An improved bearing inner ring forging process and processing equipment

Abstract

The present application discloses an improved forging process for bearing inner rings and its processing equipment, relating to the technical field of part forging processes, including blank preparation, roughing, reverse extrusion molding, punching, flattening, reaming, and finishing. The process involves roughing the blank so that its middle section bulges outward by a certain arc, facilitating subsequent positioning and deformation of the blank. The blank is subjected to reverse extrusion processing using a special punch and die, forming a preliminary shape close to that of the finished product. Punching and flattening further refine the blank shape, helping to reduce the workload of subsequent lathe machining. Finally, reaming and finishing produce the final forging. By optimizing the processing technology and combining it with a special punch and die design, the present application can significantly improve the material utilization rate of the bearing inner ring, reduce the time of subsequent processing steps, and thus shorten the manufacturing cycle.

Description

Technical Field

[0001] The present application relates to the technical field of parts forging technology, and in particular to an improved bearing inner ring forging process and processing equipment thereof. Background Art

[0002] Bearing inner rings are key components in railway freight systems, and their manufacturing process directly impacts product performance and cost. In recent years, with the rapid development of the railway freight industry, demand for bearing inner rings has continued to grow, while quality requirements have also become increasingly stringent. To meet the market's urgent need for high-quality, low-cost, and fast-delivery products, companies must continuously optimize their production processes and promote the development of precision and efficiency in the manufacturing industry.

[0003] like Figure 1 Existing bearing inner rings are made of G20CrNi2MoA, a material with a tapered working surface and two end faces, one large and one small. The larger end face has a stepped inner hole, while the smaller end face has a thin wall. Therefore, direct forging is not easy to achieve. Traditionally, bearing inner ring machining involves directly forming the ring into a ring shape and then cutting it. This process is inefficient and utilizes little raw material, significantly increasing product manufacturing cycle time and production costs. Therefore, simplifying the machining process for bearing inner rings, improving efficiency, and improving raw material utilization have become pressing technical challenges in the industry. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present application provides an improved bearing inner ring forging process and processing equipment.

[0005] In a first aspect, the present application provides an improved bearing inner ring forging process, which adopts the following technical solutions:

[0006] An improved bearing inner ring forging process includes the following steps:

[0007] Step 1: Prepare the blank. Select a cylindrical blank and ensure that the shape and size of the blank meet the requirements.

[0008] Step 2: upsetting, heating the blank to the plastic temperature, and then upsetting the blank so that the middle section of the blank bulges outwards to a certain arc;

[0009] Step 3: Back-extrusion molding: Use the die and punch to back-extrude the upset blank. Through the constraints of the punch and the die, the side wall of the blank is L-shaped, a blind hole is formed in the middle of the blank, and a cone with a certain angle and depth is formed at the intersection of the blind hole and the top of the blank.

[0010] Step 4: Punching: Punching the blank with a punch to punch through the blind holes on the blank;

[0011] Step 5: After the punching of the blank is completed, the top and conical surface of the blank are extruded to refine the shape of the top and conical surface of the blank to meet the process requirements;

[0012] Step 6: Hole expansion: Place the blank into the hole expansion equipment and use the mandrel to expand the inner hole and conical surface of the blank so that the inner hole and conical surface of the blank meet the process requirements;

[0013] Step 7: Finishing: Finish the entire blank and precisely control the shape and size of each position of the blank to obtain the final forging.

[0014] In a second aspect, the present application provides an improved bearing inner ring forging processing equipment, which adopts the following technical solutions:

[0015] An improved bearing inner ring forging processing equipment comprises a lower template, an upper template and a press, the press is used to drive the upper template to slide in the vertical direction, the lower template is respectively provided with an upsetting station, a reverse extrusion station and a punching station, the upsetting station is provided with a lower upsetting table, the reverse extrusion station is provided with a forming die, the punching station is installed with a punching die, the upper template is respectively provided with an upper upsetting table, a forming punch, a perforating punch and a flat stripper plate, and the upper upsetting table corresponds to the position of the lower upsetting table, the forming punch corresponds to the position of the forming die, the perforating punch and the flat stripper both correspond to the position of the punching die, the flat stripper is horizontally arranged, the bottom end of the flat stripper is provided with a boss, and the side wall of the boss is provided with a certain taper.

[0016] Optionally, the forming mold includes an outer mold and an inner mold, the lower mold plate is provided with a bottom support platform, the top of the bottom support platform is provided with a mounting groove, the outer mold is adapted to the mounting groove, and the outer mold is placed in the mounting groove, the inner mold is passed through the outer mold and adapted to the outer mold, and the inner diameter of the inner mold gradually decreases along the direction approaching the bottom support platform.

[0017] Optionally, a gasket is further provided in the outer mold, and the gasket is provided at the bottom of the inner mold. A center hole is opened on the bottom support platform, and the center hole is connected to the mounting groove. A bottom iron is placed in the center hole, and the bottom iron is passed through the gasket and the inner mold and is adapted to the inner mold.

[0018] Optionally, a forming connection seat is fixedly provided on the upper template, and the forming punch is detachably provided on the forming connection seat.

[0019] Optionally, the forming punch includes a mounting section, a connecting section and a stamping section, the mounting section is fixedly connected to the forming connecting seat, the connecting section is arranged between the mounting section and the stamping section, and a conical connecting surface is provided at the connection between the connecting section and the stamping section for forming a conical surface on the blank, and the diameter of the stamping section gradually decreases in the direction away from the connecting section.

[0020] Optionally, a sliding sleeve is provided on the forming connecting seat, and the sliding sleeve is provided with a crimping portion for abutting the bottom end of the mounting section of the forming punch. A forming unloading plate is fixedly connected below the sliding sleeve, and the forming unloading plate is slidingly sleeved on the forming punch. A unloading spring is provided on the upper template for driving the forming unloading plate to slide away from the upper template.

[0021] Optionally, the bottom end of the punching section is provided with a curved surface, and the intersection of the curved surface and the side wall of the forming punch is provided with an arc chamfer.

[0022] Optionally, a perforated connection seat is fixedly provided on the upper template, and the perforated punch is detachably provided on the perforated connection seat.

[0023] Optionally, the flat high unloading plate is slidably sleeved on the perforated connecting seat, and an adjusting screw is provided on the upper template to limit the sliding of the flat high unloading plate.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. This application can significantly improve the material utilization rate of the bearing inner ring, reduce the time of subsequent processing steps, and thus shorten the manufacturing cycle. Specifically, by upsetting the blank, the middle section of the blank is made to bulge outward with a certain arc, which facilitates the subsequent positioning and deformation of the blank; the blank is subjected to reverse extrusion processing by the punch and die, so that the blank forms a preliminary shape close to the finished product; the blank shape is further refined through punching and flattening steps, which helps to reduce the workload of subsequent lathe processing. Finally, the final forging is obtained through hole expansion and fine processing. The entire process is formed by step-by-step forging, which simplifies the processing steps, improves processing efficiency, and avoids material waste, achieving the goals of high quality, low cost and short delivery time.

[0026] 2. The improved bearing inner ring forging processing equipment of the present application realizes efficient forging processing of the bearing inner ring. Specifically, by setting a roughing station, a back-extrusion station and a punching station, and then through the mutual cooperation between the upper template and the lower template, the deformation process of the blank can be accurately controlled, the processing efficiency can be improved, and the processing steps can be simplified.

[0027] 3. The present application comprises a cap that is slidably mounted on the forming connection seat, and a forming stripper plate that is fixedly mounted below the cap. The forming stripper plate is slidably mounted on the forming punch. When the forming punch is in the process of reverse extrusion of the blank, the elastic stripper plate abuts against the top end of the blank, and the elastic stripper plate slides on the forming punch. When the crimping portion of the cap abuts against the bottom end of the mounting section of the forming punch, the forming stripper plate stops sliding, limiting the top end of the blank, controlling the deformation direction of the top end of the blank, and improving the accuracy of the reverse extrusion deformation of the blank. When the reverse extrusion molding of the blank is completed, the forming punch moves up. At this time, the forming stripper plate presses the top end of the blank under the elastic force of the stripper spring. At the same time, the forming stripper plate and the forming punch slide relative to each other, so that the forming punch and the blank can be separated, thereby improving the convenience of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram used to express the structure of the existing bearing inner ring;

[0029] Figure 2 is a process flow chart of Example 1 of the present application;

[0030] Figure 3 This is a schematic diagram of the structure of the mandrel used in Example 1 of the present application;

[0031] Figure 4 This is a schematic diagram of the overall structure of Example 2 of the present application;

[0032] Figure 5 This is a schematic diagram of the structure of the reverse extrusion station used in Example 2 of the present application;

[0033] Figure 6 This is a schematic diagram of the structure of the forming punch used in Example 2 of the present application;

[0034] Figure 7 This is a schematic diagram of the structure of the punching station used in Example 2 of the present application;

[0035] Figure 8 This is a schematic diagram of the structure of the flat-high unloading plate used in Example 2 of the present application.

[0036] Explanation of reference numerals: 1, lower template; 11, upsetting station; 12, reverse extrusion station; 13, punching station; 14, lower upsetting table; 15, base; 16, forming die; 161, outer die; 162, inner die; 163, gasket; 17, bottom support; 171, bottom iron; 18, punching die; 19, support seat; 2, upper template; 21, upper upsetting table; 22, forming connection seat; 2 3. Forming punch; 231. Mounting section; 232. Connecting section; 233. Stamping section; 234. Conical connecting surface; 235. Arc surface; 24. Cap; 241. Crimping section; 242. Forming unloading plate; 25. Unloading spring; 26. Perforated connecting seat; 27. Perforated punch; 28. Flat unloading plate; 281. Boss; 282. Screw sleeve; 29. ​​Adjusting screw; 3. Press. DETAILED DESCRIPTION

[0037] The following will be combined with the Figure 2 -Attached Figure 8 The technical solutions in the embodiments of the present invention are clearly and completely described. The described embodiments are only possible technical implementations of the present invention and do not constitute a complete set of implementations. Those skilled in the art can combine the embodiments of the present invention to derive other embodiments without inventive work, and such embodiments are also within the scope of protection of the present invention.

[0038] The inventors of this application have discovered that conventional bearing inner ring processing techniques typically involve directly processing the inner ring into a ring shape and then cutting it. This process is inefficient and utilizes little raw material, significantly increasing product manufacturing cycles and production costs. Therefore, this application discloses an improved bearing inner ring forging process and processing equipment, primarily employing the following solutions: Example

[0039] Example 1 of the present application discloses an improved bearing inner ring forging process. Figure 2 and Figure 3 , including the following steps:

[0040] Step 1: Preparing the blank

[0041] The blank is made of 90mm diameter round steel made of G20CrNi2MoA, which is cut by sawing or hot shearing. When cutting the blank, it is necessary to ensure that the shape and size of the blank meet the requirements, and the quality is inspected by testing equipment.

[0042] Step 2: Upsetting

[0043] The blank is heated to the plastic temperature, which is usually 1150℃-1250℃, and then upset to make the middle section of the blank bulge outward with a certain arc, which is convenient for positioning and deformation of the blank in subsequent workstations.

[0044] Step 3: Reverse extrusion

[0045] By setting up a punch and a die, the upset blank is reverse-extruded to deform the blank. At the same time, the constraints of the punch and the die force the blank to flow and deform in a predetermined direction, forming a preliminary shape close to the finished product. After reverse extrusion, the sidewall of the blank is L-shaped, with the top of the blank being the large end face and the bottom being the small end face. A blind hole is formed in the middle of the top of the blank, and the intersection of the blind hole and the top of the blank forms a cone with a certain angle and depth. The depth of the cone is about 15mm and the angle is about 20°.

[0046] Step 4: Punching

[0047] After the blank is reversely extruded, it is punched by a punch, which is inserted into the blind hole in the middle of the blank to punch through the blind hole on the blank.

[0048] Step 5: Leveling

[0049] After the blank is punched, the top and conical surface of the blank are extruded to refine the shape of the top and conical surface so that the top and conical surface of the blank meet the process requirements, which helps to reduce the workload of subsequent turning. After the flattening is completed, the top of the blank is flush, and the final forming angle of the conical surface is between 15°-25°, and the depth is between 13mm-15mm.

[0050] Step 6: Expand the hole

[0051] The blank is placed in the reaming equipment, and the inner hole and conical surface of the blank are rolled and expanded through the mandrel so that the inner hole and conical surface of the blank meet the process requirements; the side wall of the mandrel is provided with a conical end face matching the conical surface, so as to perform contour rolling and expansion on the conical surface. The front end of the mandrel has a taper, the angle is generally between 25°-45°, and the height is between 10mm-20mm. The top end needs to maintain a sharp angle to control the occurrence of defects.

[0052] Step 7: Finishing

[0053] The blank is finished as a whole, and the shape and size of each position of the blank are precisely controlled to obtain the final forging. Finishing includes lathes and grinders. Lathes are used to process the outer and inner diameters of the blank, and grinders are used to process the surface finish of the blank.

[0054] The implementation principle of an improved bearing inner ring forging process in Example 1 of the present application is as follows: by optimizing the processing technology, the material utilization rate of the bearing inner ring is improved, the time of subsequent processing steps is reduced, and thus the manufacturing cycle is shortened. Specifically, by upsetting the blank, the middle section of the blank is made to bulge outward by a certain arc, which facilitates the subsequent positioning and deformation of the blank; the blank is back-extruded by a punch and a die to form a preliminary shape close to the finished product; the blank shape is further refined through punching and flattening steps, which helps to reduce the workload of subsequent lathe processing; finally, the final forging is obtained through hole expansion and fine machining. The entire process is formed by step-by-step forging, which simplifies the processing steps, improves processing efficiency, and avoids material waste, achieving the goals of high quality, low cost, and short delivery time.

[0055] The process after the above optimization and adjustment can be used to process the inner rings of bearings for heavy-duty trucks, increasing the utilization rate of forging materials by 77%, 10% ahead of the industry. Compared with before optimization, each bearing inner ring saves 0.63kg of material, which alone can save the company millions of dollars in raw materials annually.

[0056] Example 2

[0057] Example 2 of the present application discloses an improved bearing inner ring forging processing equipment, referring to Figure 4 , comprising a lower template 1, an upper template 2 and a press 3. The press 3 is used to drive the upper template 2 to slide in the vertical direction. The lower template 1 is respectively provided with an upsetting station 11, a reverse extrusion station 12 and a punching station 13. Specifically, a lower upsetting table 14 is provided at the upsetting station 11 of the lower template 1, and an upper upsetting table 21 is installed on the upper template 2. The upper upsetting table 21 corresponds to the position of the lower upsetting table 14, and the top wall of the lower upsetting table 14 and the bottom wall of the upper upsetting table 21 are both arranged horizontally. The blank is placed on the lower upsetting table 14, and the upper template 2 is driven downward by the press 3, which drives the upper upsetting table 21 downward. The upper upsetting table 21 and the lower upsetting table 14 respectively squeeze the upper and lower ends of the blank, causing the middle section of the blank to bulge outward by a certain arc, thereby completing the upsetting of the blank.

[0058] Reference Figure 4 A base 15 is placed at the upsetting station 11 of the lower template 1. A receiving groove is formed at the top of the base 15. The lower upsetting table 14 fits within the receiving groove and is placed within it. A pad is provided between the lower upsetting table 14 and the bottom wall of the receiving groove. The upper upsetting table 21 is bolted to the upper template 2. This design facilitates maintenance and replacement of the lower upsetting table 14 and the upper upsetting table 21.

[0059] Reference Figure 4 、 5A forming die 16 is provided at the reverse extrusion station 12 of the lower template 1, and a forming connecting seat 22 is fixed to the upper template 2 by bolts. The length direction of the forming connecting seat 22 is vertical, and a forming punch 23 is installed at the bottom end of the forming connecting seat 22. The forming punch 23 is fixed to the forming connecting seat 22 by bolts. The position of the forming punch 23 corresponds to that of the forming die 16, and the length direction of the forming punch 23 is vertical.

[0060] Reference Figure 5 Specifically, the forming die 16 includes an outer die 161 and an inner die 162. A bottom support 17 is provided at the reverse extrusion station 12 of the lower die plate 1. A mounting groove is provided at the top of the bottom support 17. The outer die 161 plate is adapted to the mounting groove and placed in the mounting groove. The inner die 162 is adapted to the outer die 161. A protrusion is provided on the side wall of the inner die 162. A groove is provided at the bottom end of the outer die 161 along the axial direction of the outer die 161. The groove is adapted to the protrusion. The inner diameter of the inner die 162 plate gradually decreases as it approaches the bottom support 17. This design facilitates the maintenance and replacement of the forming die 16. At the same time, the combined design of the outer die 161 and the inner die 162 can achieve precise constraint on the deformation direction of the blank, improve the forming accuracy of the forging, and simplify subsequent processing steps.

[0061] Reference Figure 5 A gasket 163 is also provided in the outer die 161. The gasket 163 is provided at the bottom of the inner die 162 and abuts against the lower side wall of the mounting groove. A center hole is provided on the bottom support 17, which is connected to the mounting groove. A bottom iron 171 is placed in the center hole. The bottom iron 171 is passed through the gasket 163 and the inner die 162 and is adapted to the inner die 162. A pad is also provided below the bottom iron 171. The arrangement of the gasket 163 and the bottom iron 171 can effectively support the inner die 162 and evenly distribute the pressure, preventing damage to the die due to excessive pressure during the reverse extrusion process. In addition, the design of the bottom iron 171 adapted to the forming die 16 ensures that the flow direction and forming effect of the metal material in the reverse extrusion process are more precisely controllable, further improving the quality and consistency of the forgings.

[0062] Reference Figure 5 、 6Specifically, the forming punch 23 includes a mounting section 231, a connecting section 232 and a stamping section 233. The mounting section 231 abuts against the bottom end of the forming connecting seat 22 and is fixed to the forming connecting seat 22. The connecting section 232 is arranged between the mounting section 231 and the stamping section 233. A conical connecting surface 234 is provided at the connection between the connecting section 232 and the stamping section 233. The diameter of the stamping section 233 gradually decreases in the direction away from the connecting section 232; the conical connecting surface 234 between the connecting section 232 and the stamping section 233 can form a conical surface with a certain angle and depth on the blank, thereby improving the shape accuracy of the forging; the design of the gradually decreasing diameter of the stamping section 233 helps the metal material to flow evenly during the forming process and reduce the occurrence of defects.

[0063] Reference Figure 6 The bottom end of the punch section 233 is provided with a curved surface 235, and the intersection of the curved surface 235 and the side wall of the forming punch 23 is provided with a curved chamfer. The curved surface 235 provided at the bottom end of the punch section 233 can smooth the inner hole edge of the blank during the reverse extrusion process, reducing stress concentration, thereby improving the forming quality of the forging. The curved chamfer provided at the intersection of the curved surface 235 and the side wall of the forming punch 23 further optimizes the flow properties of the metal material, avoids cracks or defects at sharp corners, and ensures the uniformity and integrity of the internal structure of the forging.

[0064] Reference Figure 5 , a sliding sleeve is provided on the forming connection seat 22, and a crimping portion 241 is provided in the cap 24. The crimping portion 241 is integrally formed with the cap 24 and is located below the mounting section 231 of the forming punch 23. A forming stripper plate 242 is fixedly connected to the cap 24 below by bolts. The forming stripper plate 242 is slidingly sleeved on the connecting section 232 of the forming punch 23 and is adapted to the connecting section 232 of the forming punch 23. A discharge spring 25 is provided on the upper template 2. The discharge spring 25 are connected to the cap 24 and the upper template 2 respectively; when the forming punch 23 is in the process of reverse extrusion of the blank, the elastic stripper plate abuts against the top of the blank, and the elastic stripper plate slides on the forming punch 23, compressing the stripper spring 25. When the crimping portion 241 of the cap 24 abuts against the bottom end of the mounting section 231 of the forming punch 23, the forming stripper plate 242 stops sliding, limiting the top of the blank, controlling the deformation direction of the top of the blank, and improving the accuracy of the reverse extrusion deformation of the blank. When the reverse extrusion of the blank is completed, the forming punch 23 moves upward. At this time, the forming stripper plate 242 presses the top of the blank under the elastic force of the stripper spring 25. At the same time, the forming stripper plate 242 and the forming punch 23 slide relative to each other, so that the forming punch 23 can be separated from the blank, improving the convenience of use.

[0065] Reference Figure 7The punching station 13 of the lower template 1 is equipped with a punching die 18, and the upper template 2 is fixed with a punching connection seat 26 by bolts. The length direction of the punching connection seat 26 is vertical. The bottom end of the punching connection seat 26 is fixed with a punching punch 27 by bolts. The length direction of the punching punch 27 is vertical, and the punching punch 27 and the flat discharge plate 28 both correspond to the position of the punching die 18. Specifically, the punching station 13 of the lower template 1 is provided with a support seat 19. The punching die 18 is fixed to the top of the support seat 19 by bolts. The middle part of the punching die 18 is provided with a through hole. The support seat 19 is provided with a discharge hole. The discharge hole corresponds to the position of the through hole and is connected to each other. The blank is placed in the punching die, and the upper template 2 is driven downward by the press 3, which drives the punching punch 27 downward, so that the punching punch 27 is inserted into the blind hole in the middle of the blank, and the blind hole on the blank is punched through.

[0066] Reference Figure 7 、 8 , a flat stripper plate 28 is also slidably provided on the perforated connecting seat 26, and the flat stripper plate 28 is horizontally arranged. A boss 281 is provided at the bottom end of the flat stripper plate 28, and the side wall of the boss 281 is provided with a certain taper. An adjusting screw 29 is rotatably provided on the upper template 2, and the length direction of the adjusting screw is vertical. A screw sleeve 282 is fixedly provided on the flat stripper plate 28, and the adjusting screw is passed through the screw sleeve 282 and is threadedly engaged with the screw sleeve 282; after the perforating punch 27 completes the punching of the blank, the upper template 2 continues to slide down so that the flat stripper plate 28 abuts against the top of the blank, and the shape of the top of the blank is refined by the flat stripper plate 28, and the shape of the conical surface of the blank is refined by the boss 281, so that the top and conical surface of the blank meet the process requirements. The flat stripper plate 28 is slidably mounted on the perforated connecting seat 26 and its sliding is limited by adjusting the screw rod 29, thereby achieving precise control of the position of the flat stripper plate 28 and improving the forming accuracy of the forging.

[0067] The implementation principle of the improved bearing inner ring forging processing equipment of Example 2 of the present application is as follows: by arranging an upsetting station 11, a reverse extrusion station 12, and a punching station 13 on the lower template 1, the deformation process of the blank is precisely controlled, the processing efficiency is improved, and the processing steps are simplified. Specifically, the lower upsetting table 14 at the upsetting station 11 cooperates with the upper upsetting table 21 to cause the middle section of the blank to bulge outward by a certain arc, which is convenient for subsequent positioning and deformation; the forming die 16 at the reverse extrusion station 12 cooperates with the forming punch 23 to make the side wall of the blank L-shaped, forming a blind hole in the middle, and forming a conical surface with a certain angle and depth at the intersection of the blind hole and the top, effectively improving material utilization and forming accuracy; the perforation die and perforation punch 27 at the punching station 13 cooperate to punch through the blind hole, further refining the shape of the blank. The flat high unloading plate 28 is horizontally arranged and has a tapered boss 281 at the bottom end, which can squeeze the top of the blank after punching, refine the top and tapered surface shape, and ensure that the process requirements are met.

[0068] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. An improved bearing inner ring forging process, which uses an improved bearing inner ring forging equipment, characterized by: Equipment includes: A lower template (1), an upper template (2) and a press (3), wherein the press (3) is used to drive the upper template (2) to slide in a vertical direction, and the lower template (1) is respectively provided with an upsetting station (11), a reverse extrusion station (12) and a punching station (13), wherein the upsetting station (11) is provided with a lower upsetting table (14), the reverse extrusion station (12) is provided with a forming die (16), and the punching station (13) is provided with a punching die (18), and the upper template (2) is respectively provided with an upper upsetting table (2 1), a forming punch (23), a perforating punch (27) and a flat stripper plate (28), wherein the upper upsetting platform (21) corresponds to the position of the lower upsetting platform (14), the forming punch (23) corresponds to the position of the forming die (16), the perforating punch (27) and the flat stripper plate (28) both correspond to the position of the punching die (18), the flat stripper plate (28) is arranged horizontally, and a boss (281) is arranged at the bottom end of the flat stripper plate (28), and the side wall of the boss (281) is arranged with a certain taper; A forming connection seat (22) is fixedly provided on the upper template (2), and the forming punch (23) is detachably provided on the forming connection seat (22); The forming punch (23) comprises a mounting section (231), a connecting section (232) and a punching section (233); the mounting section (231) is fixedly connected to the forming connecting seat (22); the connecting section (232) is arranged between the mounting section (231) and the punching section (233); a conical connecting surface (234) is provided at the connection between the connecting section (232) and the punching section (233) for forming a conical surface on the blank; the diameter of the punching section (233) gradually decreases in a direction away from the connecting section (232); A cap (24) is slidably sleeved on the forming connection seat (22), and the cap (24) is provided with a crimping portion (241) for abutting against the bottom end of the mounting section (231) of the forming punch (23). A forming stripper plate (242) is fixedly connected below the cap (24), and the forming stripper plate (242) is slidably sleeved on the forming punch (23). A stripper spring (25) is provided on the upper template (2) for driving the forming stripper plate (242) to slide in a direction away from the upper template (2); The bottom end of the punching section (233) is provided with a curved surface (235), and the intersection of the curved surface (235) and the side wall of the forming punch (23) is provided with an arc chamfer; A perforated connection seat (26) is also fixedly provided on the upper template (2), and the perforated punch (27) is detachably provided on the perforated connection seat (26); The flat high discharge plate (28) is slidably sleeved on the perforated connecting seat (26), and an adjusting screw rod (29) is provided on the upper template (2) for limiting the sliding of the flat high discharge plate (28); The process includes the following steps: Step 1: Prepare the blank. Select a cylindrical blank and ensure that the shape and size of the blank meet the requirements. Step 2: upsetting, heating the blank to the plastic temperature, and then upsetting the blank so that the middle section of the blank bulges outwards to a certain arc; Step 3: Back-extrusion molding: Use the die and punch to back-extrude the upset blank. Through the constraints of the punch and the die, the side wall of the blank is L-shaped, a blind hole is formed in the middle of the blank, and a cone with a certain angle and depth is formed at the intersection of the blind hole and the top of the blank. Step 4: Punching: Punching the blank with a punch to punch through the blind holes on the blank; Step 5: After the punching of the blank is completed, the top and conical surface of the blank are extruded to refine the shape of the top and conical surface of the blank to meet the process requirements; Step 6: Hole expansion: Place the blank into the hole expansion equipment and use the mandrel to expand the inner hole and conical surface of the blank so that the inner hole and conical surface of the blank meet the process requirements; Step 7: Finishing: Finish the entire blank and precisely control the shape and size of each position of the blank to obtain the final forging.

2. The improved bearing inner ring forging process according to claim 1, characterized in that: The molding die (16) comprises an outer die (161) and an inner die (162); a bottom support platform (17) is provided on the lower die plate (1); a mounting groove is provided at the top end of the bottom support platform (17); the outer die (161) is adapted to the mounting groove, and the outer die (161) is placed in the mounting groove; the inner die (162) is passed through the outer die (161) and adapted to the outer die (161); the inner diameter of the inner die (162) gradually decreases in a direction approaching the bottom support platform (17).

3. The improved bearing inner ring forging process according to claim 2, characterized in that: A washer (163) is further provided in the outer mold (161), and the washer (163) is provided at the bottom of the inner mold (162). A center hole is provided on the bottom support platform (17), and the center hole is connected to the mounting groove. A bottom iron (171) is placed in the center hole, and the bottom iron (171) is passed through the washer (163) and the inner mold (162), and is adapted to the inner mold (162).

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