Positioning structure and method for middle split mold hub

Abstract

The invention relates to the technical field of automobile hub forging, in particular to a positioning structure and method for a middle split-die hub, the positioning structure comprises a trimming die and a finish forging die which are used for forming the hub, a positioning boss is arranged in a trimming area of the finish forging die, a V-shaped positioning groove is formed in the corresponding position of the trimming die, and the V-shaped positioning groove is matched with the positioning boss. At least four V-shaped positioning grooves are formed in the trimming die, the length of the straight edge of each V-shaped positioning groove is not smaller than 4 mm, and a discharging gap is formed between the positioning boss on the finish forging die and the V-shaped positioning grooves in the trimming die. The flash positioning structure is arranged on the periphery of the trimming die body, a product is effectively prevented from rotating around the axis, meanwhile, the positioning boss and the V-shaped positioning groove between the finish forging die and the trimming die are arranged, an avoiding discharging gap is formed, it is guaranteed that a hot forging piece does not shake in the trimming die, positioning is accurate, trimming consistency can be greatly improved, the defects of over-cutting, convex edges, burrs and the like are overcome, and the product quality is improved. And accurate and stable trimming positioning is integrally realized.

Description

Technical Field

[0001] This invention relates to the field of automotive wheel hub forging technology, and in particular to a positioning structure and method for an intermediate parting mold wheel hub. Background Technology

[0002] In automotive wheel forging, the intermediate die-splitting wheel forging process has become the main method because it can eliminate the edge chamfering process and reduce the amount of subsequent machining. However, the die forging process itself has the problem of eccentricity between the upper and lower dies, which leads to misalignment of the upper and lower dies and uneven wheel edge cutting. At present, the main solution is to control the coaxiality of the product, rely on the inner contour of the final forging die cavity as the cutting edge positioning reference, and even further reduce the positioning gap.

[0003] In the prior art, such as the patent with publication number CN202825350U, a wheel hub mold template processing and positioning fixture is disclosed, including a square base and several pads. The pads are provided on the square base, and several sets of pin holes for positioning the wheel hub mold template are provided on the pads. The distance from the pin hole in each pin hole group to the center of the square base is equal, and the distance from each pin hole group to the center of the square base is different.

[0004] The above structure uses pin holes on the pad for positioning. However, in actual application, it relies on the contour of the final forging for positioning. The positioning accuracy is unstable due to thermal expansion and contraction, and temperature fluctuations cause changes in the positioning gap, resulting in poor edge consistency. Summary of the Invention

[0005] In view of this, the purpose of this invention is to propose a positioning structure and method for an intermediate parting wheel hub, so as to solve the problems of unstable positioning accuracy due to thermal expansion and contraction, and poor consistency of cutting edges caused by temperature fluctuations.

[0006] To achieve the above objectives, the present invention provides a positioning structure and method for an intermediate parting molded wheel hub, including a trimming mold and a final forging mold for forming the wheel hub. The final forging mold has a positioning boss in the flash area, and the trimming mold has a V-shaped positioning groove at the corresponding position. The cutting die is provided with at least four V-shaped positioning grooves, which are evenly distributed along the circumferential direction. The straight side length of the V-shaped positioning groove is not less than 4mm; A material feeding gap is provided between the positioning boss on the final forging die and the V-shaped positioning groove on the trimming die, and the distance between the material feeding gaps is 0.05mm-0.10mm.

[0007] Preferably, the V-angle of the V-shaped positioning groove 8 is 85° to 95°.

[0008] Preferably, the positioning boss 2 has a conical structure, and the height of the positioning boss 2 is 1.2mm-1.8mm.

[0009] Preferably, the positioning boss 2 of the final forging die 7 is provided with a wear-resistant coating 6 on its exterior, and the wear-resistant coating 6 has a thickness of 3μm-5μm.

[0010] Preferably, when the diameter of the wheel hub is less than 300mm, the V angle of the positioning boss 2 is 85°-90°; When the diameter of the wheel hub is between 300mm and 500mm, the V-angle of the positioning boss 2 is 90°-95°; When the diameter of the wheel hub is greater than 500mm, the V angle of the positioning boss 2 is 95°-100°.

[0011] A positioning method for an intermediate parting mold hub, applied to the aforementioned positioning structure of the intermediate parting mold hub, includes the following steps: S101, Final Forging: Pre-form positioning bosses in the flash area of ​​the final forging die, and monitor the final forging temperature within the set range to ensure that the flash thickness is controlled at 2.8-3.2mm, forming the prototype of the flash positioning structure; S102. Forging transfer: After the final forging is completed, take out the hot forging with flash and use the cooling system to reduce the flash temperature to below 500℃. After the dimensions are stable, implement the fixed-point cooling system, focusing on controlling the temperature of the positioning area. After cooling, the temperature is detected and recorded. S103, Edge trimming positioning: The forging is placed into the edge trimming die. The positioning structure on the flash and the corresponding structure on the edge trimming die are precisely matched to form a gap. The actual working gap is calculated based on the temperature data. The laser rangefinder monitors the positioning gap in real time to achieve precise positioning in the circumferential direction. S104. Edge trimming completed: Edge trimming is completed under positioning constraints. After trimming, the wheel hub profile is checked, the trimming quality is analyzed, positioning parameters are adjusted, and positioning accuracy data is recorded to ensure uniform trimming and avoid over-trimming or convex edge phenomena.

[0012] Preferably, in step S102, the cooling system includes compressed air atomization cooling, with the cooling rate controlled at 50-80℃ / s, and the target temperature is reduced from 800℃ to 550℃ in less than 2 seconds; The beneficial effects of this invention are: Four V-shaped positioning grooves are set around the body of the trimming die to form a flash positioning structure. The positioning structure adopts a V-shaped design with a straight edge length of ≥4mm, which effectively prevents the product from rotating around the axis. At the same time, the positioning boss and V-shaped positioning groove between the final forging die and the trimming die are set with a clearance of 0.05mm-0.10mm to avoid material feeding, ensuring that the hot forging does not shake in the trimming die and is accurately positioned. This can greatly improve the consistency of trimming and avoid defects such as over-cutting, protruding edges, and burrs, achieving accurate and stable trimming positioning as a whole. At the same time, by taking advantage of the fact that the flash area cools down rapidly to below 500℃ after final forging and that the temperature changes slowly, the impact of thermal expansion and contraction on positioning accuracy is reduced. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the planar structure of the final forging die of the present invention; Figure 2 This is a schematic diagram of the planar structure of the edge-cutting mold of the present invention; Figure 3 This is a cross-sectional view of the cutting mold of the present invention.

[0015] The markings in the diagram are: 1. Trimming die; 2. Positioning boss; 3. Feeding gap; 6. Wear-resistant coating; 7. Final forging die; 8. V-shaped positioning groove. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0017] like Figure 1 , Figure 2 , Figure 3 As shown, a positioning structure for an intermediate parting molded wheel hub includes a trimming mold 1 and a final forging mold 7 for forming the wheel hub. The flash area of ​​the final forging mold 7 is provided with a positioning boss 2, and the corresponding position of the trimming mold 1 is provided with a V-shaped positioning groove 8. The trimming mold 1 is provided with at least four V-shaped positioning grooves 8, which are evenly distributed along the circumferential direction. The straight side length of the V-shaped positioning groove 8 is not less than 4mm; A material feeding gap 3 is provided between the positioning boss 2 on the final forging die 7 and the V-shaped positioning groove 8 on the trimming die 1. The distance between the material feeding gaps 3 is 0.05mm-0.10mm.

[0018] In this embodiment, four V-shaped positioning grooves 8 are set around the body of the trimming die 1 to form a flash positioning structure. The positioning structure adopts a V-shaped design with a straight edge length ≥4mm, which effectively prevents the product from rotating around the axis. At the same time, the positioning boss 2 and the V-shaped positioning grooves 8 between the final forging die 7 and the trimming die 1 are set with a clearance gap 3 of 0.05mm-0.10mm to ensure that the hot forging does not shake in the trimming die and is accurately positioned, thus achieving accurate and stable trimming positioning as a whole. At the same time, by taking advantage of the fact that the flash area cools down rapidly to below 500℃ after final forging and that the temperature changes slowly, the impact of thermal expansion and contraction on positioning accuracy is reduced.

[0019] As one implementation method, such as Figure 1 , Figure 2 As shown, the V-angle of the V-shaped positioning groove 8 is 85° to 95°.

[0020] In this embodiment, radial positioning and anti-rotation control of the wheel hub are achieved through multiple sets of V-shaped positioning grooves 8, resulting in less wear in the flash area and improved mold service life.

[0021] As one implementation method, such as Figure 1 , Figure 2 As shown, the positioning boss 2 has a tapered structure, and the height of the positioning boss 2 is 1.2mm-1.8mm.

[0022] In this embodiment, the positioning function is transferred from the high-wear parting surface area to the low-wear flash area by using the positioning boss 2, thereby extending the life of the positioning system. In addition, the positioning boss 2 and the V-shaped positioning groove 8 provided between the final forging die 7 and the trimming die 1 prevent the product from rotating around the axis.

[0023] As one implementation method, such as Figure 1 , Figure 2 As shown, the positioning boss 2 of the final forging die 7 is provided with a wear-resistant coating 6 on its outside, and the thickness of the wear-resistant coating 6 is 3μm-5μm.

[0024] In this embodiment, the wear-resistant coating 6 is used to prevent the forging material from being cold-welded or adhered to the boss surface. At the same time, during the forging process, the positioning boss 2 is subjected to frequent friction and impact. The wear-resistant coating 6 reduces the amount of wear per cycle, thereby extending the service life of the mold. Furthermore, the coating on the outside of the positioning boss 2 can effectively reduce the shape distortion and size change caused by wear, ensuring that the contour of the positioning boss 2 remains stable during the cycle.

[0025] As one implementation method, such as Figure 1 , Figure 2 As shown, when the diameter of the wheel hub is less than 300mm, the V angle of the positioning boss 2 is 85°-90°; When the diameter of the wheel hub is between 300mm and 500mm, the V-angle of the positioning boss 2 is 90°-95°; When the diameter of the wheel hub is greater than 500mm, the V angle of the positioning boss 2 is 95°-100°.

[0026] In this implementation method, the wheel hub product drawings are first analyzed to determine the wheel hub diameter, height, and material type. The number of positioning points is determined based on the product dimensions. Then, the V-shaped positioning structure parameters are selected. This method has strong overall applicability, and different positioning structures can be selected for different products.

[0027] This specification also provides an improved method for positioning an intermediate parting wheel hub, comprising the following steps: S101, Final Forging: Pre-form the positioning boss 2 in the flash area of ​​the final forging die 7, and monitor the final forging temperature within the set range to ensure that the flash thickness is controlled at 2.8-3.2mm, forming the prototype of the flash positioning structure. S102. Forging transfer: After the final forging is completed, take out the hot forging with flash and use the cooling system to reduce the flash temperature to below 500℃. After the dimensions are stable, implement the fixed-point cooling system, focusing on controlling the temperature of the positioning area. After cooling, the temperature is detected and recorded. S103, Edge trimming and positioning: The forging is placed into the edge trimming mold 1. The positioning structure on the flash and the corresponding structure on the edge trimming mold 1 are precisely matched to form a gap. The actual working gap is calculated based on the temperature data. The laser rangefinder monitors the positioning gap in real time to achieve precise positioning in the circumferential direction. S104. Edge trimming completed: Edge trimming is completed under positioning constraints. After trimming, the wheel hub profile is checked, the trimming quality is analyzed, positioning parameters are adjusted, and positioning accuracy data is recorded to ensure uniform trimming and avoid over-trimming or convex edge phenomena.

[0028] In step S102, the cooling system includes compressed air atomization cooling, with a cooling rate controlled at 50-80℃ / s, and the target temperature is reduced from 800℃ to 550℃ in less than 2 seconds.

[0029] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.

[0030] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A positioning structure for an intermediate parting molded wheel hub, comprising a trimming mold (1) for forming the wheel hub and a final forging mold (7), characterized in that, The flash area of ​​the final forging die (7) is provided with a positioning boss (2), and the corresponding position of the trimming die (1) is provided with a V-shaped positioning groove (8). The cutting mold (1) is provided with at least four V-shaped positioning grooves (8), which are evenly distributed along the circumferential direction; The straight side length of the V-shaped positioning groove (8) is not less than 4mm; A feeding gap (3) is provided between the positioning boss (2) on the final forging die (7) and the V-shaped positioning groove (8) on the trimming die (1), and the distance between the feeding gaps (3) is 0.05mm-0.10mm.

2. The positioning structure of the intermediate parting wheel hub according to claim 1, characterized in that, The V-angle of the V-shaped positioning groove (8) is 85° to 95°.

3. The positioning structure of the intermediate parting wheel hub according to claim 1, characterized in that, The positioning boss (2) has a conical structure and the height of the positioning boss (2) is 1.2mm-1.8mm.

4. The positioning structure of an intermediate parting wheel hub according to claim 1, characterized in that, The positioning boss (2) of the final forging die (7) is provided with a wear-resistant coating (6) on the outside, and the thickness of the wear-resistant coating (6) is 3μm-5μm.

5. The positioning structure of an intermediate parting wheel hub according to claim 3, characterized in that, When the diameter of the wheel hub is less than 300mm, the V angle of the positioning boss (2) is 85°-90°; when the diameter of the wheel hub is between 300mm and 500mm, the V angle of the positioning boss (2) is 90°-95°; when the diameter of the wheel hub is greater than 500mm, the V angle of the positioning boss (2) is 95°-100°.

6. A method for positioning an intermediate parting wheel hub, applied to the positioning structure of the intermediate parting wheel hub as described in any one of claims 1-5, characterized in that, Includes the following steps: S101, Final forging: Pre-form the positioning boss (2) in the flash area of ​​the final forging mold (7), and monitor the final forging temperature within the set range to ensure that the flash thickness is controlled at 2.8-3.2mm, forming the prototype of the flash positioning structure; S102. Forging transfer: After the final forging is completed, take out the hot forging with flash and use the cooling system to reduce the flash temperature to below 500℃. After the dimensions are stable, implement the fixed-point cooling system, focusing on controlling the temperature of the positioning area. After cooling, the temperature is detected and recorded. S103, Edge positioning: The forging is placed into the edge cutting mold (1). The positioning structure on the flash and the corresponding structure on the edge cutting mold (1) are precisely matched to form a gap. The actual working gap is calculated according to the temperature data. The laser rangefinder monitors the positioning gap in real time to achieve precise positioning in the circumferential direction. S104. Edge trimming completed: Edge trimming is completed under positioning constraints. After trimming, the wheel hub profile is checked, the trimming quality is analyzed, positioning parameters are adjusted, and positioning accuracy data is recorded to ensure uniform trimming and avoid over-trimming or convex edge phenomena.

7. The positioning method for an intermediate parting wheel hub according to claim 6, characterized in that: In step S102, the cooling system includes compressed air atomization cooling, with a cooling rate controlled at 50-80℃ / s, and the target temperature is reduced from 800℃ to 550℃ in less than 2 seconds.

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