Uniform extrusion process for low-pressure turbine shaft forge piece

Abstract

The invention discloses a uniform extrusion process for a low-pressure turbine shaft forge piece. The uniform extrusion process for the low-pressure turbine shaft forge piece comprises the steps that S1, a blank is formed; s2, preheating is conducted; s3, lubricating; s4, the blank is subjected to rod feeding extrusion forming; s5, upper rod forming and heat conduction; s6, the blank is subjected to lower rod extrusion forming; s7, lower rod forming heat conduction; s8, upsetting, extruding and forming the blank; s9, upsetting, forming and conducting heat; s10, demolding is conducted; one-heating-number heating and one-step extrusion are performed on the low-pressure turbine shaft forge piece blank, so that the low-pressure turbine shaft forge piece is formed at a time, extrusion stress is more uniform, and the risks of deformation and defects of the shaft forge piece are reduced; a soaking device is used for conducting heat, so that the blank is heated more uniformly in the extrusion process, and the influence of non-uniform heating on the microstructure and the mechanical property of the blank material is reduced; the machining allowance is reduced, the machining period is shortened, the machining efficiency is improved, material waste and production cost are reduced, the final quality of the low-pressure turbine shaft forge piece is improved, and the service life of the low-pressure turbine shaft forge piece is prolonged.

Description

Technical Field

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

[0002] In the design and manufacture of aircraft engines, low-pressure turbine shaft forgings, as the core components of the transmission structure, are mainly responsible for the effective transmission of engine power and torque. In order to ensure the efficient operation and flight safety of aircraft engines, low-pressure turbine shaft forgings must have extremely high precision and reliability.

[0003] Traditionally, the production of low-pressure turbine shaft forgings mainly adopts multi-fire and multi-step die forging technology; this die forging process involves multiple heating and forging processes to gradually shape the required forging shape and size; however, multi-fire heating will lead to uneven temperature distribution inside the billet, thus affecting the microstructure and mechanical properties of the material; in addition, the uneven extrusion force during multiple forging processes will lead to uneven stress distribution inside the shaft forging, increasing the risk of deformation and defects of the shaft forging; and thus increasing the processing allowance and processing 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 forgings. Summary of the invention

[0004] In order to improve the defects in the processing of low-pressure turbine shaft forgings, in which multiple firing times and multiple working steps result in uneven heating temperature and uneven extrusion force of the billet, thereby affecting the forming efficiency and quality of the low-pressure turbine shaft forgings, the present application provides a uniform extrusion process for low-pressure turbine shaft forgings.

[0005] The present application provides a uniform extrusion process for a low-pressure turbine shaft forging using the following technical solution: A uniform extrusion process for a low-pressure turbine shaft forging, comprising: S1: Billet forming: Billet forming; S2: Preheating: The mold is heated to a preset temperature; S3: Lubrication: Spray lubricant on the surface of the blank and inside the mold respectively; S4: Extrusion forming of the billet upper rod: insert the billet into the lower die, press the upper die downward, and the upper die and the lower die cooperate to extrude the upper end of the billet to form the billet upper rod; S5: Upper rod forming heat conduction: The heat equalizing device conducts the heat from the upper mold to the lower mold; S6: extrusion molding of the lower rod of the billet: the upper die is continuously pressed downward, and the upper die and the lower die cooperate to extrude the lower end of the billet to form the lower rod of the billet; S7: Heat conduction of lower rod forming: The heat equalizing device conducts the heat from the lower mold to the upper mold; S8: rough extrusion molding of the blank: the upper die continues to press downward, and the upper die and the lower die extrude the middle position of the blank to roughen the blank; S9: Heat conduction during upsetting: The heat-dissipating device conducts the heat in the middle of the lower die to the upper and lower dies; S10: Demolding: Separate the upper die from the lower die and take out the low-pressure turbine shaft forging.

[0006] 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 in one step, the extrusion force is more uniform, and the risk of deformation and defects of the shaft forging is reduced; and heat is conducted through a heat equalizing device, so that the blank is heated more evenly during the extrusion process in the mold, reducing the influence of uneven heating on the microstructure and mechanical properties of the blank material; thereby reducing the processing allowance and processing cycle, improving processing efficiency, reducing material waste and production costs, and improving the final quality and service life of the low-pressure turbine shaft forging.

[0007] Preferably, the upper die comprises an upper die body, and an axial hole forming rod connected to the upper die body, the upper die body is provided with an upper rod forming groove, the opening end circumference of the upper rod forming groove is provided with an upsetting extrusion upper end surface, and the axial hole forming rod is inserted into the upper rod forming groove; The lower die comprises an extrusion sleeve, an upsetting extrusion lower convex edge arranged at the bottom of the extrusion sleeve, and a lower rod forming die connected to the bottom of the upsetting extrusion lower convex edge; The step S4 further comprises the following steps: S401: inserting the blank into the extrusion sleeve; S402: inserting the upper die into the extrusion sleeve; S403: the upper die is pressed downward, and the upsetting extrusion upper end surface and the upsetting extrusion lower convex edge cooperate to extrude the blank, so as to assist the blank in the upsetting primary primary forming; S404: the upper die body and the upsetting extrusion lower convex edge cooperate to extrude the blank into the upper rod forming groove to form the blank upper rod; S405: The upper die and the lower rod forming die cooperate to extrude the lower end of the blank so as to preliminarily form the lower rod of the blank.

[0008] By adopting the above technical scheme, the blank is extruded by cooperating with the upsetting extrusion upper end face and the upsetting extrusion lower convex edge to achieve the primary upsetting preliminary forming of the blank, the blank is extruded into the upper rod forming groove by cooperating with the upper die body and the upsetting extrusion lower convex edge to form the upper rod of the blank, and the lower rod of the blank is initially formed by cooperating with the upper die and the lower rod forming die to extrude the lower end of the blank; the present application realizes the upper rod forming of the blank, the preliminary forming of the lower rod of the blank, and the primary upsetting forming of the blank through the extrusion cooperation of the upper die and the lower die, thereby being able to efficiently achieve the preliminary forming of the blank; in the subsequent extrusion process of the blank, the upper rod part, the upsetting part of the blank, and the lower rod part of the blank can all be subjected to synchronous and uniform extrusion force, and this die structure and operation steps are helpful to improve the forming efficiency and quality of the blank, and ensure that the shape and size of the blank can be accurately controlled during the extrusion process.

[0009] Preferably, the step S5 further comprises the following steps: S501: the upper die continues to move downward, and the upsetting extrusion upper end surface and the upsetting extrusion lower convex edge cooperate to extrude the blank, so as to assist the upsetting of the blank in two stages and gradually forming the blank; S502: the shaft hole forming rod is inserted into the lower rod forming die, and the lower rod forming die cooperates with the upper die body and the shaft hole forming rod to extrude the blank, so that the blank lower rod is completely formed; S503: The upper die body and the lower rod forming die cooperate to extrude the blank so as to form the blank upper rod in a supplementary manner.

[0010] By adopting the above technical scheme, the upper die continues to move downward, and the upsetting extrusion upper end face and the upsetting extrusion lower convex edge work together to assist the blank in the secondary upsetting and gradual forming. This step helps the blank to gradually reach the required upsetting shape and size; in step S502, the lower rod forming die cooperates with the upper die body and the shaft hole forming rod to complete the complete forming of the lower rod of the billet, ensuring 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 cooperates with the lower rod forming die to supplement the forming of the upper rod part of the billet to improve the final shape of the upper rod part of the billet; the present application not only improves the overall forming quality of the billet, but also ensures the precise matching and dimensional consistency of each part, thereby improving the performance and reliability of the final product; through this staged fine forming process, it is possible to effectively reduce material waste, improve production efficiency, and ensure that the forgings meet strict quality standards, thereby realizing the refined operation of billet upsetting and forming.

[0011] Preferably, the step S6 further comprises the following steps: S601: the upper die continues to move downward, and the upsetting extrusion upper end surface and the upsetting extrusion lower convex edge cooperate to extrude the blank, so that the blank is completely upset and formed in three stages; S602: The lower rod forming mold cooperates with the upper mold body and the shaft hole forming rod to extrude the blank, so that the lower rod of the blank is supplementarily formed.

[0012] By adopting the above technical solution, the upper die continues to move downward, and the upper end face of the upsetting extrusion cooperates with the lower convex edge of the upsetting extrusion to perform three-stage upsetting extrusion on the blank, so that the upsetting of the blank reaches a fully formed state, ensuring the accuracy and consistency of the overall size and shape of the blank; in step S602, the lower rod forming mold cooperates with the upper die body and the shaft hole forming rod to supplement the forming of the lower rod part of the blank. This step helps to improve the detailed features of the lower rod and improve the overall quality of the finished product; the present application effectively achieves further fine adjustment and stabilization of the shape of the low-pressure turbine shaft forging through the three-stage complete upsetting of the blank and the supplementary forming of the lower rod of the blank, thereby improving the accuracy and efficiency of the blank forming, thereby ensuring that the final product can meet strict performance requirements and quality standards.

[0013] Preferably, the shaft hole forming rod includes a first extrusion rod inserted in 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 respectively to form a variable cross-section through hole in the blank.

[0014] By adopting the above technical solution, the diameter of the first extruded rod is greater than the diameter of the second extruded rod, and the transition between the first extruded rod and the second extruded rod is smoothly connected by the inclined slope surface; during the forging process, the first extruded rod, the inclined slope surface and the second extruded rod are used in coordination to effectively form a variable-section through hole inside 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 rate, and the design of the variable-section through hole provides the final product with the required strength and functional characteristics, meeting the specific requirements of aircraft engine applications.

[0015] Preferably, it also includes the step of increasing the flow velocity of the heat-conducting medium of the heat equalizing device to the maximum preset flow velocity when any temperature of the upper die, the extrusion sleeve, the upsetting extrusion lower protrusion, and the lower rod forming die is greater than the maximum preset temperature, or less than the minimum preset temperature.

[0016] By adopting the above technical solution, 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 equalizing device will automatically adjust the flow rate of the heat conducting medium to increase it to the preset maximum flow rate to quickly adjust and stabilize the temperature; this automatic adjustment mechanism ensures the temperature uniformity and accuracy of the die and the blank during the forging process, thereby preventing forging defects 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.

[0017] Preferably, in step S2, the mold is placed in a heating furnace and heated to 300° C.-500° C.

[0018] By adopting the above technical solution, preheating the mold helps to reduce thermal stress and mold deformation during the forging process, and improve the dimensional accuracy and surface quality of the forging; and preheating the mold improves production efficiency, helps to speed up the forging cycle, and reduces the time waiting for the mold to reach the working temperature; heating the mold to a temperature range of 300℃-500℃ allows the high-temperature mold to promote the forming process of the billet, and also helps to improve the forming quality and reduce the occurrence of process defects.

[0019] Preferably, the step S10 further includes the following steps: S101: the upper die and the extrusion sleeve withdraw; S102: Take out the low-pressure turbine shaft forging; S103: Cooling the low-pressure turbine shaft forging to 100° C.-300° C.; S104: Straightening the extruded low-pressure turbine shaft forging.

[0020] 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°C to 300°C in step S103, and in step S104, the extruded low-pressure turbine shaft forging is straightened to eliminate the bending or twisting that may occur during the forging process, ensuring that the forging meets the precise 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 accuracy and reliability of the low-pressure turbine shaft forging.

[0021] Preferably, in step S4, the extrusion rate of the upper die pressing the blank downward is 100 mm / s-120 mm / s or 120 mm / s-140 mm / s.

[0022] By adopting the above technical solution, the upper die presses the billet 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 billet is extruded under uniform and continuous force conditions, which is not only beneficial to the uniform deformation of the billet and filling of the mold cavity, but also can reduce the internal defects of the material that may be caused by too fast or too slow extrusion rate, such as cracks, folds or unevenness; and can also improve production efficiency, ensure the continuity and stability of the forging process, thereby improving the overall quality and performance of the forgings.

[0023] Preferably, the lubricant sprayed in step S3 is glass lubricant.

[0024] By adopting the above technical solution, glass lubricant can effectively reduce the friction between the blank and the die, reduce energy consumption and die wear during the forging process, and at the same time help the uniform flow and filling of the blank and reduce surface defects caused by friction; the use of glass lubricant can also help improve the dimensional accuracy and surface finish of the forgings, thereby improving the quality of the final product.

[0025] In summary, the present application includes at least one of the following beneficial technical effects: 1. 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 in one step, the extrusion force is more uniform, and the risk of shaft forging deformation and defects is reduced; and the heat is conducted through a heat-averaging device, so that the blank is heated more evenly during the extrusion process in the die, reducing the impact of uneven heating on the microstructure and mechanical properties of the blank material; thereby reducing the processing allowance and processing cycle, improving processing efficiency, reducing material waste and production costs, and also improving the final quality and service life of the low-pressure turbine shaft forging; 2. When the temperature of the upper die, extrusion sleeve, upsetting extrusion lower convex edge and lower rod forming die exceeds the maximum or minimum preset temperature threshold, the heat equalizing device will automatically adjust the flow rate of the heat conducting medium to increase it to the preset maximum flow rate to quickly adjust and stabilize the temperature; this automatic adjustment mechanism ensures the temperature uniformity and accuracy of the die and billet during the forging process, thereby preventing forging defects caused by excessively high or low temperature, such as deformation, cracks or uneven hardness, and improving the overall quality and production efficiency of forgings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the step flow of an embodiment of the present application.

[0027] Figure 2 It is a schematic cross-sectional structural diagram of the state in which the blank of the embodiment of the present application is inserted into the mold.

[0028] Figure 3It is a schematic diagram of the cross-sectional structure of the blank upper rod extrusion molding in the embodiment of the present application.

[0029] Figure 4 It is a schematic diagram of the cross-sectional structure of the lower rod extrusion molding of the billet in the embodiment of the present application.

[0030] Figure 5 It is a schematic diagram of the cross-sectional structure of the upsetting extrusion molding of the blank in the embodiment of the present application.

[0031] Description of reference numerals: 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 surface; 5. Extrusion sleeve; 6. Upsetting extrusion lower convex edge; 7. Lower rod forming die; 8. Heat conducting pipe; 81. Upper die spiral heat conducting pipe; 82. Sleeve spiral heat conducting pipe; 83. Upsetting spiral heat conducting pipe; 84. Lower rod spiral heat conducting pipe; 85. First telescopic heat conducting pipe; 86. Second telescopic heat conducting pipe; 9. Heat conducting medium driving mechanism; 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

[0032] The following is combined with Figure 1-5 This application is described in further detail.

[0033] The present application embodiment discloses a uniform extrusion process for a low-pressure turbine shaft forging. Figure 1 , the extrusion uniformity process of low-pressure turbine shaft forgings includes; S1: Billet forming: Billet forming; S2: Preheating: The mold is heated to a preset temperature; S3: Lubrication: Spray lubricant on the surface of the blank and inside the mold respectively; S4: Extrusion forming of the billet upper rod: insert the billet into the lower die, press the upper die downward, and the upper die and the lower die cooperate to extrude the upper end of the billet to form the billet upper rod; S5: Upper rod forming heat conduction: The heat equalizing device conducts the heat from the upper mold to the lower mold; S6: extrusion molding of the lower rod of the billet: the upper die is continuously pressed downward, and the upper die and the lower die cooperate to extrude the lower end of the billet to form the lower rod of the billet; S7: Heat conduction of lower rod forming: The heat equalizing device conducts the heat from the lower mold to the upper mold; S8: rough extrusion molding of the blank: the upper die continues to press downward, and the upper die and the lower die extrude the middle position of the blank to roughen the blank; S9: Heat conduction during upsetting: The heat-dissipating device conducts the heat in the middle of the lower die to the upper and lower dies; S10: Demolding: Separate the upper die from the lower die and take out the low-pressure turbine shaft forging.

[0034] The present application performs one-step heating and one-step extrusion on the low-pressure turbine shaft forging blank, so that the low-pressure turbine shaft forging is formed in one step, the extrusion force is more uniform, and the risk of deformation and defects of the shaft forging is reduced; and heat is conducted through a heat equalizing device, so that the blank is heated more evenly during the extrusion process in the mold, reducing the influence of uneven heating on the microstructure and mechanical properties of the blank material; thereby reducing the processing allowance and processing cycle, improving processing efficiency, reducing material waste and production costs, and also improving the final quality and service life of the low-pressure turbine shaft forging; further ensuring the safe and reliable operation of aircraft engines.

[0035] In step S4 of the present application, the upper die and the lower die cooperate to extrude the upper end of the billet so that the billet is formed on the rod. Heat is released during the extrusion process, and then in step S5, the heat on the upper die is transferred to the lower die through a heat equalizing device to balance the overall temperature of the mold and the billet. In step S6, the upper die is continuously pressed downward, and the upper die and the lower die cooperate to extrude the lower end of the billet, so that the billet is formed into a lower rod. During the extrusion process, the billet will continuously release heat, causing the temperature to increase. Then, in step S7, the heat on the lower die is transferred to the upper die through the heat equalization device, thereby improving the overall temperature balance of the mold and the billet and reducing the temperature difference. In step S8, the upper die continues to press downward, and the upper die and the lower die extrude the middle position of the billet to upset the billet and release heat. In step S9, the heat in the middle position of the lower die is transferred to the lower ends of the upper die and the lower die through the heat equalization device, thereby further improving the overall temperature balance of the die and the billet during the extrusion process; reducing the influence of uneven heating on the microstructure and mechanical properties of the billet material, and improving the processing efficiency and processing quality of the low-pressure turbine shaft forgings.

[0036] Furthermore, if Figure 2 and Figure 3 As shown, the upper die includes an upper die body 1, and an axial hole forming rod 2 connected to the upper die body 1, an upper rod forming groove 3 is provided on the upper die body 1, an upsetting extrusion upper end surface 4 is provided on the peripheral side of the opening end of the upper rod forming groove 3, and the axial hole forming rod 2 is inserted into the upper rod forming groove 3; The lower die includes an extrusion sleeve 5, an upsetting extrusion lower convex edge 6 arranged at the bottom of the extrusion sleeve 5, and a lower rod forming die 7 connected to the bottom of the upsetting extrusion lower convex edge 6; Step S4 also includes the following steps: S401: The blank is inserted into the extrusion sleeve 5; S402: The upper die is inserted into the extrusion sleeve 5; S403: the upper die is pressed downward, and the upsetting extrusion upper end surface 4 and the upsetting extrusion lower convex edge 6 cooperate to extrude the blank, so as to assist the blank in the upsetting primary forming; 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 to form a blank upper rod; 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.

[0037] In step S4 of the present application, the upper die is pressed downward, and the blank is extruded by cooperating with the upsetting extrusion upper end face 4 and the upsetting extrusion lower convex edge 6 to achieve the primary upsetting preliminary forming of the blank, and the blank is extruded into the upper rod forming groove 3 by cooperating with the upper die body 1 and the upsetting extrusion lower convex edge 6 to form the upper rod of the blank, and the lower end of the blank is extruded by cooperating with the upper die and the lower rod forming die 7 to make the lower rod of the blank initially formed; the present application realizes the upper rod forming of the blank, the preliminary forming of the lower rod of the blank, and the primary upsetting forming of the blank through the extrusion cooperation of the upper die and the lower die, thereby being able to efficiently achieve the preliminary forming of the blank; so that in the subsequent extrusion process of the blank, the upper rod part, the upsetting part of the blank, and the lower rod part of the blank can all be subjected to synchronous and uniform extrusion force, and this die structure and operation steps are helpful to improve the forming efficiency and quality of the blank, ensure that the shape and size of the blank are accurately controlled during the extrusion process, and ensure the consistency and accuracy of the forging quality, thereby meeting the product design requirements.

[0038] Furthermore, if Figure 4 As shown, step S5 also includes the following steps: S501: 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 as to assist the upsetting of the blank in two stages and gradually forming; S502: the shaft hole forming rod 2 is inserted into the lower rod forming mold 7, and the lower rod forming mold 7 cooperates with the upper mold body 1 and the shaft hole forming rod 2 to extrude the blank so that the blank lower rod is completely formed; S503: The upper die body 1 and the lower rod forming die 7 cooperate to extrude the blank so as to form the blank upper rod for supplementary forming.

[0039] In step S501 of the present application, the upper die continues to move downward, and the upsetting extrusion upper end face 4 works in conjunction with the upsetting extrusion lower convex edge 6 to assist the blank in undergoing secondary upsetting and gradual forming. This step helps the blank gradually reach the desired 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, thereby ensuring 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 supplement the forming of the upper rod part of the blank 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 precise fit and dimensional consistency of each part, thereby improving the performance and reliability of the final product; through this staged fine forming process, it is possible to effectively reduce material waste, improve production efficiency, and ensure that the forgings meet strict quality standards, thereby achieving refined operations of upsetting and forming the blank.

[0040] Specifically, Figure 5 As shown, step S6 also includes the following steps: 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 fully upset and formed in three stages; 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 supplementarily formed.

[0041] In step S601 of the present application, the upper die continues to move downward, and the upsetting extrusion upper end face 4 cooperates with the upsetting extrusion lower convex edge 6 to perform three-stage upsetting extrusion on the blank, so that the upsetting of the blank reaches a fully 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 supplement the forming of the lower rod part of the blank. This step helps to improve the detailed features of the lower rod and improve the overall quality of the finished product; the present application effectively achieves further fine adjustment and stabilization of the shape of the low-pressure turbine shaft forging through the three-stage complete upsetting of the blank and the supplementary forming of the lower rod of the blank, thereby improving the accuracy and efficiency of the blank forming, thereby ensuring that the final product can meet strict performance requirements and quality standards.

[0042] More specifically, if Figure 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 between the first extrusion rod 21 and the second extrusion rod 22; the diameter of the first extrusion rod 21 is greater 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 respectively, so that a variable-section through hole is formed in the blank.

[0043] In the present application, the diameter of the first extruded rod 21 is greater than the diameter of the second extruded rod 22, and the transition between the first extruded rod 21 and the second extruded rod 22 is smoothly connected by the inclined slope 23; during the forging process, the first extruded rod 21, the inclined slope 23 and the second extruded rod 22 are used in combination to effectively form a variable-section through hole inside 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 rate, and the design of the variable-section through hole provides the final product with the required strength and functional characteristics, meeting the specific requirements of aircraft engine applications.

[0044] In addition, if Figure 3 As shown, it also includes that when any temperature 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 velocity of the heat-conducting medium of the heat equalizing device increases to the maximum preset flow velocity.

[0045] In the present application, 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 equalizing device will automatically adjust the flow rate of the heat conducting medium to increase it to the preset maximum flow rate to quickly adjust and stabilize the temperature; this automatic adjustment mechanism ensures the temperature uniformity and accuracy of the die and blank during the forging process, thereby preventing forging defects 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.

[0046] The heat equalization device of the present application comprises a heat conducting pipe 8, a flowing heat conducting medium arranged in the heat conducting pipe 8, a heat conducting medium driving mechanism 9 connected to the heat conducting pipe 8, and a temperature detecting mechanism 10; When any temperature 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 temperature detection mechanism 10 triggers the heat-conducting medium driving mechanism 9 to drive the flow speed of the flowing heat-conducting medium to increase to the preset maximum flow speed.

[0047] The heat conducting pipe 8 includes an upper mold spiral heat conducting pipe 81 inserted in the upper mold body 1, a sleeve spiral heat conducting pipe 82 inserted in the side wall of the extrusion sleeve 5, an upset spiral heat conducting pipe 83 inserted in the upset extrusion lower convex edge 6, a lower rod spiral heat conducting pipe 84 inserted in the lower rod forming mold 7, a first telescopic heat conducting pipe 85 arranged between the upper mold spiral heat conducting pipe 81 and the sleeve spiral heat conducting pipe 82, and a second telescopic heat conducting pipe 86 arranged between the lower rod spiral heat conducting pipe 84 and the upper mold spiral heat conducting pipe 81; The upper mold spiral heat conducting pipe 81, the first telescopic heat conducting pipe 85, the sleeve spiral heat conducting pipe 82, the upsetting spiral heat conducting pipe 83, the lower rod spiral heat conducting pipe 84, and the second telescopic heat conducting pipe 86 are connected in sequence; like Figure 4 As shown, the temperature detection mechanism 10 includes an upper die temperature detection component 101 inserted in the upper die body 1, a sleeve temperature detection component 102 inserted in the side wall of the extrusion sleeve 5, an upsetting temperature detection component 103 inserted in the upsetting extrusion lower convex edge 6, and a lower rod temperature detection component 104 inserted in the lower rod forming die 7; In addition, the present application also discloses that the temperature detection mechanism 10 is also used for detecting the temperature difference between the upper mold temperature detection component 101, the sleeve temperature detection component 102, the upsetting temperature detection component 103, and the lower rod temperature detection component 104; when the temperature difference between the upper mold temperature detection component 101, the sleeve temperature detection component 102, the upsetting temperature detection component 103, and the lower rod temperature detection component 104 is greater than the preset temperature difference value, the temperature detection mechanism 10 triggers the heat-conducting medium driving mechanism 9 to drive the flow speed of the flowing heat-conducting medium to increase to the maximum preset flow speed; so as to quickly adjust and stabilize the temperature to ensure the temperature uniformity and accuracy of the mold and the blank.

[0048] The heat-conducting medium driving mechanism 9 is preferably a high-temperature medium pump, the flowing heat-conducting medium is preferably a nanofluid or thermal oil, and the temperature detection mechanism 10 is preferably a temperature sensor.

[0049] Furthermore, in step S2, the mold is placed in a heating furnace and heated to 300°C-500°C.

[0050] The present application helps to reduce thermal stress and mold deformation during the forging process, and improve the dimensional accuracy and surface quality of the forgings by preheating the mold; and preheating the mold improves production efficiency, helps to speed up the forging cycle, and reduces the time waiting for the mold to reach the working temperature; heating the mold to a temperature range of 300°C-500°C allows the high-temperature mold to promote the forming process of the billet, and also helps to improve the forming quality and reduce the occurrence of process defects.

[0051] Furthermore, step S10 further includes the following steps: S101: The upper die and the extrusion sleeve 5 exit; S102: Take out the low-pressure turbine shaft forging; S103: Cooling the low-pressure turbine shaft forging to 100° C.-300° C.; S104: Straightening the extruded low-pressure turbine shaft forging.

[0052] In order to ensure the dimensional stability of the low-pressure turbine shaft forging and reduce residual stress, the present application cools the forging to a temperature range of 100°C to 300°C in step S103, and in step S104, the extruded low-pressure turbine shaft forging is straightened to eliminate bending or twisting that may occur during the forging process, ensuring that the forging meets precise 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 accuracy and reliability of the low-pressure turbine shaft forging, making the application of the low-pressure turbine shaft forging in aircraft engines safer and longer in service life.

[0053] Furthermore, in step S4, the extrusion rate of the upper die pressing the blank is 100 mm / s-120 mm / s or 120 mm / s-140 mm / s.

[0054] The upper die of the present application presses the billet 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 billet is extruded under uniform and continuous force conditions, which is not only beneficial to the uniform deformation of the billet and filling of the mold cavity, but also can reduce the internal defects of the material that may be caused by too fast or too slow extrusion rate, such as cracks, folds or unevenness; and can also improve production efficiency, ensure the continuity and stability of the forging process, thereby improving the overall quality and performance of the forging.

[0055] Specifically, the lubricant sprayed in step S3 is glass lubricant.

[0056] The glass lubricant of the present application has high temperature resistance and good lubrication performance, and can provide a stable lubrication effect between the blank and the die during high-temperature forging; the glass lubricant can effectively reduce the friction between the blank and the die, reduce energy consumption and die wear during the forging process, and at the same time help the uniform flow and filling of the blank, and reduce 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.

[0057] The implementation principle of the uniform extrusion process of a low-pressure turbine shaft forging in the embodiment of the present application is: By heating the low-pressure turbine shaft forging blank in one step and extruding it in one step, the low-pressure turbine shaft forging is formed in one step, the extrusion force is more uniform, and the risk of shaft forging deformation and defects is reduced; and heat is conducted through a heat equalizing device, so that the blank is heated more evenly during the extrusion process in the mold, reducing the impact of uneven heating on the microstructure and mechanical properties of the blank material; thereby reducing the processing allowance and processing cycle, improving processing efficiency, reducing material waste and production costs, and improving the final quality and service life of the low-pressure turbine shaft forging; further ensuring the safe and reliable operation of aircraft engines; 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 equalizing device will automatically adjust the flow rate of the heat conducting medium to increase it to the preset maximum flow rate to quickly adjust and stabilize the temperature; this automatic adjustment mechanism ensures the temperature uniformity and accuracy of the die and blank during the forging process, thereby preventing forging defects 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.

[0058] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A uniform extrusion process for low-pressure turbine shaft forgings, characterized in that: include; S1: Billet forming: Billet forming; S2: Preheating: The mold is heated to a preset temperature; S3: Lubrication: Spray lubricant on the surface of the blank and inside the mold respectively; S4: Extrusion forming of the billet upper rod: insert the billet into the lower die, press the upper die downward, and the upper die and the lower die cooperate to extrude the upper end of the billet to form the billet upper rod; S5: Upper rod forming heat conduction: The heat equalizing device conducts the heat from the upper mold to the lower mold; S6: extrusion molding of the lower rod of the billet: the upper die is continuously pressed downward, and the upper die and the lower die cooperate to extrude the lower end of the billet to form the lower rod of the billet; S7: Heat conduction of lower rod forming: The heat equalizing device conducts the heat from the lower mold to the upper mold; S8: rough upsetting and extrusion forming of the blank: the upper die continues to press downward, and the upper die and the lower die extrude the middle position of the blank to rough upsetting the blank; S9: Heat conduction during upsetting: The heat-dissipating device conducts the heat in the middle of the lower die to the upper and lower dies; S10: Demolding: Separate the upper die from the lower die and take out the low-pressure turbine shaft forging.

2. The uniform extrusion process for a low-pressure turbine shaft forging according to claim 1, characterized in that: The upper die comprises an upper die body (1) and an axial hole forming rod (2) connected to the upper die body (1); an upper rod forming groove (3) is provided on the upper die body (1); an upsetting extrusion upper end surface (4) is provided around the opening end of the upper rod forming groove (3); and the axial hole forming rod (2) is inserted into the upper rod forming groove (3); The lower die comprises an extrusion sleeve (5), an upsetting extrusion lower convex edge (6) arranged at the bottom of the extrusion sleeve (5), and a lower rod forming die (7) connected to the bottom of the upsetting extrusion lower convex edge (6); The step S4 further comprises the following steps: S401: inserting the blank into the extrusion sleeve (5); S402: inserting the upper die into the extrusion sleeve (5); S403: the upper die is pressed downward, and the upsetting extrusion upper end surface (4) and the upsetting extrusion lower convex edge (6) cooperate to extrude the blank, so as to assist the blank in the upsetting primary primary forming; 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) to form a blank upper rod; 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.

3. The uniform extrusion process for a low-pressure turbine shaft forging according to claim 2, characterized in that: The step S5 further comprises the following steps: S501: 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 as to assist the upsetting of the blank in two stages and gradually forming the blank; S502: the shaft hole forming rod (2) is inserted into the lower rod forming mold (7), and the lower rod forming mold (7) cooperates with the upper mold 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 mold body (1) and the lower rod forming mold (7) cooperate to extrude the blank so as to supplement the upper rod of the blank.

4. The uniform extrusion process for a low-pressure turbine shaft forging according to claim 2, characterized in that: The step S6 further comprises the following steps: 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 fully upset and formed in three stages; S602: The lower rod forming mold (7) cooperates with the upper mold body (1) and the shaft hole forming rod (2) to extrude the blank, so that the lower rod of the blank is supplementarily formed.

5. The uniform extrusion process for a low-pressure turbine shaft forging according to claim 2, characterized in that: 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 to the end of the first extrusion rod (21), and an inclined slope (23) provided at the connection position between the first extrusion rod (21) and the second extrusion rod (22); the diameter of the first extrusion rod (21) is greater 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) respectively, so that a variable-section through hole is formed in the blank.

6. The uniform extrusion process for a low-pressure turbine shaft forging according to claim 2, characterized in that: It also includes the step of increasing the flow rate of the heat-conducting medium of the heat-equalizing device to the maximum preset flow rate when any temperature 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.

7. The uniform extrusion process for a low-pressure turbine shaft forging according to claim 1, characterized in that: In the step S2, the mold is placed in a heating furnace and heated to 300° C.-500° C.

8. The uniform extrusion process for a low-pressure turbine shaft forging according to claim 2, characterized in that: The step S10 further includes the following steps: S101: the upper die and the extrusion sleeve (5) withdraw; S102: Take out the low-pressure turbine shaft forging; S103: Cooling the low-pressure turbine shaft forging to 100° C.-300° C.; S104: Straightening the extruded low-pressure turbine shaft forging.

9. The uniform extrusion process for a low-pressure turbine shaft forging according to claim 1, characterized in that: In step S4, the extrusion rate of the upper die pressing the blank is 100 mm / s-120 mm / s or 120 mm / s-140 mm / s.

10. The uniform extrusion process for a low-pressure turbine shaft forging according to claim 1, characterized in that: The lubricant sprayed in step S3 is glass lubricant.

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