A rocker arm type forging production die set and a using method thereof

Abstract

The present application belongs to the field of rocker arm forging process, and relates to a die set for rocker arm type forgings and a use method thereof. The die set comprises an upper die seat, a lower die seat, a guide assembly, a clamping assembly and an ejection assembly arranged between the upper die seat and the lower die seat. The guide assembly comprises three guide columns and guide sleeves matched with the guide columns, two of the guide columns are arranged at the rear of the die set, and the other guide column is arranged at the right side of the operating position of the die set to form a triangular support guide structure. The clamping assembly comprises a front inclined surface pressing structure and a side inclined surface pressing structure, the front inclined surface pressing structure and the side inclined surface pressing structure press the rocker arm module on the lower die seat through hexagonal head bolts. The ejection assembly comprises a U-shaped ejector rod ejection structure, which realizes synchronous ejection through U-shaped lever linkage upper die transition ejector rod and lower die transition ejector rod. The guide, clamping and ejection form a precise cooperative closed loop, and the impact resistance and long-term operation stability of the die set under complex forging load are improved.

Description

Technical Field

[0001] This invention belongs to the field of rocker arm forging technology, and relates to a mold frame for producing rocker arm forgings and its usage method. Background Technology

[0002] Rocker arm forgings (see) Figure 2 Rocker arm forgings typically have irregular shapes, complex structures such as thin webs, high ribs, and raised platforms, and are mostly unmachined surfaces with significant variations in cross-section along the longitudinal direction. Because rocker arm forgings play a crucial role in transmitting force and motion within mechanical systems, they require high strength, toughness, and fatigue resistance. Standard die-casting designs are used for production, but rocker arm forgings have very high requirements for appearance, misalignment, thickness, and residual straight edges. The appearance must be free of any cracks, folds, oxide scale pits, or incomplete filling; misalignment requirements are ≤0.5mm; thickness tolerance is +1.2 / -0.5mm; residual flash is ≤0.8mm. Existing standard die-casting designs struggle to meet all the drawing requirements, leading to poor forging quality stability and frequent failures in continuous forging production. Summary of the Invention

[0003] The purpose of this invention is to provide a mold frame and method for using rocker arm forgings, so as to solve the technical problem that the existing technology is difficult to meet the various drawing requirements, resulting in poor forging quality stability and many failures in continuous forging production.

[0004] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, this application discloses a mold frame for producing rocker arm forgings, comprising: an upper mold base, a lower mold base, and a guide assembly, a clamping assembly, and an ejection assembly disposed between the upper mold base and the lower mold base; The guiding assembly includes three guide posts and guide sleeves that cooperate with the guide posts, wherein two guide posts are located at the rear of the mold frame and the other guide post is located on the right side of the mold frame operating position to form a triangular support guiding structure; The clamping assembly includes a front inclined clamping structure and a side inclined clamping structure, which clamp the rocker arm module onto the lower mold base using hexagonal head bolts; The ejection assembly includes a U-shaped ejector rod ejection structure, which achieves synchronous ejection by linking the upper mold transition ejector rod and the lower mold transition ejector rod through a U-shaped lever.

[0005] Optionally, a rearward adjustment plate is provided directly behind the inner wall of the cavity of the lower mold base, and a lateral adjustment plate is provided on the right side of the inner wall of the cavity of the lower mold base.

[0006] Optionally, the upper mold base is provided with a circular keyway for positioning, and the positioning accuracy of the circular keyway is 0.03mm.

[0007] Optionally, the U-shaped ejector structure includes a U-shaped lever, a bearing seat, a lever shaft, and a U-shaped lever pressure plate. The U-shaped lever is mounted on the bearing seat via the lever shaft. One end of the U-shaped lever corresponds to the lower mold transition ejector, and the other end corresponds to the upper mold transition ejector via the U-shaped lever pressure plate.

[0008] Optionally, the three guide pillars and the guide sleeve have a small fit clearance and high positional accuracy, which can ensure that the misalignment of the rocker arm forging is ≤0.5mm.

[0009] Optionally, the mold frame is a two-station mold frame, and the mold frame is provided with a pre-forging cavity and a final forging cavity.

[0010] Optionally, the front inclined surface pressing structure is achieved by a front pressing block, and the side inclined surface pressing structure is achieved by a side pressing block. The front pressing block and the side pressing block are respectively locked by hexagonal head bolts.

[0011] Secondly, this application discloses a method of using a mold frame for producing rocker arm forgings as described in any one of the above claims, characterized in that it includes a misalignment adjustment step, an ejection step, and a forging step; In the aforementioned error adjustment step, the front-to-back and left-to-right error of the rocker arm forging is controlled by adjusting the fit clearance of the side inclined clamping structure within the mold frame. In the ejection step, the upper and lower mold frames are driven to move synchronously through the U-shaped ejector rod ejection structure to achieve demolding of the rocker arm forging; In the forging step, the rocker arm module is pressed into the mold frame, and the forming force is distributed through multiple stations inside the mold frame for forging.

[0012] Optionally, a rearward adjustment plate is provided directly behind the inner wall of the cavity of the lower mold base, and a lateral adjustment plate is provided on the right side of the inner wall of the cavity of the lower mold base; the U-shaped ejector rod ejection structure includes a U-shaped lever, a shaft seat, a lever shaft, and a U-shaped lever pressure plate; In the aforementioned error adjustment step, the rearward adjustment plate directly behind the inner wall of the lower mold base cavity and the lateral adjustment plate on the right side are ground to achieve front-to-back and left-to-right error adjustment, with the error adjustment accuracy controlled within the range of 0.05mm. In the ejection step, the upper and lower mold frames are ejected synchronously by driving the U-shaped lever to rotate around the lever axis and by driving the upper mold transition ejector and the lower mold transition ejector to move through the U-shaped lever pressure plate.

[0013] Optionally, the mold frame is a two-station mold frame, and the mold frame is provided with a pre-forging cavity and a final forging cavity; in the forging step, the rocker arm forging is placed in the pre-forging cavity and the final forging cavity of the mold frame in sequence for pre-forging and final forging; the pre-forging cavity is used to bear part of the final forging force, so that the impact force during final forging is less than the impact force of single-station forging.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This application effectively improves the stress balance of the die frame during the forging process by adopting a triangular support and guiding structure with three guide pillars, overcoming the defects of guide eccentricity and rapid wear on one side caused by the traditional double guide pillar structure, thereby ensuring the error accuracy of the rocker arm forging. At the same time, by using the front and side inclined surface clamping structure fastened by hexagonal head bolts to replace the traditional wedge clamping method, the problem of easy loosening and difficult disassembly of the original structure is completely solved, and the positioning firmness of the rocker arm module under high pressure and high frequency impact is significantly enhanced. On this basis, with the use of a U-shaped lever linkage upper and lower die synchronous ejection structure, the limitation of conventional die frames with only lower ejection is broken, fundamentally eliminating the phenomenon of forgings "sticking to the die" and jamming during demolding after high-tonnage forming. The three components do not work in isolation. The precise guidance of the three guide pillars greatly suppresses the lateral displacement that the module may experience when subjected to inclined plane clamping force and forging impact, effectively protecting the guide pillars and guide sleeves from excessive lateral shear force. This not only improves the accuracy of finished product error but also extends the service life of the guiding mechanism. Meanwhile, the U-shaped linkage ejection structure, while completing reliable demolding, also smoothly transmits its force through levers, reducing local fatigue damage to the bottom of the mold base. This allows the guiding, clamping, and ejection systems to form a precise synergistic closed loop, significantly improving the overall impact rigidity and long-term operational stability of the mold base under complex forging loads, laying a solid foundation for the high-quality and efficient production of rocker arm forgings.

[0015] Furthermore, a rearward adjustment plate and a lateral adjustment plate are added to the rear and right sides of the cavity inner wall of the lower mold base, respectively, providing a structural basis for the mold frame to independently fine-tune the positioning position of the rocker arm module in both front-to-back and left-to-right directions. When the forging misalignment does not meet the requirements, the relative position of the module can be changed by precisely grinding the thickness of the corresponding adjustment plate, completely abandoning the traditional method of adjusting the misalignment by roughly padding with wedges using scrap saw blades, and effectively controlling the misalignment adjustment accuracy within 0.05mm. This refined design works closely with the front and side inclined high-pressure fastening structure. The adjusted reference surface can be quickly and firmly held by the inclined locking force applied by the hexagonal head bolts, avoiding the hidden danger of module loosening under high-pressure operation due to adjustment gaps or shims. At the same time, the reliable positioning boundary formed around the module further utilizes the motion stability brought by the precision guidance of the three guide pillars. The two work together to ensure the extremely high repeatability of the rocker arm module position under each forging impact, thereby effectively ensuring the consistency of batch production of rocker arm forgings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is an assembly drawing of the mold frame structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of an existing rocker arm forging structure; Figure 3 This is a main sectional view of the mold frame according to an embodiment of the present invention; Figure 4 This is a side sectional view of the mold frame according to an embodiment of the present invention; Figure 5 This is a top view of the mold frame according to an embodiment of the present invention.

[0018] Wherein: 1-Upper mold base; 2-Side pressure block; 3-First spring washer; 4-First internal hexagonal head screw; 5-Side adjusting plate; 6-Lower mold base; 7-U-shaped lever; 8-Hexagonal nut; 9-Second spring washer; 10-T-slot bolt; 11-Second internal hexagonal head screw; 12-Third spring washer; 13-Positioning key; 14-Upper mold transition ejector rod; 15-Spring; 16-Guide post; 17-Guide sleeve; 18-Rear pressure plate; 19-Fourth spring washer; 20-Third internal hexagonal head screw; 21-Rear adjusting plate; 22-Hexagonal head bolt; 23-Front pressure block; 24-Lower mold transition ejector rod; 25-Equipment lower mold transition ejector rod; 26- U-shaped lever pressure plate; 27-fifth spring washer; 28-fourth internal hexagonal head screw; 29-shaft seat; 30-lever shaft; 31-fifth internal hexagonal head screw. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0024] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0025] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 , Figures 3-5 This application discloses a mold frame for producing rocker arm forgings, including: an upper mold base 1, a lower mold base 6, and a guide assembly, a clamping assembly, and an ejection assembly disposed between the upper mold base 1 and the lower mold base 6; The guide assembly includes three guide posts 16 and guide sleeves 17 that cooperate with the guide posts 16, wherein two guide posts 16 are located at the rear of the mold frame and the other guide post 16 is located on the right side of the mold frame operating position to form a triangular support guide structure. The clamping assembly includes a front inclined clamping structure and a side inclined clamping structure. The front inclined clamping structure and the side inclined clamping structure clamp the rocker arm module onto the lower mold base 6 by means of hexagonal head bolts 22. The ejection assembly includes a U-shaped ejector rod ejection structure, which achieves synchronous ejection by linking the upper mold transition ejector rod 14 and the lower mold transition ejector rod 24 through a U-shaped lever 7.

[0026] The triangular support structure formed by three guide pillars effectively improves the stress condition during the movement of the mold frame, overcoming the defects of traditional double guide pillar structures that easily lead to guide eccentricity and rapid wear on one side. It significantly improves the closing guide accuracy of the upper and lower molds, thereby effectively ensuring the error requirements of rocker arm forgings. With the front and side inclined surface clamping structure locked by hexagonal head bolts, this invention replaces the traditional wedge structure that is prone to loosening. Under long-term high-frequency and high-pressure forging conditions, it ensures the positioning firmness of the rocker arm module and completely solves the problems of easy loosening and difficult disassembly and assembly of the original structure. At the same time, the ejection structure that realizes the synchronous linkage of the upper and lower molds by using U-shaped levers breaks through the limitation of conventional structures that only have a lower ejection structure. It effectively solves the industry pain point that forgings are prone to sticking to the mold after large-tonnage forming and cannot be easily demolded, ensuring the smoothness and reliability of the demolding action.

[0027] In some embodiments, a rearward adjustment plate 21 is provided directly behind the inner wall of the cavity of the lower die holder 6, and a lateral adjustment plate 5 is provided on the right side of the inner wall of the cavity of the lower die holder 6. The rearward adjustment plate 21 and the lateral adjustment plate 5 independently provide precise fine-tuning references in the front-back and left-right directions, respectively, improving the forging misalignment control accuracy to 0.05mm, effectively avoiding the instability of the reference caused by traditional padding methods, and ensuring stable positioning and batch production consistency after adjustment.

[0028] In some embodiments, the upper mold base 1 is provided with a circular keyway for positioning, and the positioning accuracy of the circular keyway is 0.03mm. The circular keyway provides a high-precision positioning reference of 0.03mm for the upper mold base, ensuring precise alignment of the upper and lower molds; this precise positioning, combined with the three-guide-pillar guiding structure, fundamentally eliminates the lateral shear force of the guide pillars caused by initial assembly deviations, effectively preventing guide pillar jamming and abnormal wear, and jointly ensuring the long-term guiding accuracy and operational stability of the mold frame as a whole.

[0029] In some embodiments, the U-shaped ejector structure includes a U-shaped lever 7, a bearing seat 29, a lever shaft 30, and a U-shaped lever pressure plate 26. The U-shaped lever 7 is mounted on the bearing seat 29 via the lever shaft 30. One end of the U-shaped lever 7 corresponds to the lower die transition ejector 24, and the other end corresponds to the upper die transition ejector 14 via the U-shaped lever pressure plate 26. The lever shaft 30 enables single-drive bidirectional linkage, with one end directly driving the lower die transition ejector and the other end synchronously driving the upper die transition ejector via the U-shaped lever pressure plate 26, achieving synchronous demolding of the upper and lower dies. This fundamentally eliminates the phenomenon of forgings sticking to the upper die and jamming. Its lever linkage design ensures uniform force distribution and a compact structure, requiring only one ejection action to effectively balance the smooth ejection of both pre-forging and final forging steps, significantly improving the demolding reliability and cycle stability of the die set under continuous high-frequency production.

[0030] In some embodiments, the three guide pillars 16 and the guide sleeve 17 have a small fit clearance and high positional accuracy, which can ensure that the misalignment of the rocker arm forging is ≤0.5mm. Their stable guidance and inclined surface pressing work together to effectively suppress lateral displacement under forging impact and ensure long-term high-precision alignment of the mold frame.

[0031] In some embodiments, the die set is a two-station die set, with a pre-forging cavity and a final forging cavity inside. The pre-forging cavity effectively distributes the final forging load, significantly reducing the final forging impact force, thereby greatly reducing die wear, ejection force, and lateral force on the forging, effectively reducing surface scratches and improving thickness uniformity; its low-impact forming characteristics, together with the precision guiding and stable clamping structure of the die set, form a synergistic effect, significantly improving the batch quality stability of the rocker arm forgings and the overall service life of the die set.

[0032] In some embodiments, the front inclined clamping structure is implemented by a front clamping block 23, and the side inclined clamping structure is implemented by a side clamping block 2. The front clamping block 23 and the side clamping block 2 are respectively locked by hexagonal head bolts 22. The front clamping block 23 and the side clamping block 2 efficiently convert the axial locking force of the hexagonal head bolts 22 into inclined clamping force, firmly locking the rocker arm module and completely eliminating the defect of easy loosening of traditional wedge structures. Its stable locking boundary and the precision guiding height of the three guide pillars work together to effectively suppress lateral movement under impact conditions, and comprehensively ensure the durability of the overall centering accuracy of the mold frame and the stability of long-term service.

[0033] This application also discloses a method for using a mold frame for producing rocker arm forgings, including a misalignment adjustment step, an ejection step, and a forging step; In the aforementioned error adjustment step, the front-to-back and left-to-right error of the rocker arm forging is controlled by adjusting the fit clearance of the side inclined clamping structure within the mold frame. In the ejection step, the upper and lower mold frames are driven to move synchronously through the U-shaped ejector rod ejection structure to achieve demolding of the rocker arm forging; In the forging step, the rocker arm module is pressed into the mold frame, and the forming force is distributed through multiple stations inside the mold frame for forging.

[0034] This method achieves precise control of misalignment by adjusting the side-sloping clamping structure, eliminating the drawbacks of traditional padding adjustments that are prone to loosening and have poor precision. The U-shaped linkage ejection structure completely avoids the sticking and jamming problems caused by unidirectional demolding. Combined with multi-station distribution of forming force, it effectively reduces the final forging impact and mold wear. These steps work in close coordination; the stable positioning benchmark established by misalignment adjustment ensures the consistency of precision in multi-station continuous forging, while smooth synchronous demolding ensures the smooth connection of multi-station processing cycles. This comprehensively improves the forming quality of the rocker arm forgings and the service stability of the mold base from an operational perspective.

[0035] In some embodiments, a rearward adjustment plate 21 is provided directly behind the inner wall of the cavity of the lower mold base 6, and a lateral adjustment plate 5 is provided on the right side of the inner wall of the cavity of the lower mold base 6; the U-shaped ejector rod ejection structure includes a U-shaped lever 7, a shaft seat 29, a lever shaft 30, and a U-shaped lever pressure plate 26. In the aforementioned error adjustment step, the rearward adjustment plate 21 directly behind the inner wall of the lower mold base 6 cavity and the lateral adjustment plate 5 on the right side are ground to achieve front-to-back and left-to-right error adjustment, and the error adjustment accuracy is controlled within the range of 0.05mm. In the ejection step, the U-shaped lever 7 is driven to rotate around the lever shaft 30, and the U-shaped lever pressure plate 26 drives the upper mold transition ejector 14 and the lower mold transition ejector 24 to move, completing the synchronous ejection of the upper and lower mold frames. Through grinding and fine-tuning of the rear and side adjustment plates, the error control accuracy is improved to 0.05mm, completely overcoming the reference drift defect caused by traditional padding adjustment. Simultaneously, the linkage structure of the U-shaped lever, lever shaft, and pressure plate transforms the single driving force into the synchronous and stable ejection of the upper and lower molds, effectively avoiding mold sticking and jamming. The synergistic effect of these two mechanisms creates a virtuous cycle between the high-precision positioning of the rocker arm module and the force transmission during demolding, ensuring not only the repeatability of errors during multi-station forging but also optimizing the stress state of the forging during demolding, thereby comprehensively improving the production stability and product consistency of the mold frame under long-term high-frequency impact.

[0036] In some embodiments, the die set is a two-station die set, with a pre-forging cavity and a final forging cavity inside. During the forging process, the rocker arm forging is sequentially placed in the pre-forging cavity and the final forging cavity of the die set for pre-forging and final forging. The pre-forging cavity bears part of the final forging force, making the impact force during final forging less than that of single-station forging. The pre-forging cavity effectively distributes the final forging load, significantly reducing the final forging impact force, thereby greatly reducing die wear, ejection force, and lateral force on the forging, effectively reducing surface scratches and improving thickness uniformity. Its low-impact forming characteristics synergize well with the precision guiding and stable clamping structure of the die set, significantly improving the batch quality stability of the rocker arm forging and the overall service life of the die set.

[0037] Example 1 This invention combines the structural characteristics of rocker arm forgings and redesigns a special mold frame structure, breaking through the existing conventional mold frame structure and making it better suited for the production of rocker arm forgings.

[0038] 1) The current mold frame adopts a double guide post and guide sleeve structure at the rear of the mold frame. The guide is eccentric, which is prone to uneven force, resulting in faster wear on one side, eccentricity between the upper and lower molds, and difficulty in ensuring the correct mold alignment of the forging.

[0039] Technical means: The present invention adopts a three-guide post and guide sleeve structure. Two guide posts are located behind the mold frame and one guide post is located on the right side of the operating position, forming a stable triangular support. The gap between the guide posts and guide sleeves is small and the position accuracy requirement is high, which can ensure that the misalignment of rocker arm forgings is ≤0.5mm.

[0040] 2) The current mold frame adopts a wedge clamping module structure. This structure is difficult to disassemble and assemble, is prone to loosening during use, has poor precision, and has poor quality stability for forgings with high precision requirements.

[0041] Technical means: The present invention adopts the front inclined surface pressing and the side inclined surface pressing of the upper and lower mold frames, and the rocker arm module is reliably pressed in front, behind and to the left and right by hexagonal head high-strength bolts. For forgings with high precision requirements, the quality stability is high.

[0042] 3) The current mold frame adopts a wedge clamping module structure. When adjusting the forging misalignment, it is only possible to roughly use a scrap saw blade to manually grind it and clamp it in the gap of the wedge to adjust the left and right misalignment. The front and back misalignment cannot be adjusted.

[0043] Technical means: This invention adopts a front inclined surface clamping and side inclined surface clamping method for the upper and lower mold frames. Lateral adjustment plates are designed on the rear side and right inner wall of the lower mold frame cavity. When the forging misalignment does not meet the requirements, the lateral adjustment plates can be ground to control the accuracy within 0.05mm, and the rocker arm forging misalignment can be adjusted back and forth and left and right.

[0044] 4) The existing mold base has a bottom ejection structure but no top ejection structure. When the rocker arm forging is produced, the forming force is large at one time, and the bottom ejection is not smooth. In addition, the existing mold base has no top ejection structure, and the sticking to the upper mold occurs frequently.

[0045] Technical means: The upper and lower mold frames of this invention adopt a U-shaped ejector structure. This new ejection method, with a single U-shaped ejector, can also serve as the ejection device for both the pre-forging and final forging steps. The lower ejection amount is 25mm, and the upper ejection amount is 13mm. This ensures smooth ejection for both the pre-forging and final forging steps, eliminating situations where the material cannot be ejected or sticks to the mold.

[0046] 5) The current mold frame uses two circular keyways for positioning of the upper mold, while the lower mold is not fixed and is only secured by four T-bolts. This easily leads to deviation during production, resulting in rapid wear of the guide pillars and guide sleeves and poor guiding accuracy.

[0047] Technical means: The present invention uses two circular keyways on each of the upper mold base for positioning, which requires high precision and effectively ensures the smooth guidance of the three guide pillars and guide sleeves, with a precision requirement of 0.03mm.

[0048] 6) The current mold frame is a single-station forging system, and the forming of the forging is controlled by adjusting the impact force. Single-station forging leads to mold wear and failure, short lifespan, poor forging precision, large ejection force, large lateral force on the forging, severe surface damage, poor thickness stability, and reduced forging stability.

[0049] Technical means: The new invention adopts a two-station pre-forging method, in which the pre-forging cavity bears part of the force of the final forging. During the final forging, the force is smaller, the mold wear is smaller, the ejection force is smaller, the lateral force of the forging is smaller, the surface damage is smaller, the thickness uniformity is better, and the stability of the forging is improved.

[0050] This invention breaks through the conventional die set design concept. First, it adopts a three-guide-post and guide-sleeve design instead of the conventional two-guide-post and guide-sleeve design. The new design is based on a stable triangular support guiding mode, with small gaps between the guide posts and guide sleeves and high positional accuracy requirements, ensuring the error tolerance requirements of precision forgings. Second, it eliminates the current wedge-clamping module structure, which is difficult to disassemble and assemble, prone to loosening during use, and has poor precision, resulting in poor quality stability for forgings with high precision requirements. The new design uses front and side inclined clamping methods for the upper and lower die sets, and designs lateral adjustment plates at the rear and right inner wall of the lower die set cavity. When the forging error does not meet the requirements, the lateral adjustment plates can be ground to control the precision within 0.05mm, adjusting the rocker arm forging error in all directions. Third, the current die set is a bottom-ejection structure without an upper ejection structure. During the production of rocker arm forgings, the one-time forming force is large, and the lower die ejection is not smooth. In addition, the current die set has no upper ejection structure, and the sticking to the upper die is frequent. The newly designed upper and lower die sets adopt a U-shaped ejector pin structure. This new ejection method, with a single U-shaped ejector pin, can also serve as the ejection device for both the pre-forging and final forging steps. This ensures smooth ejection for both steps, eliminating issues such as failure to eject or sticking to the die. The new die set design results in high forging precision and fast die changeover, laying the foundation for subsequent precision forging.

[0051] Example 2 The three-guide-pillar mold base forms a stable triangular support guiding pattern. The designed lateral adjustment plate has an accuracy controllable within 0.05mm, allowing for adjustment of the rocker arm forging misalignment in all directions. The upper and lower mold bases are designed with a U-shaped ejector structure. This new ejection method, using the U-shaped ejector, can also function as a two-step ejection device for pre-forging and final forging. The two-station pre-forging and final forging method uses the pre-forging cavity to bear part of the final forging force. During final forging, the force is smaller, resulting in less mold wear, less ejection force, less lateral force on the forging, fewer surface scratches, better thickness uniformity, and improved forging stability. This effectively meets the production requirements of rocker arm forgings.

[0052] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A mold frame for producing rocker arm forgings, characterized in that, include: It includes an upper mold base (1), a lower mold base (6), and a guide assembly, a clamping assembly, and an ejection assembly disposed between the upper mold base (1) and the lower mold base (6); The guide assembly includes three guide posts (16) and a guide sleeve (17) that cooperates with the guide posts (16), wherein two guide posts (16) are located at the rear of the mold frame and the other guide post (16) is located on the right side of the mold frame operating position to form a triangular support guide structure; The clamping assembly includes a front inclined surface clamping structure and a side inclined surface clamping structure. The front inclined surface clamping structure and the side inclined surface clamping structure clamp the rocker arm module onto the lower mold base (6) by means of hexagonal head bolts (22). The ejection assembly includes a U-shaped ejector rod ejection structure. The U-shaped ejector rod ejection structure achieves synchronous ejection by linking the upper mold transition ejector rod (14) and the lower mold transition ejector rod (24) through a U-shaped lever (7).

2. The mold frame for producing rocker arm forgings according to claim 1, characterized in that, The lower mold base (6) has a rearward adjustment plate (21) directly behind the cavity inner wall and a side adjustment plate (5) on the right side of the cavity inner wall.

3. The mold frame for producing rocker arm forgings according to claim 1, characterized in that, The upper mold base (1) is provided with a circular keyway for positioning, and the positioning accuracy of the circular keyway is 0.03mm.

4. The mold frame for producing rocker arm forgings according to claim 1, characterized in that, The U-shaped ejector structure includes a U-shaped lever (7), a bearing seat (29), a lever shaft (30), and a U-shaped lever pressure plate (26). The U-shaped lever (7) is mounted on the bearing seat (29) via the lever shaft (30). One end of the U-shaped lever (7) corresponds to the lower mold transition ejector (24), and the other end corresponds to the upper mold transition ejector (14) via the U-shaped lever pressure plate (26).

5. A mold frame for producing rocker arm forgings according to claim 1, characterized in that, The three guide pillars (16) and the guide sleeve (17) have a small fit clearance and high positional accuracy, which can ensure that the error of the rocker arm forging is ≤0.5mm.

6. The mold frame for producing rocker arm forgings according to claim 1, characterized in that, The mold frame is a two-station mold frame, and the mold frame is provided with a pre-forging cavity and a final forging cavity.

7. A mold frame for producing rocker arm forgings according to claim 1, characterized in that, The front inclined surface pressing structure is achieved by the front pressing block (23), and the side inclined surface pressing structure is achieved by the side pressing block (2). The front pressing block (23) and the side pressing block (2) are respectively locked by hexagonal head bolts (22).

8. A method of using a mold frame for producing rocker arm forgings as described in any one of claims 1 to 7, characterized in that, This includes the error adjustment step, the ejection step, and the forging step; In the aforementioned error adjustment step, the front-to-back and left-to-right error of the rocker arm forging is controlled by adjusting the fit clearance of the side inclined clamping structure within the mold frame. In the ejection step, the upper and lower mold frames are driven to move synchronously through the U-shaped ejector rod ejection structure to achieve demolding of the rocker arm forging; In the forging step, the rocker arm module is pressed into the mold frame, and the forming force is distributed through multiple stations inside the mold frame for forging.

9. The method of using a mold frame for producing rocker arm forgings according to claim 8, characterized in that, The lower mold base (6) has a rearward adjustment plate (21) located directly behind the cavity inner wall, and a side adjustment plate (5) located on the right side of the cavity inner wall; the U-shaped ejector structure includes a U-shaped lever (7), a shaft seat (29), a lever shaft (30), and a U-shaped lever pressure plate (26). In the aforementioned error adjustment step, the rearward adjustment plate (21) directly behind the inner wall of the cavity of the lower mold base (6) and the lateral adjustment plate (5) on the right side are ground to achieve front-back and left-right error adjustment, and the error adjustment accuracy is controlled within the range of 0.05mm. In the ejection step, the U-shaped lever (7) is driven to rotate around the lever axis (30), and the upper mold transition ejector (14) and lower mold transition ejector (24) are moved in conjunction with the U-shaped lever pressure plate (26) to complete the synchronous ejection of the upper and lower mold frames.

10. The method of using a mold frame for producing rocker arm forgings according to claim 8, characterized in that, The mold frame is a two-station mold frame, with a pre-forging cavity and a final forging cavity inside. In the forging step, the rocker arm forging is placed in the pre-forging cavity and the final forging cavity of the mold frame in sequence for pre-forging and final forging. The pre-forging cavity is used to bear part of the final forging force, so that the impact force during final forging is less than the impact force of single-station forging.

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