Closed upset extrusion forming device and method

Abstract

The application discloses a closed upsetting-extruding forming device and method, and relates to the field of forming devices.The closed upsetting-extruding forming device comprises a lower die assembly, a punch, a floating extruding cylinder and an upper die assembly; the lower die assembly and the upper die assembly are oppositely arranged at a first preset distance; the floating extruding cylinder is arranged between the upper die assembly and the lower die assembly; the punch is sealingly and slidably arranged in the lower die cavity and can slide along the lower die assembly to the inner cavity of the floating extruding cylinder; and the bottom end of the punch is used for extruding a blank. The punch is used for extruding the blank, the one-time integral closed upsetting-extruding forming of a formed part can be realized, and the multi-step forming process of the disc part and the shaft part of the formed part is combined; the integral closed upsetting-extruding forming extrudes the shaft part at the same time of the disc part upsetting forming in one forging fire, the critical small deformation zone of the disc-shaft transition zone is fundamentally eliminated, the abnormal grain growth defect of the disc-shaft transition zone is avoided, the material utilization rate is improved, and the uniform distribution of the strain field of the disc-shaft integrated turbine disc is realized.

Description

Technical Field

[0001] This invention relates to the field of hot working technology, and in particular to a closed-loop upsetting and extrusion forming apparatus and method. Background Technology

[0002] With the continuous improvement of the power and power-to-weight ratio of aero engines, the design of turbine disk structures is becoming increasingly larger, more complex, and more integrated.

[0003] Currently, turbine disks mostly adopt a complex integrated disk-shaft structure design, consisting of a large-diameter, thin disk and a slender shaft. The ratio of the shaft length to the disk rim thickness can reach over 6. This means the integrated disk-shaft component is composed of a large, thin disk and a slender, long shaft, making it a highly complex and difficult-to-form disk component. Traditional die forging processes must achieve both the overall shape of the component and precise control of its microstructure and properties; both are crucial and indispensable, and they also influence and constrain each other. This characteristic becomes more pronounced as the ratio of the turbine disk shaft length to the disk rim thickness increases.

[0004] Existing forging methods for complex turbine disk components mainly include multi-step forging, reverse extrusion, and integral die forging. Die forging of the disk body followed by free drawing of the long rod to form an integrated disk-shaft part requires numerous heat treatments, inevitably leading to defects in microstructure uniformity control. Furthermore, the higher the alloying degree, the more difficult the microstructure control becomes, making it difficult to meet the metallurgical quality control requirements of high-performance integrated disk-shaft turbine disks. Reverse extrusion forging produces both the disk and rod sections of the disk-shaft forging in a single process, resulting in a reasonable flow line distribution. However, the disk section undergoes almost no deformation during reverse extrusion, while the rod region is formed with large deformation through reverse extrusion, leading to significant differences in the alloy microstructure between the disk body and the rod. In integral die forging, the resistance encountered in forming the slender shaft section is much greater than that encountered in forming the disk body and burrs. Generally, increasing the machining allowance for the shaft section is used, but a large amount of metal is lost from the burrs during the forming process. Therefore, only short, protruding integrated disk-shaft components can be formed, failing to meet the overall shape requirements of integrated disk-shaft turbine disks with longer shaft sections. The above methods pose serious challenges to process control, and alloy fibers (streamlines) are difficult to guarantee, resulting in poor product quality consistency. Summary of the Invention

[0005] In view of this, the first objective of the present invention is to provide a closed-loop upsetting forming apparatus to solve the problems of poor microstructure consistency and low material utilization during turbine disk forming.

[0006] A second objective of this invention is to provide a closed-loop upsetting method.

[0007] To achieve the first objective mentioned above, the present invention provides the following solution:

[0008] A closed-type upsetting forming apparatus includes a lower die assembly, a punch, a floating extrusion cylinder, and an upper die assembly;

[0009] The lower mold assembly is opposite to the upper mold assembly and is set at a first preset distance;

[0010] The floating extrusion cylinder is placed between the upper die assembly and the lower die assembly. Its top end is sealed and slidably installed in the upper die cavity of the upper die assembly, and its bottom end is sealed and slidably installed in the lower die cavity of the lower die assembly. The bottom end of the floating extrusion cylinder is limited and abutted against the first limiting step provided on the side wall of the lower die cavity, and has a preset gap with the bottom of the lower die cavity. The bottom of the lower die cavity is used to support the blank.

[0011] The punch is sealed and slidably installed in the lower die cavity, and can slide along the lower die assembly to the inner cavity of the floating extrusion cylinder. The bottom end of the punch is used to extrude the blank. After the blank is extruded and deformed, the portion that fills the floating extrusion cylinder forms the shaft portion of the molded part. After the blank is extruded and deformed, the portion that fills the preset gap and lifts the floating extrusion cylinder to move a second preset distance closer to the upper die assembly forms the disc portion of the molded part.

[0012] In one specific implementation, the sidewall of the upper mold cavity is provided with a second limiting step that abuts against the top limit of the floating extrusion cylinder.

[0013] In another specific embodiment, the outer wall of the floating extrusion cylinder is provided with a third limiting step for abutting against the bottom end of the upper die assembly;

[0014] When the top of the floating extrusion cylinder comes into contact with the second limiting step, the third limiting step of the floating extrusion cylinder comes into contact with the bottom of the upper mold assembly.

[0015] In another specific embodiment, the closed upsetting forming apparatus further includes an elastic component;

[0016] One end of the elastic component is connected to the upper mold component, and the other end is connected to the third limiting step;

[0017] At least one of the upper mold assembly and the third limiting step is provided with a receiving groove for accommodating the elastic component.

[0018] In another specific implementation, the resilient component includes:

[0019] A guide connecting rod, one end of which is connected to the third limiting step, and the other end of which is slidably connected to the upper mold assembly;

[0020] An elastic element is sleeved outside the guide connecting rod, one end of which abuts against the bottom end of the upper mold assembly, and the other end abuts against the top end of the third limiting step.

[0021] In another specific embodiment, the punch includes:

[0022] A sliding part that is slidably connected to the inner wall of the upper mold cavity; and

[0023] An extrusion section is connected at its top end to the bottom end of the sliding section. The bottom end of the extrusion section is used to extrude the top end of the blank, and the cross-section of the extrusion section is smaller than the cross-section of the sliding section.

[0024] In another specific embodiment, the blank, the extrusion section, and the sliding section are all cylindrical structures, and the diameter of the blank, D0, is ≤ 1.5 × D1, where D1 is the diameter of the extrusion section;

[0025] The diameter D2 of the sliding part is greater than or equal to 1D1+2d, where d is the wall thickness of the hollow shaft of the molded part.

[0026] The preset gap H0 = (0.1~0.5) × H2, where H2 is the thickness of the disc portion of the molded part.

[0027] In another specific implementation, the lower mold assembly includes:

[0028] Lower mold base;

[0029] The lower mold is installed at the top of the lower mold base;

[0030] A lower die washer is installed in the inner cavity of the lower die, and the top end of the lower die washer and the bottom end of the floating extrusion cylinder have the preset gap.

[0031] The ejector rod passes through the lower mold base and the lower mold, and is used to support the blank and eject the molded part after molding.

[0032] The various embodiments of the present invention can be combined arbitrarily as needed, and the resulting embodiments are also within the scope of the present invention and are part of the specific implementation of the present invention.

[0033] To achieve the second objective mentioned above, the present invention provides the following solution:

[0034] A closed-loop upsetting method includes:

[0035] Step S1: Provide a closed upsetting forming apparatus as described in any one of the above.

[0036] Step S2: After sandblasting and coating the outer surface of the blank with glass lubricant, place it in a heating furnace for heating and heat preservation;

[0037] Step S3: Place the blank after the heat preservation is completed at the bottom of the lower mold cavity;

[0038] Step S4: Start the press to make the punch move downward, which will drive the floating extrusion cylinder into the lower die cavity. At the same time, the floating extrusion cylinder stops moving downward after it abuts against the first limiting step in the lower die cavity.

[0039] Step S5: Continue to drive the punch downwards and contact the blank, continue to apply pressure, so that the blank undergoes upsetting deformation in the bottom of the floating extrusion cylinder and the lower die cavity;

[0040] Step S6: Continue to drive the punch downwards. The blank fills the cavity formed by the lower die cavity and the floating extrusion cylinder under pressure. The blank continuously fills radially and reacts on the floating extrusion cylinder. The floating extrusion cylinder continuously floats upwards to form the disc part of the molded part. At the same time, the blank flows in the opposite direction along the axial direction of the punch to form the shaft part of the molded part.

[0041] In one specific implementation, step S6 is followed by step S7: after the back extrusion is completed, the upper die assembly is lifted, and the elastic element of the closed upsetting forming device reacts to the disc of the forming part through the floating extrusion cylinder, so that the shaft of the forming part is separated from the punch and placed on the lower die washer and ejector rod of the lower die assembly, and the ejector rod is driven upward to push the forming part out of the lower die assembly;

[0042] and / or

[0043] The heating and holding time in step S1 is T = D0 × (1.0 ~ 1.5) min / mm, where D0 is the diameter of the billet.

[0044] The closed-loop upsetting forming apparatus provided by this invention enables one-time closed-loop upsetting forming of the forming part by extruding the blank with a punch, combining the multi-step forming process of the disc and shaft parts of the forming part; the overall closed-loop upsetting forming simultaneously upsetting the disc part in a forging furnace and back-extruding the shaft part, fundamentally eliminating the critical small deformation zone in the disc-shaft transition zone, avoiding abnormal grain growth defects in the disc-shaft transition zone, improving material utilization, achieving uniform distribution of the strain field of the integrated disc-shaft turbine disk, and obtaining forgings with better uniformity of microstructure and properties, providing a new technical approach for the preparation of complex integrated disc-shaft turbine disks required for high-performance aero engines. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any novel effort.

[0046] Figure 1 This is a cross-sectional view of the closed upsetting forming device provided by the present invention when a blank is placed in it.

[0047] Figure 2 This is a cross-sectional view of the closed upsetting forming device provided by the present invention when the blank is placed in its initial state.

[0048] Figure 3 This is a cross-sectional structural diagram of the billet during upsetting deformation in the closed upsetting extrusion forming device provided by the present invention.

[0049] Figure 4 This is a cross-sectional view of the blank before it contacts the sliding part of the punch and the top of the floating extrusion cylinder in the closed upsetting forming device provided by the present invention.

[0050] Figure 5 This is a cross-sectional view of the bar billet at the end of upsetting in the closed upsetting forming apparatus provided by the present invention.

[0051] Figure 6 A cross-sectional structural schematic diagram of the molded part produced by the closed-loop upsetting method provided by the present invention;

[0052] Figure 7 This is a schematic diagram of the microstructure of the disc portion of the molded part produced by the present invention.

[0053] Figure 8 This is a schematic diagram of the microstructure of the shaft portion of the molded part produced by the present invention.

[0054] Figure 9 This is a schematic diagram of the microstructure of the transition area between the disc and shaft portions of the molded part processed by the present invention.

[0055] in, Figures 1-9 middle:

[0056] Closed-type upsetting forming device 1000, lower die 103, lower die base 102, lower die washer 104, lower die assembly 100, floating extrusion cylinder 300, upper die assembly 400, first limiting step 101, blank 2000, second limiting step 401, third limiting step 301, elastic component 500, guide connecting rod 501, elastic element 602, sliding part 201, extrusion part 202, ejector rod 105, upper die base 402, punch 200, punch outer sleeve 403. Detailed Implementation

[0057] The following will refer to the appendices in the embodiments of the present invention. Figures 1-9 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0058] In the description of this invention, it should be understood that the terms "upper," "lower," "top surface," "bottom surface," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the indicated position or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] like Figures 1-5 As shown, the first aspect of the present invention provides a closed-loop upsetting forming apparatus 1000 for forming a disc shaft component. Specifically, the ratio of the shaft length to the thickness of the disc portion of the disc shaft component can be 3 or more. Figure 6 As shown.

[0060] The closed upsetting forming device 1000 includes a lower die assembly 100, a punch 200, a floating extrusion cylinder 300, and an upper die assembly 400.

[0061] The lower mold assembly 100 is opposite to the upper mold assembly 400 and is set at a first preset distance, such as... Figure 1As shown, the upper mold assembly 400 is located above the lower mold assembly 100. It should be noted that the relative arrangement of the lower mold assembly 100 and the upper mold assembly 400 means that the opening of the upper mold cavity of the upper mold assembly 400 is directly opposite the opening of the lower mold cavity of the lower mold assembly 100. The first preset distance is determined according to the part to be molded. The upper mold assembly 400 includes an upper mold base 402 and a punch sleeve 403. The top end of the punch sleeve 403 is connected to the bottom end of the upper mold base 402. The upper mold base 402 and the punch sleeve 403 are respectively provided with a coaxial first sliding cavity and a second sliding cavity. The bottom end of the first sliding cavity communicates with the top end of the second sliding cavity, and the first sliding cavity and the second sliding cavity together enclose the upper mold cavity. The punch 200 is sealed to and slidably connected to both the first sliding cavity and the second sliding cavity.

[0062] A floating extrusion cylinder 300 is positioned between the upper die assembly 400 and the lower die assembly 100. Its top end is sealed and slidably mounted within the upper die cavity of the upper die assembly 400, and its bottom end is sealed and slidably mounted within the lower die cavity of the lower die assembly 100. Specifically, as... Figure 1 As shown, the outer wall of the top end of the floating extrusion cylinder 300 is sealed to the inner wall of the upper mold cavity and can be slidably connected, and the outer wall of the bottom end of the floating extrusion cylinder 300 is sealed to the inner wall of the lower mold cavity and can be slidably connected.

[0063] Before the extrusion of the billet 2000 begins, the bottom end of the floating extrusion cylinder 300 abuts against the first limiting step 101 provided on the side wall of the lower die cavity, and has a preset gap with the bottom of the lower die cavity, which supports the billet 2000. In this embodiment, the billet 2000 is taken as a bar billet, such as... Figure 1 As shown. It should be noted that the blank 2000 placed at the bottom of the lower mold cavity is the blank 2000 that has been sandblasted, coated with glass lubricant, and then placed in a resistance heating furnace for heating and heat preservation, and the heat preservation is completed.

[0064] The top end of the punch 200 is used to connect to the drive end of the press, and the bottom end is sealed and slidably installed in the lower die cavity, and can slide along the lower die assembly 100 to the inner cavity of the floating extrusion cylinder 300. Specifically, the floating extrusion cylinder 300 is coaxially arranged with the upper die cavity, which facilitates the punch 200 to enter the floating extrusion cylinder 300 from the upper die cavity.

[0065] The bottom end of the punch 200 is used to extrude the blank 2000. After the blank 2000 is extruded and deformed, the part that fills into the floating extrusion cylinder 300 forms the shaft part of the molded part. After the blank 2000 is extruded and deformed, the part that fills the preset gap and lifts the floating extrusion cylinder 300 to move a second preset distance toward the upper die assembly 400 forms the disc part of the molded part.

[0066] The closed-loop upsetting forming apparatus 1000 provided by this invention can achieve one-time closed-loop upsetting forming of the forming part by extruding the blank 2000 through the punch 200, and combine the multi-step forming process of the disc and shaft parts of the forming part. The overall closed-loop upsetting forming simultaneously upsetting the disc part in a forging fire and back-extruding the shaft part, fundamentally eliminates the critical small deformation zone of the disc-shaft transition zone, avoids abnormal grain growth defects in the disc-shaft transition zone, improves material utilization, achieves uniform distribution of strain field of the integrated disc-shaft turbine disk, and obtains forgings with better uniformity of microstructure and properties, providing a new technical approach for the preparation of complex integrated disc-shaft turbine disks required for high-performance aero engines.

[0067] In some embodiments, the sidewall of the upper mold cavity is provided with a second limiting step 401 that abuts against the top end of the floating extrusion cylinder 300. The provision of the second limiting step 401 limits the upward distance of the floating extrusion cylinder 300, avoiding the problem that excessive upward movement of the floating extrusion cylinder 300 would result in the molded part not meeting the usage requirements.

[0068] It should be noted that the second limiting step 401 can be a step block that is evenly distributed in a ring around the axis of the upper mold cavity on the inner wall of the upper mold cavity, or it can be an annular step set in the inner wall of the upper mold cavity around the axis of the upper mold cavity, etc.

[0069] Furthermore, the present invention discloses that the outer wall of the floating extrusion cylinder 300 is provided with a third limiting step 301, wherein the third limiting step 301 is used to abut against the bottom end of the upper mold assembly 400.

[0070] When the top of the floating extrusion cylinder 300 comes into contact with the second limiting step 401, the third limiting step 301 of the floating extrusion cylinder 300 comes into contact with the bottom of the upper mold assembly 400.

[0071] The setting of the third limiting step 301 further limits the upward movement of the floating extrusion cylinder 300, improving the accuracy of the upward displacement of the floating extrusion cylinder 300.

[0072] Specifically, the third limiting step 301 can be an annular limiting step, or it can be a block-shaped step that is evenly distributed in an annular interval along the axis of the floating extrusion cylinder 300 on the outer wall of the floating extrusion cylinder 300.

[0073] In some embodiments, the closed upsetting forming apparatus 1000 further includes an elastic component 500, wherein one end of the elastic component 500 is connected to the upper die assembly 400, and the other end is connected to the third limiting step 301. That is, the connection between the upper die assembly 400 and the floating extrusion cylinder 300 is achieved through the elastic component 500.

[0074] At least one of the upper mold assembly 400 and the third limiting step 301 is provided with a receiving groove for accommodating the elastic component 500. The receiving groove is provided so that the elastic component 500 can be accommodated in the receiving groove when it is compressed, thereby preventing the top surface of the third limiting step 301 from failing to fit and abut against the bottom surface of the upper mold assembly 400.

[0075] The elastic component 500 provides a counterforce to the floating extrusion cylinder 300 during demolding, which then transmits the force to the disc portion of the molded part, allowing the shaft portion to separate smoothly from the punch 200. This invention achieves smooth demolding of disc-shaft components with slender shafts after molding through flexible back pressure, further improving production efficiency and enabling mass production of various complex disc-shaft integrated components on the same device.

[0076] It should be noted that the provision of the elastic component 500 is only one specific embodiment of the present invention. In practical applications, the elastic component 500 may not be provided.

[0077] Specifically, the elastic component 500 includes a guide connecting rod 501 and an elastic element 502. One end of the guide connecting rod 501 is connected to the third limiting step 301, and the other end is slidably connected to the upper mold assembly 400. The elastic element 502 is sleeved on the guide connecting rod 501, with one end abutting against the bottom end of the upper mold assembly 400 and the other end abutting against the top end of the third limiting step 301.

[0078] After the extruded blank 2000 is completed, the upper die assembly 400 is lifted. At this time, the elastic element 502 reacts to the third limiting step 301. The third limiting step 301 transmits the force to the disc part of the formed part through the floating extrusion cylinder 300, so that the shaft part can be smoothly removed from the punch 200.

[0079] Specifically, the elastic element 502 can be a spring or other elastic element 502. It should be noted that the number of elastic components 500 can be set to at least 2 groups, and each group of elastic components 500 is evenly distributed in a ring around the axis of the floating extrusion cylinder 300 on the third limiting step 301 of the floating extrusion cylinder 300.

[0080] Specifically, the guide connecting rod 501 can be a bolt. A countersunk hole is provided on the upper mold assembly 400, the bolt nut is confined within the countersunk hole, and the bolt shank passes through the countersunk hole and is securely connected to the third limiting step 301. Alternatively, the connecting rod can include a rod portion, a first limiting cover, and a second limiting cover. One end of the rod portion passes through the upper mold assembly 400 and connects to the first limiting cover. The bottom end of the first limiting cover abuts against the top end of the upper mold assembly 400. The other end of the rod portion extends to the top end of the third limiting step 301 and connects to the second limiting cover. The second limiting cover is securely connected to the third limiting step 301. At least one of the first and second limiting covers can be detachably connected to the rod portion to facilitate the assembly and disassembly of the floating extrusion cylinder 300.

[0081] In some embodiments, the punch 200 includes a sliding portion 201 and a pressing portion 202. The sliding portion 201 is a columnar structure of equal diameter and is slidably connected to the inner wall of the upper die cavity.

[0082] The extrusion section 202 is a columnar structure of equal diameter, and the extrusion section 202 and the sliding section 201 are coaxially arranged. The top end of the extrusion section 202 is connected to the bottom end of the sliding section 201. The bottom end of the extrusion section 202 is used to extrude the top end of the blank 2000, and the cross-section of the extrusion section 202 is smaller than the cross-section of the sliding section 201. That is to say, the extruded shaft is a hollow shaft.

[0083] Of course, the diameters of the extrusion part 202 and the sliding part 201 can also be set to be equal. In this case, the extruded shaft part is a solid shaft.

[0084] In some embodiments, the billet 2000, the extrusion section 202, and the sliding section 201 are all cylindrical structures, and the diameter D0 of the billet 2000 is ≤ 1.5 × D1, where D1 is the diameter of the extrusion section 202. Figure 2 As shown. The diameter D0 of the billet 2000 is determined according to the above formula to prevent abnormal grain growth due to excessively large diameter of billet 2000 and small upsetting deformation. At the same time, it avoids the asynchronous phenomenon of reverse extrusion forming of slender hollow shaft and upsetting forming of disc.

[0085] Furthermore, through numerous creative experiments, the inventors of this invention have determined that the diameter D2 of the sliding part 201 ≥ D1 + 2d, where d is the wall thickness of the hollow shaft of the molded part. The molded part achieves the best results when the diameter of the sliding part 201 satisfies the conditions of the above formula.

[0086] Furthermore, the present invention discloses a preset gap H0 = (0.1~0.5)×H2, where H2 is the thickness of the disk portion of the molded part. Under this condition, the probability of abnormal grains in the disk-shaft transition zone of the molded part is the lowest.

[0087] In some embodiments, the lower mold assembly 100 includes a lower mold base 102, a lower mold 103, a lower mold washer 104, and an ejector rod 105, wherein the lower mold 103 is mounted on the top of the lower mold base 102.

[0088] The lower die washer 104 is installed in the inner cavity of the lower die 103. Specifically, the inner hole of the lower die washer 104, the inner cavity of the lower die 103, and the floating extrusion cylinder 300 are all coaxially arranged. There is a preset gap between the top end of the lower die washer 104 and the bottom end of the floating extrusion cylinder 300. The lower die 103, the lower die washer 104, and the ejector rod 105 enclose the lower die cavity.

[0089] Understandably, by setting different thicknesses H1 of the lower die washer 104, it is possible to obtain molded parts with different thicknesses of the disc portion, thereby improving the versatility of the closed-type upsetting forming device 1000. By changing the inner diameter of the floating extrusion cylinder 300 and the inner diameter of the lower die washer 104, the forming of integrated disc-shaft components with different size requirements can be met.

[0090] The ejector rod 105 passes through the lower mold base 102 and the lower mold 103, and is used to support the blank 2000 and to eject the molded part after molding. Specifically, as shown... Figure 1 As shown, the ejector rod 105 is flush with the bottom of the inner cavity of the lower mold 103, and the ejector rod 105 can pass through the inner hole of the lower mold washer 104 to eject the molded part.

[0091] In this invention, the integral closed-loop upsetting and extrusion forming process involves upsetting the disk portion in a single forging cycle while simultaneously back-extruding a slender, hollow shaft portion. This fundamentally eliminates the critical small deformation zone in the disk-shaft transition area, avoids abnormal grain growth defects in the transition area, and prevents partial area burn-out during multi-process forming. This improves production efficiency and material utilization, achieves a uniform distribution of the strain field in the integrated disk-shaft turbine disk, and yields forgings with superior uniform structure and properties. This provides a new technical approach for the fabrication of complex integrated disk-shaft turbine disks required for high-performance aero-engines. Furthermore, by incorporating an elastic element 502 with back pressure tension in the floating extrusion cylinder 300, this invention achieves smooth demolding of the disk-shaft component with a slender, hollow shaft after forming through flexible back pressure, further improving production efficiency. Moreover, it enables the batch production of multiple types of complex integrated disk-shaft components on the same device.

[0092] A second aspect of the present invention provides a closed-loop upsetting method, comprising:

[0093] Step S1: Provide a closed upsetting forming apparatus 1000 as described in any of the above embodiments.

[0094] Step S2: After sandblasting the outer surface of the blank 2000 and coating it with glass lubricant, place it in a heating furnace for heating and heat preservation.

[0095] The present invention facilitates the extrusion deformation of the blank 2000 by sandblasting and coating the outer surface of the blank 2000 with glass lubricant.

[0096] Specifically, taking billet 2000 as an example, the heating and holding time T = D0 × (1.0~1.5) min / mm, where D0 is the diameter of billet 2000.

[0097] Step S3: Place the blank 2000 after the heat preservation is completed at the bottom of the lower mold cavity.

[0098] At this time, the upper die assembly 400 of the closed upsetting forming device 1000 has not yet closed with the lower die assembly 100. That is, the lower die cavity of the lower die assembly 100 is in an open state, which facilitates the placement of the blank 2000. Specifically, the blank 2000 is placed at the center position of the ejector rod 105, that is, the axis of the blank 2000 coincides with the axis of the ejector rod 105.

[0099] Step S4: Start the press to make the punch 200 descend, which will drive the floating extrusion cylinder 300 into the lower die cavity. At the same time, the floating extrusion cylinder 300 stops descending after it comes into contact with the first limit step 101 in the lower die cavity.

[0100] In other words, after the blank 2000 is placed in, the upper die assembly 400 and the lower die assembly 100 are closed. At this time, the punch 200 has not yet descended. The punch 200, the floating extrusion cylinder 300, the ejector pin 105, the lower die 103, and the lower die washer 104 form the initial cavity. Figure 2 As shown.

[0101] Step S5: Continue to drive the punch 200 downward and into contact with the blank 2000, continue to apply pressure, so that the blank 2000 undergoes upsetting deformation in the floating extrusion cylinder 300 and the bottom of the lower die cavity.

[0102] The state at this stage is as follows: Figure 3 As shown.

[0103] Step S6: Continue driving the punch 200 downward. Under pressure, the blank 2000 fills the cavity formed by the lower die cavity and the floating extrusion cylinder 300. The blank 2000 continuously fills radially and reacts on the floating extrusion cylinder 300. The floating extrusion cylinder 300 continuously floats upward to form the disc part of the molded part. At the same time, the blank 2000 flows in the opposite direction along the axial direction of the punch 200, and then back-extrudes to form the shaft part of the molded part.

[0104] The state at this stage is as follows: Figure 4 and Figure 5 As shown.

[0105] Furthermore, the present invention discloses that after step S6, it also includes step S7: after the back extrusion is completed, the upper die assembly 400 is lifted, and the elastic element 502 of the closed upsetting forming device 1000 reacts to the disc portion of the forming part through the floating extrusion cylinder 300, so that the shaft portion of the forming part is separated from the punch 200 and placed on the lower die washer 104 and the ejector rod 105 of the lower die assembly 100, and the ejector rod 105 is driven upward to push the forming part out of the lower die assembly 100.

[0106] The obtained molded parts, such as Figure 6 As shown. Combined with Figures 7-9 As shown, the grains in the disk, shaft, and disk-shaft transition areas are consistent, and the microstructure and properties are uniform.

[0107] In this invention, the elastic component 500 facilitates the separation of the molded part from the punch 200.

[0108] Furthermore, the present invention discloses that after step S7, it also includes step S8: heat treatment to strengthen the obtained molded part.

[0109] The strength of the formed part is increased by setting step S8. It should be noted that the present invention is not only applicable to the integral forming of turbine forgings with integrated disc and shaft, but also applicable to the integral forming of forgings with similar structures such as flanges and long shaft integral components.

[0110] It should be noted that words indicating direction in this article, such as "up" and "down," are all in the format of "upper" and "lower." Figure 1 The orientation settings in the text are for ease of description only and have no other specific meaning.

[0111] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0112] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0113] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0114] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A closed-loop upsetting and extrusion forming device, characterized in that, Includes the lower die assembly, punch, floating extrusion cylinder, and upper die assembly; The lower mold assembly is opposite to the upper mold assembly and is set at a first preset distance; The floating extrusion cylinder is placed between the upper die assembly and the lower die assembly. Its top end is sealed and slidably installed in the upper die cavity of the upper die assembly, and its bottom end is sealed and slidably installed in the lower die cavity of the lower die assembly. The bottom end of the floating extrusion cylinder is limited and abutted against the first limiting step provided on the side wall of the lower die cavity, and has a preset gap with the bottom of the lower die cavity. The bottom of the lower die cavity is used to support the blank. The punch is sealed and slidably installed in the lower die cavity, and can slide along the lower die assembly to the inner cavity of the floating extrusion cylinder. The bottom end of the punch is used to extrude the blank. After the blank is extruded and deformed, the portion that fills the floating extrusion cylinder forms the shaft portion of the molded part. After the blank is extruded and deformed, the portion that fills the preset gap and lifts the floating extrusion cylinder to move a second preset distance closer to the upper die assembly forms the disc portion of the molded part.

2. The closed-type upsetting and extrusion forming apparatus according to claim 1, characterized in that, The side wall of the upper mold cavity is provided with a second limiting step that abuts against the top limit of the floating extrusion cylinder.

3. The closed-type upsetting and extrusion forming apparatus according to claim 2, characterized in that, The outer wall of the floating extrusion cylinder is provided with a third limiting step for abutting against the bottom end of the upper die assembly; When the top of the floating extrusion cylinder comes into contact with the second limiting step, the third limiting step of the floating extrusion cylinder comes into contact with the bottom of the upper mold assembly.

4. The closed-type upsetting and extrusion forming apparatus according to claim 3, characterized in that, It also includes resilient components; One end of the elastic component is connected to the upper mold component, and the other end is connected to the third limiting step; At least one of the upper mold assembly and the third limiting step is provided with a receiving groove for accommodating the elastic component.

5. The closed-type upsetting and extrusion forming apparatus according to claim 4, characterized in that, The elastic component includes: A guide connecting rod, one end of which is connected to the third limiting step, and the other end of which is slidably connected to the upper mold assembly; An elastic element is sleeved outside the guide connecting rod, one end of which abuts against the bottom end of the upper mold assembly, and the other end abuts against the top end of the third limiting step.

6. The closed-loop upsetting and extrusion forming apparatus according to claim 5, characterized in that, The punch includes: The sliding part is sealed and slidably connected to the inner wall of the upper mold cavity; and An extrusion section is connected at its top end to the bottom end of the sliding section. The bottom end of the extrusion section is used to extrude the top end of the blank, and the cross-section of the extrusion section is smaller than the cross-section of the sliding section.

7. The closed-type upsetting and extrusion forming apparatus according to claim 6, characterized in that, The blank, the extrusion section, and the sliding section are all cylindrical structures, and the diameter of the blank, D0, is less than or equal to 1.5 × D1, where D1 is the diameter of the extrusion section. The diameter of the sliding part, D2, is greater than or equal to D1 + 2d, where d is the wall thickness of the hollow shaft of the molded part. The preset gap H0 = (0.1~0.5) × H2, where H2 is the thickness of the disc portion of the molded part.

8. The closed-type upsetting and extrusion forming apparatus according to claim 7, characterized in that, The lower mold assembly includes: Lower mold base; The lower mold is installed at the top of the lower mold base; A lower die washer is installed in the inner cavity of the lower die, and the top end of the lower die washer and the bottom end of the floating extrusion cylinder have the preset gap. The ejector rod passes through the lower mold base and the lower mold, and is used to support the blank and eject the molded part after molding.

9. A closed-loop upsetting method, characterized in that, include: Step S1: Provide a closed-loop upsetting apparatus as described in claim 8; Step S2: After sandblasting and coating the outer surface of the blank with glass lubricant, place it in a heating furnace for heating and heat preservation; Step S3: Place the blank after the heat preservation is completed at the bottom of the lower mold cavity; Step S4: Start the press to make the punch move downward, which will drive the floating extrusion cylinder into the lower die cavity. At the same time, the floating extrusion cylinder stops moving downward after it abuts against the first limiting step in the lower die cavity. Step S5: Continue to drive the punch downwards and contact the blank, continue to apply pressure, so that the blank undergoes upsetting deformation in the bottom of the floating extrusion cylinder and the lower die cavity; Step S6: Continue to drive the punch downwards. The blank fills the cavity formed by the lower die cavity and the floating extrusion cylinder under pressure. The blank continuously fills radially and reacts on the floating extrusion cylinder. The floating extrusion cylinder continuously floats upwards to form the disc part of the molded part. At the same time, the blank flows in the opposite direction along the axial direction of the punch to form the shaft part of the molded part.

10. The closed-loop upsetting method according to claim 9, characterized in that, Step S6 is followed by step S7: After the back extrusion is completed, the upper die assembly is lifted, and the elastic element of the closed upsetting forming device reacts to the disc of the forming part through the floating extrusion cylinder, so that the shaft of the forming part is separated from the punch and placed on the lower die washer and ejector rod of the lower die assembly, and the ejector rod is driven upward to push the forming part out of the lower die assembly. and / or The heating and holding time in step S1 is T = D0 × (1.0~1.5) min / mm, where D0 is the diameter of the billet.

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