Cold heading device of automobile hub adapter sleeve

Abstract

The utility model relates to a cold heading device of an automobile hub adapter sleeve. The cold heading device comprises a cutting mechanism, an ejection mechanism, a conveying mechanism and six dies. The six dies comprise a first upsetting die used for conducting primary shaping on an initial blank and conducting rounding on the lower end, a second upsetting die used for conducting shaping and finishing on the upper end of the overturned first blank through rounding, and a third upsetting die used for conducting extruding and stretching on the upper end of the overturned second blank to form a small-diameter rod part. The four-upsetting die is used for pre-upsetting the lower end of the third blank overturned to the in-situ state to form an upper cylinder and a lower outer hexagonal cylinder; the five-upsetting die is used for upsetting the cylinder of the middle section of the fourth blank to form a large-diameter disc and forming a concave hole in the upper end of the small-diameter rod part of the upper section of the fourth blank; and the six-upsetting die is used for deepening the concave hole of the small-diameter rod part of the upper section of the fifth blank to form a hexagonal inner hole and extruding and stretching the whole small-diameter rod part. By adopting the technical scheme, the production efficiency is improved, materials are saved, and the cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical technology, specifically relating to a cold heading device for an automotive wheel hub adapter sleeve. Background Technology

[0002] The car wheel hub is connected to the car steering mechanism. During the wheel hub assembly process, adapter tools are required. The wheel hub adapter sleeve tightening and locking mechanism can maintain a tight state under various working conditions to ensure driving safety.

[0003] The automotive wheel hub adapter sleeve has a large central disc section with an internal hexagonal hole on one end and an external hexagonal hole on the other. The significant difference in the hexagonal shape allows for flexible rotation at smaller positions on the wheel hub, serving as a tightening and locking mechanism. The part has a complex machining structure, and the original cold heading process cannot directly form the internal hexagonal hole. Subsequent machining is required to achieve the corresponding dimensional requirements. The machining wastes materials, consumes time, and results in low production efficiency and high costs. Utility Model Content

[0004] In summary, to overcome the shortcomings of the prior art, this utility model provides a cold heading device for an automotive wheel hub adapter sleeve.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a cold forging device for an automotive wheel hub adapter sleeve, comprising a cutting mechanism, an ejection mechanism, a conveying mechanism, and six molds, wherein the cutting mechanism cuts the blank, the ejection mechanism lifts the blank, and the conveying mechanism moves between the ejection mechanism and the six molds to feed material; the six molds include: a first forging mold for initially shaping the initial blank and shaping and trimming the lower end by rounding the corners; a second forging mold for shaping and trimming the upper end of the flipped first blank by rounding the corners; a third forging mold for extruding and stretching the upper end of the second blank, which is still in a flipped state, to form a small-diameter rod; and a third for pre-forging the lower end of the third blank, which has been flipped back to its original position, to form an upper cylindrical lower part. The six molds include a four-upsetting mold for an external hexagonal prism, a five-upsetting mold for upsetting the cylindrical section of the fourth blank into a large-diameter disk and forming a cavity at the upper end of the small-diameter rod of the upper section, and a six-upsetting mold for deepening the cavity of the small-diameter rod of the upper section of the fifth blank to form a hexagonal inner hole and for extruding and stretching the entire small-diameter rod. Each mold includes a lower mold and an upper mold. The lower mold includes a lower mold shell, a lower mold core, a lower mold punch, a lower mold lock nut, and a lower mold pad. The lower mold core is located inside the lower mold shell and has a lower mold cavity. The lower mold pad is located below the lower mold core. The lower mold lock nut is connected to the lower mold shell to fix the lower mold pad and the lower mold core. The upper mold includes an upper mold shell, an upper mold pad, and an upper mold punch. The upper mold pad is located inside the upper mold shell.

[0006] By adopting the above technical solution, large-diameter materials are extruded into small-diameter materials and rapidly cold-forged to form hexagonal inner holes, improving production efficiency. Compared with the hot stamping process of heating the material head until it is red-hot, this method saves materials, reduces costs, and minimizes machining waste, achieving the effect of rapid cold-forging of parts without tearing marks in the inner holes. During the cold-forging process, the metal material undergoes plastic deformation in a cold state, refining its internal structure and making the grains finer. This microstructure gives the cold-forged parts high mechanical strength, hardness, and corrosion resistance. It is highly efficient, and mass production can be achieved simply by using molds on a cold heading machine. It is easy to operate, requiring only simple equipment operation and monitoring by workers. The outer hexagon is formed first, and then the hexagonal hole is stretched in six steps. The outer hexagon is formed first and can serve as a "skeleton" to support the parts and resist deformation during the subsequent large disc upsetting and inner hexagonal hole forming. The multi-step forming process transfers the intermediate material to the central convex part to form a full shape, which is especially suitable for safety components such as wheel hub adapter sleeves that need to withstand torque. The metal flow is gradually controlled from the outside to the inside to avoid internal stress concentration.

[0007] This utility model further comprises: the main mold cavity of the first upsetting mold includes a first lower forming cavity for initially shaping the initial blank and rounding the lower end of the initial blank; the main mold cavity of the second upsetting mold has the same shape as the main mold cavity of the first upsetting mold, and the main mold cavity of the second upsetting mold includes a second lower forming cavity for rounding the upper end of the first blank after it has been turned over; the lower die punch of the second upsetting mold passes through the lower die pad of the second upsetting mold and extends into the main mold cavity of the second upsetting mold to flatten the upper end surface of the first blank after it has been turned over; the upper die punch of the second upsetting mold... The die punch extends into the main mold cavity of the second upsetting die to flatten the lower end face of the first blank after it has been flipped. The main mold cavity of the third upsetting die includes a third lower receiving cavity for accommodating the cylinder of the second blank, which is still in the flipped state, and a third lower forming cavity for forming the small-diameter rod. The third lower receiving cavity is rounded at one end corresponding to the third lower forming cavity. The inner diameter of the third lower receiving cavity is larger than the inner diameter of the third lower forming cavity. The upper die punch of the third upsetting die extends into the upper end of the third lower receiving cavity to flatten the lower end face of the cylinder of the second blank, which is still in the flipped state.

[0008] By adopting the above technical solution and employing a step-by-step, progressive process, the metal flow is ensured to be controllable. The first and second upsetting dies round the corners of the blank to improve material density. The initial blank's concave ends are smoothed through arc deformation after flipping. The first upsetting die forms rounded corners at the lower end of the blank, avoiding stress concentration at sharp corners. The second upsetting die uses the same cavity shape as the first upsetting die, reducing the complexity of die manufacturing and replacement, and lowering production costs. The lower die punch flattens the upper end face, and the upper die punch flattens the lower end face; this two-way action ensures the parallelism of the blank's rear end face after flipping, avoiding forming deviations caused by tilting, improving cold upsetting accuracy, and directly enhancing the dimensional consistency of the wheel hub sleeve. The third lower receiving cavity has a larger inner diameter, shaped like the cylinder of the blank. Providing a buffer space, the rounded corners guide the metal to flow smoothly into the third lower forming cavity to form the small-diameter rod. This design avoids folding or tearing caused by sudden deformation, ensuring no tear marks in the inner hole. The first, second, and third upsetting mold structures of this application achieve high precision, low stress, and controllable metal flow in the initial stage through rounded corner shaping, punch coordination, and partitioned cavity design. This not only improves the quality of parts (such as fatigue strength and concentricity) but also reduces production costs and defect rates, fully demonstrating the core advantages of cold upsetting technology. Compared with existing technologies, the structure of this application is more adaptable to the complex needs of automotive wheel hub adapter sleeves, laying a solid foundation for subsequent stations (such as external hexagonal and large disc forming), and ensuring the robustness and efficiency of the entire production process.

[0009] The present invention further comprises: the chamfer of the first lower molding cavity is a1, 95°≤a1≤105°; the chamfer of the second lower molding cavity is a2, a2=a1; the chamfer of the third lower receiving cavity is a3, 115°≤a3≤125°; the inner diameter of the third lower receiving cavity is D3; and the inner diameter of the third lower molding cavity is d3, 0.66D3≤d3≤0.75D3.

[0010] By adopting the above technical solutions, the chamfer a1 of the first lower forming cavity of the first upsetting die is close to but slightly larger than a right angle. This obtuse angle design makes the deformation of the metal more gentle when the initial blank is rounded at the lower end. Compared with the sharp angle, which may cause the metal flow to change abruptly and the fibers to tear, this angle ensures that the material can smoothly and continuously fill the corners of the cavity, effectively reducing internal stress concentration from the first step and providing higher fatigue strength for the part to withstand alternating loads in the future. The apex angle a2 of the second upsetting die is consistent with a1, ensuring that when the blank is flipped and the upper end is shaped, the mechanical conditions experienced are consistent with the first shaping. This symmetrical design ensures the uniformity of the geometric features and material density at both ends of the blank, providing a crucial foundation for ensuring the concentricity and overall symmetry of the part in subsequent steps, avoiding eccentricity or warping caused by asymmetrical forming. In the third upsetting process, The blank needs to be extruded and stretched from a larger cylindrical part to form a small-diameter rod. The chamfer a3 at the entrance of the third lower receiving cavity is set to a large angle of 115° to 125°, forming a wide and open guide slope. This angle can effectively "guide" the metal of the main body of the blank to the relatively narrow third lower forming cavity, significantly reducing the risk of turbulence or folding of the metal when the flow direction changes abruptly. The ratio of d3 (inner diameter of the third lower forming cavity) to D3 (inner diameter of the third lower receiving cavity) is strictly limited to between 0.66 and 0.75, which means that the section reduction rate of each stamping is controlled within an ideal range. This ratio ensures that the metal can achieve sufficient work hardening to improve strength in one deformation, while avoiding the problems of internal and external cracks or excessive forming force that may be caused by excessive deformation. At the same time, it significantly extends the service life of the mold and reduces production costs.

[0011] This utility model further comprises: the main mold cavity of the four-upsetting mold includes a fourth lower receiving cavity for the cylinder of the middle section of the flipped third blank and a fourth lower forming cavity for the lower end of the flipped third blank to be initially formed into an external hexagonal prism. The upper mold shell of the four-upsetting mold is provided with an upper mold core corresponding to one end of the fourth lower receiving cavity. The upper mold core of the four-upsetting mold includes a fourth upper receiving cavity for accommodating the small-diameter rod of the flipped third blank. The inner diameter of the fourth upper receiving cavity is adapted to the inner diameter of the third lower forming cavity. The inner diameter of the fourth upper receiving cavity is smaller than the inner diameter of the fourth lower forming cavity. The inner diameter of the fourth lower receiving cavity is larger than the inner diameter of the fourth lower forming cavity. The connection between the fourth lower receiving cavity and the fourth lower forming cavity is set in a flared shape with a larger upper part and a smaller lower part.

[0012] By adopting the above technical solution, the three- and four-stage upsetting dies gradually form the small-diameter rod and the outer hexagon. The workpiece is flipped again between the third and fourth stages to prevent the third blank from being top-heavy during material transfer, ensuring that the small-diameter rod is not deformed by collision. The cavity of the four-stage upsetting die is clearly divided into a lower fourth receiving cavity (containing the middle cylindrical section), a lower fourth forming cavity (for preliminary forming of the lower outer hexagon), and an upper fourth receiving cavity (containing the small-diameter rod). This zoned design applies the most suitable forming force to different parts of the blank within a single stroke. The lower fourth receiving cavity provides stable support and positioning for the middle cylindrical section of the blank, preventing buckling during extrusion. Simultaneously, the lower fourth forming cavity pre-extrudes the lower end of the blank into an outer hexagonal prism. This functional separation ensures concentrated force and precise dimensions during the forming of the outer hexagon. The fourth upper receiving cavity in the upper die core has an inner diameter that perfectly matches the small-diameter rod formed in the previous station (three upsetting), playing a role in precise positioning and clamping. This ensures the verticality and stability of the entire blank during the stamping process and provides a reliable axial reference for the precise forming of the outer hexagon. The connection between the fourth lower receiving cavity and the fourth lower forming cavity adopts a flared opening that is larger at the top and smaller at the bottom, forming a smooth, gradually narrowing guide channel. When the metal below the blank flows to the fourth lower forming cavity (hexagonal cavity) with a smaller cross section under the action of the main die cavity, the flared opening structure avoids the sudden truncation and overlap of the metal flow lines that may be caused by a 90-degree right-angle turn. Folding would seriously weaken the mechanical strength of the part, ensuring the continuity of the metal material and improving the final high fatigue strength and reliability of the part.

[0013] The present invention further comprises: the included angle of the flared mouth is a4, 35°≤a4≤45°, the inner diameter of the fourth lower receiving cavity is D4, and the maximum inner diameter of the fourth lower forming cavity is d4, 0.85D4≤d4≤0.91D4.

[0014] By adopting the above technical solution, the angle range provided provides an extremely smooth and gradual strain gradient, which smoothly "guides" and "stretches" the metal material into the hexagonal cavity, thereby ensuring the continuity of the material at the microscopic level, fundamentally preventing folding, and improving the final high fatigue strength and reliability of the parts; the reduction of area is controlled within the ideal range, taking into account both forming quality and mold life.

[0015] This utility model further comprises: the main mold cavity of the five-upsetting mold includes an upper forming cavity for upsetting the cylindrical section of the fourth blank into a disc, a middle forming cavity for further forming the hexagonal prism at the lower end of the fourth blank, and a lower movable cavity for accommodating the lower die punch of the five-upsetting mold; the upper mold shell of the five-upsetting mold is provided with an upper die core corresponding to one end of the upper forming cavity; the upper die core of the five-upsetting mold includes a fifth upper forming cavity for upsetting the cylindrical section of the fourth blank into a disc, a fifth upper receiving cavity for accommodating the small-diameter rod portion of the fourth blank, and... The upper movable cavity is used to accommodate the upper die punch of the five-upsetting die. The fifth upper die forming cavity is arranged opposite to the upper forming cavity and has the same inner diameter. The lower end of the upper die punch of the five-upsetting die is provided with a frustum protrusion for forming a recess at the top of the small-diameter rod of the fourth blank. The frustum protrusion is larger at the top and smaller at the bottom. The frustum protrusion of the upper die punch of the five-upsetting die extends into the fifth upper accommodating cavity. The upper end of the lower die punch of the five-upsetting die is provided with a positioning protrusion for forming a positioning hole at the lower end of the outer hexagonal prism of the fourth blank. The positioning protrusion of the lower die punch of the five-upsetting die extends into the middle forming cavity.

[0016] By adopting the above technical solution, the fifth upper die forming cavity and the upper section forming cavity of the lower die are set opposite each other and have the same inner diameter. When the upper die moves downward, the cylinder in the middle section of the fourth blank is symmetrically squeezed into this cavity in both directions. Symmetrical force avoids uneven material flow or flash during the upsetting process, ensuring that the large disc formed by upsetting has a dense structure, clear outline, and accurate dimensions. Compared with traditional unidirectional upsetting, the disc end face formed by this structure has higher flatness. The truncated cone protrusion (larger at the top and smaller at the bottom) at the lower end of the upper die punch will pre-press a cavity at the top of the small diameter rod during the stamping process. By pre-forming the cavity (five upsetting) and then deepening the forming (six upsetting), the metal flow is stable, avoiding tearing or folding that may occur in a single forming. The positioning protrusion at the upper end of the lower die punch forms a positioning hole at the lower end of the outer hexagonal column. It will become the reference for the precise guidance of the inner hexagonal punch in the next step, ensuring high concentricity of the inner and outer hexagonal columns. The cavity division of the five upsetting die is clear. The upper forming cavity is responsible for the upsetting of the disc, the middle forming cavity for finishing the outer hexagon, the lower and upper movable cavities provide space for the upper and lower punches, and the fifth upper receiving cavity is used to receive and position the small-diameter rod. This allows the three key steps of disc upsetting, outer hexagon finishing, and inner hexagon cavity pre-forming to be completed simultaneously in one stroke, greatly shortening the production cycle, improving efficiency, avoiding the cumulative errors that may be caused by multiple positioning, ensuring the relative positional accuracy between various features, and ensuring the stability and accuracy of complex deformation processes. At this station, the outer hexagon is further finished and shaped in the middle forming cavity of the lower die, making its size and shape more perfect. Before the final inner hexagon forming, the part already has a precise external reference and prepared internal material. This creates an unparalleled advantage for the six-upsetting die to punch out the inner hexagon hole in one go with high quality, fundamentally ensuring the high concentricity of the inner and outer hexagons and the high quality of the inner hole.

[0017] The present invention further includes the following features: all six inner corners of the middle section molding cavity are provided with rounded corner transitions, and the connection between the upper section molding cavity and the middle section molding cavity is also provided with rounded corner transitions.

[0018] By adopting the above technical solution, the six inner corners of the middle forming cavity (i.e., the outer hexagon forming area) and the connection between the upper and lower cavities are filled with rounded corners. This can evenly distribute the force to a curved surface area, thereby greatly eliminating stress peaks, effectively avoiding local fractures, significantly enhancing the durability of the mold, and reducing mold wear and replacement costs during production. The rounded corner transitions within the cavity provide a smooth guiding ramp for metal flow, allowing the material to smoothly and continuously fill every corner of the cavity, thus forming high-quality outer hexagons with clear edges, full shapes, and no defects. The rounded corner transitions within the mold allow the metal to deform along a smooth curve during the forming process, thereby avoiding stress concentration points caused by flow line interruptions. It also significantly improves the fatigue strength and overall toughness of the final part. For safety components such as automotive wheel hub adapter sleeves that need to withstand repeated torsional loads, this greatly improves the reliability and service life of the product.

[0019] The present invention further comprises: the inner diameter of the fourth lower receiving cavity is D4, and the inner diameter of the upper forming cavity is D5, wherein 1.1D4≤D5≤1.2D4.

[0020] By adopting the above technical solution, one of the core tasks of the five-stage upsetting die is to upset the cylindrical section of the fourth blank into a large-diameter disk. D5 is designed to be 10% to 20% larger than D4, providing the necessary and sufficient space for this upsetting process. This ensures that enough metal material can completely fill the cavity defined by D5 after upsetting, thereby forming a large disk with a clear outline and dense structure. This provides the necessary force-bearing platform for the sleeve. A stable and full disk structure is the cornerstone that supports the hexagonal core without interference during the subsequent internal hexagonal hole forming process.

[0021] The present invention further comprises: the main mold cavity shape of the six-upsetting mold is the same as that of the five-upsetting mold; the upper mold core of the six-upsetting mold includes a sixth upper receiving cavity for accommodating the middle section of the fifth blank and a sixth upper forming cavity for stretching the small-diameter rod of the sixth blank; the upper mold punch of the six-upsetting mold is fitted with a punch sleeve, the outer diameter of the punch sleeve is adapted to the inner diameter of the sixth upper forming cavity; the lower end of the upper mold punch of the six-upsetting mold is provided with a hexagonal protrusion for forming an internal hexagonal hole at the upper end of the small-diameter rod of the sixth blank.

[0022] By adopting the above technical solution, the main cavity shape of the sixth upsetting die is the same as that of the fifth upsetting die. This means that the disk, which has been upset in the middle section of the fifth blank, can be received and positioned by the same cavity structure when it enters the final station. This ensures the consistency of the positioning of the core reference (disk and outer hexagon) of the part from the fifth upsetting to the sixth upsetting, and completely eliminates the cumulative error that may be caused by repositioning. The sixth upper receiving cavity in the upper die core is used to receive and hold the disk, while the sixth upper forming cavity is specifically used for the final extrusion and stretching of the small diameter rod. The partitioned design allows the huge internal hexagon forming force to be evenly distributed to the upper die core and die shell through the disk, avoiding the stretching force being entirely borne by the small diameter rod, which could lead to instability or deformation. At the same time, it ensures that the formed outer hexagon and disk parts are firmly protected and unaffected during the stamping process, thereby focusing all energy on the precise forming of the internal hexagon hole. The upper die punch is fitted with a punch... The outer diameter of the punch sleeve is precisely matched with the inner diameter of the sixth upper forming cavity, forming a high-precision sliding guide pair. When the hexagonal protrusion at the lower end of the upper die punch moves downward to impact the blank, the punch sleeve provides full-range radial support for the upper die punch, effectively preventing the punch from bending or shifting slightly under huge lateral forces, ensuring that the internal hexagonal hole and the external hexagonal prism achieve extremely high concentricity. Under the perfect guidance of the punch sleeve and the stable positioning of the disc, the hexagonal protrusion at the lower end of the upper die punch can exert its maximum efficiency. Using the pre-made cavity of the five-upsetting die, the internal hexagonal hole is precisely and powerfully impacted and formed in one go. Due to the precise guidance and reliable support, the hexagonal protrusion can fully squeeze the metal to all corners of the internal hexagonal cavity, forming an internal hexagonal hole with clear edges, full shape, and accurate dimensions, completely avoiding defects such as hole skew, one-sided wear, or incomplete filling caused by punch offset.

[0023] The embodiments describe specific implementations of this utility model. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the step-by-step cold heading process of the blank in an embodiment of this utility model.

[0025] Figure 2 This is a cross-sectional view of the cold heading device according to an embodiment of the present invention.

[0026] Figure 3 This is a partial structural diagram of the first upsetting mold and the third upsetting mold according to an embodiment of the present utility model.

[0027] Figure 4 for Figure 2 Enlarged view of part A.

[0028] Figure 5 for Figure 2 Enlarged view of part B.

[0029] Figure 6 for Figure 2 Enlarged view of part C.

[0030] Reference numerals: 1. First upsetting mold; 11. Lower mold of the first upsetting mold; 111. Lower mold core of the first upsetting mold; 112. Main mold cavity of the first upsetting mold; 1121. First lower forming cavity; 2. Second upsetting mold; 21. Lower mold of the second upsetting mold; 211. Lower mold core of the second upsetting mold; 212. Main mold cavity of the second upsetting mold; 2121. Second lower forming cavity; 214. Lower die punch of the second upsetting mold; 22. Upper mold of the second upsetting mold; 221. 3. Third upsetting die, 31. Lower die of the third upsetting die, 311. Lower die core of the third upsetting die, 312. Main mold cavity of the third upsetting die, 3121. Third lower receiving cavity, 3122. Third lower forming cavity, 32. Upper die of the third upsetting die, 321. Upper die punch of the third upsetting die; 4. Fourth upsetting die, 41. Lower die of the fourth upsetting die, 411. Lower die core of the fourth upsetting die, 412. Main mold cavity of the fourth upsetting die. 4121. Fourth lower receiving cavity; 4122. Fourth lower forming cavity; 4123. Trumpet opening; 42. Upper mold of the fourth upsetting mold; 421. Upper mold core of the fourth upsetting mold; 4211. Fourth upper receiving cavity; 5. Fifth upsetting mold; 51. Lower mold of the fifth upsetting mold; 511. Lower mold core of the fifth upsetting mold; 512. Main mold cavity of the fifth upsetting mold; 5121. Upper forming cavity; 5122. Middle forming cavity; 5123. Lower movable cavity; 513. 5. Lower die punch of the fifth upsetting die; 5131. Positioning protrusion; 52. Upper die of the fifth upsetting die; 521. Upper die core of the fifth upsetting die; 5211. Fifth upper die forming cavity; 5212. Fifth upper receiving cavity; 5213. Upper movable cavity; 522. Upper die punch of the fifth upsetting die; 5221. Frustum protrusion; 6. Sixth upsetting die; 61. Lower die of the sixth upsetting die; 611. Lower die shell of the sixth upsetting die; 612. Main mold cavity of the sixth upsetting die. 62. Upper die of a six-upsetting die; 621. Upper die core of a six-upsetting die; 6211. Sixth upper receiving cavity; 6212. Sixth upper forming cavity; 622. Upper die punch of a six-upsetting die; 6221. Hexagonal protrusion; 623. Punch sleeve; 71. Initial blank; 72. First blank; 73. Second blank; 74. Third blank; 741. Small diameter rod; 75. Fourth blank; 751. Cylinder; 752. Hexagonal prism; 76. Fifth blank; 761. Recess; 762. Disc; 77. Sixth blank; 771. Internal hexagonal hole. Detailed Implementation

[0031] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

[0032] See appendix Figure 1-6 This embodiment discloses a cold heading device for an automotive wheel hub adapter sleeve, comprising a cutting mechanism, an ejection mechanism, a conveying mechanism, and six molds. The cutting mechanism cuts the blank, and the ejection mechanism lifts the blank. The conveying mechanism moves between the ejection mechanism and the six molds to feed material. The six molds include: a first heading mold 1 for initially shaping the initial blank 71 and rounding its lower end; a second heading mold 2 for rounding the upper end of the flipped first blank 72; a third heading mold 3 for extruding and stretching the upper end of the still-flipped second blank 73 to form a small-diameter rod 741; and a fourth heading mold 4 for pre-heading the lower end of the flipped third blank 74 to form an upper cylinder 751 and a lower hexagonal prism 752. A five-stage upsetting die 5 is used to upset the cylinder 751 in the middle section of the fourth blank 75 to form a large-diameter disk 762 and to form a cavity 761 at the upper end of the small-diameter rod 741 in the upper section; and a six-stage upsetting die 6 is used to deepen the cavity 761 of the small-diameter rod 741 in the upper section of the fifth blank 76 to form a hexagonal inner hole and to extrude and stretch the entire small-diameter rod 741. Each of the six dies includes a lower die and an upper die. The lower die includes a lower die shell, a lower die core, a lower die punch, a lower die lock nut, and a lower die pad. The lower die core is located inside the lower die shell and has a lower die cavity. The lower die pad is located below the lower die core. The lower die lock nut is connected to the lower die shell to fix the lower die pad and the lower die core. The upper die includes an upper die shell, an upper die pad, and an upper die punch. The upper die pad is located inside the upper die shell.

[0033] This embodiment further includes the following configuration: the main mold cavity 112 of the first upsetting mold includes a first lower forming cavity 1121 for initially shaping the initial blank 71 and rounding the lower end of the initial blank 71; the main mold cavity 212 of the second upsetting mold has the same shape as the main mold cavity 112 of the first upsetting mold, and the main mold cavity 212 of the second upsetting mold includes a second lower forming cavity 2121 for rounding the upper end of the first blank 72 after it has been flipped; the lower die punch 214 of the second upsetting mold passes through the lower die 21 pad of the second upsetting mold and extends into the main mold cavity 212 of the second upsetting mold to flatten the upper end surface of the first blank 72 after it has been flipped; the upper die punch 221 of the second upsetting mold extends into the second upsetting mold. The main mold cavity 212 of the mold is used to flatten the lower end face of the first blank 72 after it has been flipped. The main mold cavity 312 of the three-upsetting mold includes a third lower receiving cavity 3121 for accommodating the cylinder 751 of the second blank 73 which is still in the flipped state and a third lower forming cavity 3122 for forming the small diameter rod 741. The third lower receiving cavity 3121 is rounded at one end corresponding to the third lower forming cavity 3122. The inner diameter of the third lower receiving cavity 3121 is larger than the inner diameter of the third lower forming cavity 3122. The upper die punch 321 of the three-upsetting mold extends into the upper end of the third lower receiving cavity 3121 to flatten the lower end face of the cylinder 751 of the second blank 73 which is still in the flipped state.

[0034] This embodiment further specifies that: the chamfer of the first lower molding cavity 1121 is a1, 95°≤a1≤105°; the chamfer of the second lower molding cavity 2121 is a2, a2=a1; the chamfer of the third lower receiving cavity 3121 is a3, 115°≤a3≤125°; the inner diameter of the third lower receiving cavity 3121 is D3; and the inner diameter of the third lower molding cavity 3122 is d3, 0.66D3≤d3≤0.75D3.

[0035] In this utility model, the angle of a1 can be 95°, 97°, 100°, 102° and 105°, and a1 is preferably 100°. The angle of a3 can be 115°, 118°, 120°, 122° and 125°, and a3 is preferably 120°. Preferably, 0.69D3≤d3≤0.72D3 is used.

[0036] This embodiment further includes the following configuration: the main mold cavity 412 of the four-bending mold includes a fourth lower receiving cavity 4121 for the cylinder 751 of the middle section of the flipped third blank 74 and a fourth lower forming cavity 4122 for initially forming the lower end of the flipped third blank 74 into an external hexagonal prism 752. The upper mold shell of the four-bending mold is provided with an upper mold core 421 of the four-bending mold at one end corresponding to the fourth lower receiving cavity 4121. The upper mold core 421 of the four-bending mold includes a cavity for accommodating the flipped third blank 74. The fourth upper receiving cavity 4211 of the small diameter rod portion 741 of the three blanks 74 is adapted to the inner diameter of the third lower forming cavity 3122. The inner diameter of the fourth upper receiving cavity 4211 is smaller than the inner diameter of the fourth lower forming cavity 4122, and the inner diameter of the fourth lower receiving cavity 4121 is larger than the inner diameter of the fourth lower forming cavity 4122. The connection between the fourth lower receiving cavity 4121 and the fourth lower forming cavity 4122 is set in the shape of a flared mouth 4123 that is larger at the top and smaller at the bottom.

[0037] In this embodiment, the included angle of the flared opening 4123 is a4, 35°≤a4≤45°, the inner diameter of the fourth lower receiving cavity 4121 is D4, and the maximum inner diameter of the fourth lower forming cavity 4122 is d4, 0.85D4≤d4≤0.91D4.

[0038] In this utility model, the angle of a4 can be 35°, 37°, 40°, 42° and 45°, and a4 is preferably 40°, preferably 0.88D4≤d4≤0.90D4.

[0039] This embodiment further includes: the main mold cavity 512 of the five-upsetting mold includes an upper forming cavity 5121 for upsetting the cylindrical body 751 of the middle section of the fourth blank 75 into a disc 762, a middle forming cavity 5122 for further forming the outer hexagonal prism 752 at the lower end of the fourth blank 75, and a lower movable cavity 5123 for accommodating the lower die punch 513 of the five-upsetting mold. The upper mold shell of the five-upsetting mold 5 has an upper die core 521 at one end corresponding to the upper forming cavity 5121. The upper die core 521 includes a fifth upper forming cavity 5211 for upsetting the cylindrical body 751 of the middle section of the fourth blank 75 into a disc 762, a fifth upper receiving cavity 5212 for accommodating the small-diameter rod portion 741 of the fourth blank 75, and a lower movable cavity 5123 for accommodating the lower die punch 513 of the five-upsetting mold. The upper movable cavity 5213 of the upper die punch 522 of the five-upsetting die is provided. The fifth upper die forming cavity 5211 is arranged opposite to the upper forming cavity 5121 and has the same inner diameter. The lower end of the upper die punch 522 of the five-upsetting die is provided with a frustum protrusion 5221 for forming a recess 761 at the top of the small diameter rod 741 of the fourth blank 75. The frustum protrusion 5221 is larger at the top and smaller at the bottom. The frustum protrusion 5221 of the upper die punch 522 of the five-upsetting die extends into the fifth upper accommodating cavity 5212. The upper end of the lower die punch 513 of the five-upsetting die is provided with a positioning protrusion 5131 for forming a positioning hole at the lower end of the outer hexagonal prism of the lower end of the fourth blank 75. The positioning protrusion 5131 of the lower die punch 513 of the five-upsetting die extends into the middle forming cavity 5122.

[0040] In this embodiment, the six inner corners of the middle section molding cavity 5122 are all provided with rounded corner transitions, and the connection between the upper section molding cavity 5121 and the middle section molding cavity 5122 is also provided with rounded corner transitions.

[0041] In this embodiment, the inner diameter of the fourth lower receiving cavity 4121 is D4, and the inner diameter of the upper forming cavity 5121 is D5, where 1.1D4≤D5≤1.2D4.

[0042] In the technical solution of this utility model, the preferred value is 1.15D4≤D5≤1.17D4.

[0043] This embodiment further specifies that: the main mold cavity 612 of the six-upsetting mold has the same shape as the main mold cavity 512 of the five-upsetting mold; the upper mold core 621 of the six-upsetting mold includes a sixth upper receiving cavity 6211 for accommodating the middle section of the disk 762 of the fifth blank 76 and a sixth upper forming cavity 6212 for stretching the small-diameter rod portion 741 of the sixth blank 77; the upper mold punch 622 of the six-upsetting mold is fitted with a punch sleeve 623, the outer diameter of the punch sleeve 623 being adapted to the inner diameter of the sixth upper forming cavity 6212; the lower end of the upper mold punch 622 of the six-upsetting mold is provided with a hexagonal protrusion 6221 for forming an internal hexagonal hole 771 at the upper end of the small-diameter rod portion 741 of the sixth blank 77.

[0044] The term "between" as used above does not only refer to the location or position, but also to the interaction between different parts. The terms "upper," "middle," and "lower" mentioned above are only relative positions for ease of explanation and do not exclude the possibility of using other terms.

[0045] The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any kind of additional limitation would be contrary to the spirit of this utility model.

Claims

1. A cold heading device for an automotive wheel hub adapter sleeve, characterized in that: The assembly includes a cutting mechanism, an ejection mechanism, a conveying mechanism, and six molds. The cutting mechanism cuts the blank, and the ejection mechanism lifts the blank. The conveying mechanism moves and feeds material between the ejection mechanism and the six molds. The six molds include: a first upsetting mold for initially shaping the initial blank and rounding its lower end; a second upsetting mold for rounding the upper end of the flipped first blank; a third upsetting mold for extruding and stretching the upper end of the still-flipped second blank to form a small-diameter rod; a fourth upsetting mold for pre-upsetting the lower end of the flipped third blank to form an upper cylinder and a lower hexagonal prism; and a fifth upsetting mold for pre-upsetting the middle section of the fourth blank. The five-stage upsetting die is used to upset a cylindrical part to form a large-diameter disc and to create a recess at the upper end of the small-diameter rod section. A six-stage upsetting die is used to deepen the recess in the small-diameter rod section of the fifth blank to form a hexagonal inner hole and to extrude and stretch the entire small-diameter rod section. Each of the six dies includes a lower die and an upper die. The lower die includes a lower die shell, a lower die core, a lower die punch, a lower die lock nut, and a lower die pad. The lower die core is located inside the lower die shell and has a lower die cavity. The lower die pad is located below the lower die core. The lower die lock nut is connected to the lower die shell to fix the lower die pad and the lower die core. The upper die includes an upper die shell, an upper die pad, and an upper die punch. The upper die pad is located inside the upper die shell.

2. The cold heading device for an automotive wheel hub adapter sleeve according to claim 1, characterized in that: The main mold cavity of the first upsetting mold includes a first lower forming cavity for preliminary shaping of the initial blank and rounding the lower end of the initial blank; the main mold cavity of the second upsetting mold has the same shape as the main mold cavity of the first upsetting mold, and the main mold cavity of the second upsetting mold includes a second lower forming cavity for rounding the upper end of the first blank after it has been flipped; the lower die punch of the second upsetting mold passes through the lower die pad of the second upsetting mold and extends into the main mold cavity of the second upsetting mold to flatten the upper end face of the first blank after it has been flipped; the upper die punch of the second upsetting mold extends into the second... The main mold cavity of the upsetting die is used to flatten the lower end face of the first blank after it has been flipped. The main mold cavity of the three upsetting die includes a third lower receiving cavity for accommodating the cylinder of the second blank that is still in the flipped state and a third lower forming cavity for forming the small diameter rod. The third lower receiving cavity is rounded at one end corresponding to the third lower forming cavity. The inner diameter of the third lower receiving cavity is larger than the inner diameter of the third lower forming cavity. The upper die punch of the three upsetting die extends into the upper end of the third lower receiving cavity to flatten the lower end face of the cylinder of the second blank that is still in the flipped state.

3. The cold heading device for an automotive wheel hub adapter sleeve according to claim 2, characterized in that: The chamfer of the first lower molding cavity is a1, 95°≤a1≤105°; the chamfer of the second lower molding cavity is a2, a2=a1; the chamfer of the third lower receiving cavity is a3, 115°≤a3≤125°; the inner diameter of the third lower receiving cavity is D3; the inner diameter of the third lower molding cavity is d3, 0.66D3≤d3≤0.75D3.

4. The cold heading device for an automotive wheel hub adapter sleeve according to claim 1, characterized in that: The main mold cavity of the four-upsetting mold includes a fourth lower receiving cavity for the cylinder of the middle section of the flipped third blank and a fourth lower forming cavity for the lower end of the flipped third blank to be initially formed into an external hexagonal prism. The upper mold shell of the four-upsetting mold is provided with an upper mold core at one end corresponding to the fourth lower receiving cavity. The upper mold core of the four-upsetting mold includes a fourth upper receiving cavity for accommodating the small-diameter rod of the flipped third blank. The inner diameter of the fourth upper receiving cavity is adapted to the inner diameter of the third lower forming cavity. The inner diameter of the fourth upper receiving cavity is smaller than the inner diameter of the fourth lower forming cavity, and the inner diameter of the fourth lower receiving cavity is larger than the inner diameter of the fourth lower forming cavity. The connection between the fourth lower receiving cavity and the fourth lower forming cavity is set in a flared shape with a larger upper part and a smaller lower part.

5. The cold heading device for an automotive wheel hub adapter sleeve according to claim 4, characterized in that: The included angle of the flared opening is a4, 35°≤a4≤45°, the inner diameter of the fourth lower receiving cavity is D4, and the maximum inner diameter of the fourth lower forming cavity is d4, 0.85D4≤d4≤0.91D4.

6. The cold heading device for an automotive wheel hub adapter sleeve according to claim 4, characterized in that: The main mold cavity of the five-upsetting die includes an upper forming cavity for upsetting the cylindrical section of the fourth blank into a disc, a middle forming cavity for further forming the hexagonal prism at the lower end of the fourth blank, and a lower movable cavity for accommodating the lower die punch of the five-upsetting die. The upper die shell of the five-upsetting die has an upper die core at one end corresponding to the upper forming cavity. The upper die core includes a fifth upper forming cavity for upsetting the cylindrical section of the fourth blank into a disc, a fifth upper receiving cavity for accommodating the small-diameter rod portion of the fourth blank, and a cavity for accommodating the five-upsetting die punch. The upper movable cavity of the upper die punch of the mold, the fifth upper die forming cavity is arranged opposite to the upper forming cavity and has the same inner diameter, the lower end of the upper die punch of the fifth upsetting mold is provided with a frustum protrusion for forming a recess at the top of the small diameter rod of the fourth blank, the frustum protrusion is larger at the top and smaller at the bottom, the frustum protrusion of the upper die punch of the fifth upsetting mold extends into the fifth upper receiving cavity, the upper end of the lower die punch of the fifth upsetting mold is provided with a positioning protrusion for forming a positioning hole at the lower end of the outer hexagonal prism of the lower end of the fourth blank, the positioning protrusion of the lower die punch of the fifth upsetting mold extends into the middle forming cavity.

7. The cold heading device for an automotive wheel hub adapter sleeve according to claim 6, characterized in that: The six inner corners of the middle molding cavity are all provided with rounded transitions, and the connection between the upper molding cavity and the middle molding cavity is also provided with rounded transitions.

8. The cold heading device for an automotive wheel hub adapter sleeve according to claim 6, characterized in that: The inner diameter of the fourth lower cavity is D4, and the inner diameter of the upper forming cavity is D5, where 1.1D4≤D5≤1.2D4.

9. The cold heading device for an automotive wheel hub adapter sleeve according to claim 6, characterized in that: The main mold cavity of the six-upsetting mold has the same shape as the main mold cavity of the five-upsetting mold. The upper mold core of the six-upsetting mold includes a sixth upper receiving cavity for accommodating the middle section of the fifth blank and a sixth upper forming cavity for stretching the small-diameter rod of the sixth blank. The upper mold punch of the six-upsetting mold is fitted with a punch sleeve, the outer diameter of which is adapted to the inner diameter of the sixth upper forming cavity. The lower end of the upper mold punch of the six-upsetting mold is provided with a hexagonal protrusion for forming an internal hexagonal hole at the upper end of the small-diameter rod of the sixth blank.

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