 7 connected with the bottom of the upsetting extrusion lower convex edge 6;

[0082] Step S4 further includes the following steps:

[0083] S401: inserting the blank into the extrusion sleeve 5;

[0084] S402: inserting the upper die into the extrusion sleeve 5;

[0085] S403: pressing down the upper die, the upsetting extrusion upper end face 4 and the upsetting extrusion lower convex edge 6 cooperate to extrude the blank, so as to assist the first-stage preliminary forming of the blank;

[0086] S404: the upper die body 1 and the upsetting extrusion lower convex edge 6 cooperate to extrude the blank into the upper rod forming groove 3, so as to form the upper rod of the blank;

[0087] S405: the upper die and the lower rod forming die 7 cooperate to extrude the lower end of the blank, so as to preliminarily form the lower rod of the blank.

[0088] In step S4, the upper die is pressed down, the upsetting extrusion upper end face 4 and the upsetting extrusion lower convex edge 6 cooperate to extrude the blank, so as to realize the first-stage preliminary forming of the blank, the upper die body 1 and the upsetting extrusion lower convex edge 6 cooperate to extrude the blank into the upper rod forming groove 3, so as to form the upper rod of the blank, and the upper die and the lower rod forming die 7 cooperate to extrude the lower end of the blank, so as to preliminarily form the lower rod of the blank; the upper die and the lower die cooperate to realize the upper rod forming of the blank, the preliminary forming of the lower rod of the blank, and the first-stage preliminary forming of the upsetting of the blank, so as to efficiently realize the preliminary forming of the blank; in the subsequent extrusion process, the upper rod part of the blank, the upsetting part of the blank, and the lower rod part of the blank can be synchronously and uniformly extruded, the die structure and the operation steps help to improve the forming efficiency and quality of the blank, ensure that the shape and size of the blank can be accurately controlled in the extrusion process, and ensure the consistency and accuracy of the forging quality, so as to meet the product design requirements.

[0089] Further, as shown in the figure, Figure 4 Step S5 further includes the following steps:

[0090] S501: continuing to move down the upper die, the upsetting extrusion upper end face 4 and the upsetting extrusion lower convex edge 6 cooperate to extrude the blank, so as to assist the second-stage gradual forming of the upsetting of the blank;

[0091] S502: The shaft hole forming rod 2 is inserted into the lower rod forming die 7, and the lower rod forming die 7 cooperates with the upper die body 1 and the shaft hole forming rod 2 to extrude the blank, so that the lower rod of the blank is completely formed;

[0092] S503: The upper die body 1 and the lower rod forming die 7 cooperate to extrude the blank, so that the upper rod of the blank is complementarily formed.

[0093] In step S501, the upper die continues to move downward, the upsetting extrusion upper end surface 4 and the upsetting extrusion lower convex edge 6 work together to assist the blank to be gradually formed by two-stage upsetting, which helps the blank to gradually reach the required upsetting shape and size; in step S502, the lower rod forming die 7 cooperates with the upper die body 1 and the shaft hole forming rod 2 to complete the complete forming of the lower rod of the blank, which ensures the accuracy of the shaft hole of the low-pressure turbine shaft forging and the dimensional accuracy of the lower rod part; in step S503, the upper die body 1 cooperates with the lower rod forming die 7 to complementarily form the upper rod part of the blank, so as to perfect the final shape of the upper rod part of the blank; the present application not only improves the overall forming quality of the blank, but also ensures the accurate cooperation and dimensional consistency of each part, thereby improving the performance and reliability of the final product; through this phased fine forming process, material waste can be effectively reduced, production efficiency can be improved, and forgings can meet strict quality standards, realizing fine operation of blank upsetting and forming.

[0094] Specifically, as shown in Figure 5 step S6 further includes the following steps:

[0095] S601: The upper die continues to move downward, and the upsetting extrusion upper end surface 4 and the upsetting extrusion lower convex edge 6 cooperate to extrude the blank, so that the blank is completely formed by three-stage upsetting;

[0096] S602: The lower rod forming die 7 cooperates with the upper die body 1 and the shaft hole forming rod 2 to extrude the blank, so that the lower rod of the blank is complementarily formed.

[0097] In step S601, the upper die continues to move downward, and the upsetting extrusion upper end surface 4 and the upsetting extrusion lower convex edge 6 work together to extrude the blank by three-stage upsetting, so that the blank upsetting reaches a completely formed state, ensuring the accuracy and consistency of the overall size and shape of the blank; in step S602, the lower rod forming die 7 cooperates with the upper die body 1 and the shaft hole forming rod 2 to complementarily form the lower rod part of the blank, which helps to perfect the detailed features of the lower rod and improve the overall quality of the finished product; through three-stage complete forming of the blank upsetting and complementarily forming of the lower rod of the blank, the present application effectively realizes further fine adjustment and stability of the shape of the low-pressure turbine shaft forging, improves the accuracy and efficiency of the blank forming, and thus ensures that the final product can meet strict performance requirements and quality standards.

[0098] More specifically, as shown inFigure 5 As shown, the shaft hole forming rod 2 includes a first extrusion rod 21 inserted into the upper rod forming groove 3, a second extrusion rod 22 connected to the end of the first extrusion rod 21, and an inclined slope 23 provided at the connection position of the first extrusion rod 21 and the second extrusion rod 22; the diameter of the first extrusion rod 21 is larger than the diameter of the second extrusion rod 22; the first extrusion rod 21 cooperates with the inclined slope 23 and the second extrusion rod 22 to form a variable cross-section through hole in the blank.

[0099] The diameter of the first extrusion rod 21 of the present application is larger than the diameter of the second extrusion rod 22, and the transition between the first extrusion rod 21 and the second extrusion rod 22 is smoothly connected through the inclined slope 23; during forging, the cooperation of the first extrusion rod 21 with the inclined slope 23 and the second extrusion rod 22 can effectively form a variable cross-section through hole in the blank; this structure not only ensures the uniformity and accuracy of the hole wall of the low-pressure turbine shaft forging, but also helps to reduce material waste, improve yield, and the design of the variable cross-section through hole provides the required strength and functional characteristics for the final product, meeting the specific requirements of aircraft engine applications.

[0100] In addition, as shown, Figure 3 When any of the upper die, extrusion sleeve 5, upsetting extrusion lower flange 6, and lower rod forming die 7 has a temperature greater than the maximum preset temperature or less than the minimum preset temperature, the heat conduction medium flow rate of the heat equalizing device is increased to the maximum preset flow rate.

[0101] When the temperature of the upper die, extrusion sleeve 5, upsetting extrusion lower flange 6, and lower rod forming die 7 exceeds the maximum or minimum preset temperature threshold, the heat equalizing device automatically adjusts the flow rate of the heat conduction medium to increase to the preset maximum flow rate to quickly adjust and stabilize the temperature; this automatic adjustment mechanism ensures the uniformity and accuracy of the temperature of the die and the blank during forging, thereby preventing defects such as deformation, cracking, or uneven hardness caused by excessive or insufficient temperature, and improving the overall quality and production efficiency of the forgings.

[0102] The heat equalizing device of the present application includes a heat conduction pipe 8, a flowing heat conduction medium provided in the heat conduction pipe 8, a heat conduction medium driving mechanism 9 in communication with the heat conduction pipe 8, and a temperature detection mechanism 10;

[0103] When any of the upper die, extrusion sleeve 5, upsetting extrusion lower flange 6, and lower rod forming die 7 has a temperature greater than the maximum preset temperature or less than the minimum preset temperature, the temperature detection mechanism 10 triggers the heat conduction medium driving mechanism 9 to drive the flow rate of the flowing heat conduction medium to increase to the preset maximum flow rate.

[0104] The heat conduction pipe 8 comprises an upper die helical heat conduction pipe 81 inserted into the upper die body 1, a sleeve helical heat conduction pipe 82 inserted into the side wall of the extrusion sleeve 5, a upsetting helical heat conduction pipe 83 inserted into the upsetting extrusion lower protruding edge 6, a lower stem helical heat conduction pipe 84 inserted into the lower stem forming die 7, a first telescopic heat conduction pipe 85 arranged between the upper die helical heat conduction pipe 81 and the sleeve helical heat conduction pipe 82, and a second telescopic heat conduction pipe 86 arranged between the lower stem helical heat conduction pipe 84 and the upper die helical heat conduction pipe 81.

[0105] The upper die helical heat conduction pipe 81, the first telescopic heat conduction pipe 85, the sleeve helical heat conduction pipe 82, the upsetting helical heat conduction pipe 83, the lower stem helical heat conduction pipe 84, and the second telescopic heat conduction pipe 86 are sequentially communicated.

[0106] As shown in Figure 4 The temperature detection mechanism 10 comprises an upper die temperature detection assembly 101 inserted into the upper die body 1, a sleeve temperature detection assembly 102 inserted into the side wall of the extrusion sleeve 5, a upsetting temperature detection assembly 103 inserted into the upsetting extrusion lower protruding edge 6, and a lower stem temperature detection assembly 104 inserted into the lower stem forming die 7.

[0107] Further, the temperature detection mechanism 10 is also used for detecting the temperature difference between any two of the upper die temperature detection assembly 101, the sleeve temperature detection assembly 102, the upsetting temperature detection assembly 103, and the lower stem temperature detection assembly 104. When the temperature difference between any two of the upper die temperature detection assembly 101, the sleeve temperature detection assembly 102, the upsetting temperature detection assembly 103, and the lower stem temperature detection assembly 104 is greater than a preset temperature difference value, the temperature detection mechanism 10 triggers the heat conduction medium driving mechanism 9 to drive the flow speed of the flowing heat conduction medium to increase to a maximum preset flow speed, so as to quickly adjust and stabilize the temperature, and ensure the temperature uniformity and accuracy of the die and the blank.

[0108] The heat conduction medium driving mechanism 9 is preferably a high-temperature medium pump, the flowing heat conduction medium is preferably a nano-fluid or hot oil, and the temperature detection mechanism 10 is preferably a temperature sensor.

[0109] Further, in step S2, the die is heated to 300-500°C in a heating furnace.

[0110] The present application helps to reduce thermal stress and die deformation in the forging process, improves the size accuracy and surface quality of the forgings, and improves the production efficiency by preheating the die, which helps to speed up the forging cycle and reduce the waiting time for the die to reach the working temperature. Heating the die to a temperature range of 300-500°C can promote the forming process of the blank with the high-temperature die, and also help to improve the forming quality and reduce the occurrence of process defects.

[0111] Further, step S10 further comprises the following steps:

[0112] S101: the upper die and the extrusion sleeve 5 are withdrawn;

[0113] S102: the low-pressure turbine shaft forging is taken out;

[0114] S103: the low-pressure turbine shaft forging is cooled to 100-300 DEG C;

[0115] S104: the extruded low-pressure turbine shaft forging is straightened.

[0116] In order to ensure the dimensional stability of the low-pressure turbine shaft forging and reduce residual stress, the forging is cooled to a temperature range of 100-300 DEG C in step S103, and the extruded low-pressure turbine shaft forging is straightened in step S104 to eliminate the bending or distortion that may be generated during forging, so as to ensure that the forging meets the precise geometric size and shape requirements; the application not only ensures the quality and performance of the low-pressure turbine shaft forging, but also improves the precision and reliability of the low-pressure turbine shaft forging, so that the application of the low-pressure turbine shaft forging on the aero-engine is safer and has a longer service life.

[0117] Further, the extrusion rate of the upper die in pressing the blank in step S4 is 100-120 mm / s or 120-140 mm / s.

[0118] The upper die of the application presses the blank at an extrusion rate of 100-120 mm / s or 120-140 mm / s, which helps to ensure that the blank is extruded under the condition of uniform and continuous stress, which is not only beneficial to the uniform deformation and filling of the blank in the mold cavity, but also can reduce the internal defects of the material caused by too fast or too slow extrusion rate, such as cracks, folds or unevenness; and can also improve the production efficiency, ensure the continuity and stability of the forging process, and thus improve the overall quality and performance of the forging.

[0119] Specifically, the lubricant sprayed in step S3 is a glass lubricant.

[0120] The glass lubricant has high temperature resistance and good lubricating performance, which can provide stable lubrication effect between the blank and the mold during high temperature forging; the glass lubricant can effectively reduce the friction between the blank and the mold, reduce the energy consumption and mold wear during forging, and at the same time, help the uniform flow and filling of the blank, reduce the surface defects caused by friction; the use of glass lubricant also helps to improve the dimensional accuracy and surface finish of the forging, thereby improving the quality of the final product.

[0121] The implementation principle of the extrusion uniform process of the low-pressure turbine shaft forging according to the application is as follows:

[0122] By heating the low-pressure turbine shaft forging blank once and extruding it in one step, the low-pressure turbine shaft forging is formed once, the extrusion stress is more uniform, and the risk of deformation and defects of the shaft forging is reduced; and the blank is heated more uniformly during extrusion in the mold by the heat conduction device, reducing the influence of uneven heating on the microstructure and mechanical properties of the blank material; thereby reducing the machining allowance and processing cycle, improving the processing efficiency, reducing material waste and production cost, and also improving the final quality and service life of the low-pressure turbine shaft forging; further ensuring the safe and reliable operation of the aero-engine;

[0123] When the temperature of the upper die, the extrusion sleeve 5, the upsetting extrusion lower convex edge 6, and the lower rod forming die 7 exceeds the maximum or minimum preset temperature threshold, the heat conduction device automatically adjusts the flow speed of the heat conduction medium to the preset maximum flow speed to quickly adjust and stabilize the temperature; this automatic adjustment mechanism ensures the uniformity and accuracy of the temperature of the mold and the blank during forging, thereby preventing defects such as deformation, cracking, or uneven hardness of the forging caused by excessive or insufficient temperature, and improving the overall quality and production efficiency of the forging.

[0124] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application, therefore: any equivalent changes made in terms of structure, shape, principle, etc. according to the present application should be covered within the protection scope of the present application.

Claims

1. A process for extrusion homogenization of low pressure turbine shaft forgings, characterized in that, Comprise; S1: blank forming: blank processing forming; S2: preheating: mold heating to a preset temperature; S3: lubrication: the surface of the blank and the mold are respectively sprayed with lubricant; S4: upper rod extrusion forming of the blank: the blank is inserted into the lower mold, the upper mold is pressed down, and the upper mold and the lower mold cooperate to extrude the upper end of the blank, so that the upper rod of the blank is formed; S5: upper rod forming heat conduction: the heat on the upper mold is conducted to the lower mold by the heat conduction device; S6: lower rod extrusion forming of the blank: the upper mold continues to press down, and the upper mold and the lower mold cooperate to extrude the lower end of the blank, so that the lower rod of the blank is formed; S7: lower rod forming heat conduction: the heat on the lower mold is conducted to the upper mold by the heat conduction device; S8: upset extrusion forming of the blank: the upper mold continues to press down, and the upper mold and the lower mold extrude the middle position of the blank, so that the blank is upset formed; S9: upset forming heat conduction: the heat at the middle position of the lower mold is conducted to the upper mold and the lower mold by the heat conduction device; S10: demolding: the upper mold and the lower mold are separated, and the low-pressure turbine shaft forging is taken out; The heat conduction device comprises a heat conduction pipe (8), a flowing heat conduction medium arranged in the heat conduction pipe (8), a heat conduction medium driving mechanism (9) communicated with the heat conduction pipe (8), and a temperature detection mechanism (10); When any one of the upper mold, the extrusion sleeve (5), the upset extrusion lower protrusion (6), and the lower rod forming die (7) has a temperature greater than a maximum preset temperature or less than a minimum preset temperature, the temperature detection mechanism (10) triggers the heat conduction medium driving mechanism (9) to drive the flowing speed of the flowing heat conduction medium to increase to a preset maximum flowing speed.

2. A process for extrusion homogenization of low pressure turbine shaft forgings as claimed in claim 1 wherein, The upper mold comprises an upper mold body (1) and an axial hole forming rod (2) connected with the upper mold body (1), the upper mold body (1) is provided with an upper rod forming groove (3), the opening end of the upper rod forming groove (3) is provided with an upset extrusion upper end face (4), and the axial hole forming rod (2) is inserted into the upper rod forming groove (3); The lower mold comprises an extrusion sleeve (5), an upset extrusion lower protrusion (6) arranged at the bottom of the extrusion sleeve (5), and a lower rod forming die (7) connected with the bottom of the upset extrusion lower protrusion (6); The S4 further comprises the following steps: S401: the blank is inserted into the extrusion sleeve (5); S402: the upper mold is inserted into the extrusion sleeve (5); S403: the upper mold is pressed down, the upset extrusion upper end face (4) and the upset extrusion lower protrusion (6) cooperate to extrude the blank, so as to assist the first stage of the upset forming of the blank; S404: the upper mold body (1) and the upset extrusion lower protrusion (6) cooperate to extrude the blank into the upper rod forming groove (3), so as to form the upper rod of the blank; S405: the upper mold and the lower rod forming die (7) cooperate to extrude the lower end of the blank, so that the lower rod of the blank is preliminarily formed.

3. A process of extrusion homogenization of low pressure turbine shaft forging as claimed in claim 2 wherein, The S5 further comprises the following steps: S501: the upper mold continues to move down, the upset extrusion upper end face (4) and the upset extrusion lower protrusion (6) cooperate to extrude the blank, so as to assist the second stage of the upset forming of the blank; S502: the shaft hole forming rod (2) is inserted into the lower rod forming die (7), and the lower rod forming die (7) is matched with the upper die body (1) and the shaft hole forming rod (2) to extrude the blank, so that the lower rod of the blank is completely formed; S503: the upper die body (1) and the lower rod forming die (7) are matched to extrude the blank, so that the upper rod of the blank is complementarily formed.

4. A process of extrusion homogenization of low pressure turbine shaft forging as claimed in claim 2 wherein, The S6 further comprises the following steps: S601: the upper die continues to move downward, the upsetting extrusion upper end face (4) and the upsetting extrusion lower protrusion (6) are matched to extrude the blank, so that the three-stage upsetting of the blank is completely formed; S602: the lower rod forming die (7) is matched with the upper die body (1) and the shaft hole forming rod (2) to extrude the blank, so that the lower rod of the blank is complementarily formed.

5. A process of extrusion homogenization of low pressure turbine shaft forging as claimed in claim 2 wherein, The shaft hole forming rod (2) comprises a first extrusion rod (21) inserted into the upper rod forming groove (3), a second extrusion rod (22) connected with the end of the first extrusion rod (21), and an inclined slope (23) arranged at the connection position of the first extrusion rod (21) and the second extrusion rod (22); the diameter of the first extrusion rod (21) is greater than that of the second extrusion rod (22); the first extrusion rod (21) is matched with the inclined slope (23) and the second extrusion rod (22) respectively, so that a variable cross-section through hole is formed in the blank.

6. A process of extrusion homogenization of low pressure turbine shaft forging as claimed in claim 2 wherein, When the temperature of any one of the upper die, the extrusion sleeve (5), the upsetting extrusion lower protrusion (6), and the lower rod forming die (7) is greater than the maximum preset temperature or less than the minimum preset temperature, the flow speed of the heat conduction medium of the heat equalizing device is increased to the maximum preset flow speed.

7. A process of extrusion homogenization of low pressure turbine shaft forging as claimed in claim 1 wherein, In the S2, the mold is placed in a heating furnace and heated to 300-500°C.

8. A process of extrusion homogenization of low pressure turbine shaft forging as claimed in claim 2 wherein, The S10 further comprises the following steps: S101: the upper die and the extrusion sleeve (5) are withdrawn; S102: the low-pressure turbine shaft forging is taken out; S103: the low-pressure turbine shaft forging is cooled to 100-300°C; S104: the extruded low-pressure turbine shaft forging is subjected to straightening treatment.

9. A process of extrusion homogenization of low pressure turbine shaft forging as claimed in claim 1 wherein, In the S4, the extrusion speed of the upper die when pressing the blank is 100-120 mm / s or 120-140 mm / s.

10. A process of extrusion homogenization of low pressure turbine shaft forging as claimed in claim 1 wherein, In the S3, the lubricant sprayed is a glass lubricant.

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