Method of cold extrusion of a wheel hub and wheel hub die

Abstract

The present application relates to the technical field of cold extrusion, and relates to a method for cold extrusion processing of a hub and a hub die, the method comprising the following steps: placing forgeable metal material into a first die, cold extruding to obtain a deep-cylindrical rough casting containing a protruding rim shape, the rim diameter of the deep-cylindrical rough casting being greater than the rim diameter; placing the deep-cylindrical rough casting into a second die, cold extruding to obtain a secondary rough casting extruded out of a spoke shape; placing the secondary rough casting into a third die after being turned over by 180 degrees, preliminarily shaping the rim by pressing down the third die, and cold extruding the end part of the rim into a shape by pressing down the third die, to finally obtain a finished hub in the shape of a rim. The present application has the advantages of improving the efficiency of hub production, effectively reducing the production cost, improving the quality of the hub, having higher structural strength, having better comprehensive mechanical properties, and being capable of improving the qualified rate of the product and the material utilization rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cold extrusion, in particular to a method for cold extrusion processing of a hub and a hub die. BACKGROUND

[0002] At present, there are various manufacturing methods for hubs, but the mainstream manufacturing processes mainly include casting, forging and spinning.

[0003] The casting method is to pour alloy solution into a mold by gravity or low pressure, and then complete production through mechanical processing, surface coating and the like. The casting method has the advantages of low cost and high production efficiency, but has the disadvantages of being unable to eliminate defects caused by casting, being prone to bubbles, having low density, rough surface, poor comprehensive mechanical properties and being not environmentally friendly.

[0004] Forging is a processing method for producing a certain shape and size by applying pressure to a metal blank by a forging machine to make it plastically deform, and then spinning out a rim. The commonly used forging production is carried out in a state that the metal is hot, although the reliability of the product is good, but the production environment is high in temperature, high in danger, low in utilization rate of product raw materials, high in material loss, many in process, and high in subsequent processing cost.

[0005] The existing hub generally has a rim smaller than a spoke, so that defects such as inclusion of foreign matters, poor adhesion, folding and cracking are prone to occur in the intersection area. SUMMARY

[0006] The present application solves the technical problems of the existing hub casting process, such as easy production of bubbles, low density, rough surface, poor comprehensive mechanical properties and environmental unfriendliness, and provides a cold extrusion processing method for a hub, which has small environmental pollution, small danger, high utilization rate of product raw materials, small material loss, low subsequent processing cost, and can avoid problems such as position fracture, wrinkle, peeling and inclusion of foreign matters in the step of producing a spoke shape, and the rim is larger than the spoke.

[0007] For the purpose of the present application, the following technical solutions are adopted:

[0008] A method for cold extrusion processing of a hub, comprising the following steps:

[0009] S1, deep cylindrical rough blank forming: a piece of pie-shaped forgeable metal material is put into a first die, the first die extrudes the pie-shaped forgeable metal material by a cold extrusion process to form a deep cylindrical rough blank in a U shape with the opening downward, the upper part of the deep cylindrical rough blank is a spoke, and the lower part of the deep cylindrical rough blank is a rim; and the rim diameter of the deep cylindrical rough blank is larger than the rim diameter of the deep cylindrical rough blank, and finally the deep cylindrical rough blank is taken out from the first die;

[0010] S2, secondary rough forming: the deep cylindrical rough blank is put into the second mold, the second mold extrudes the deep cylindrical rough blank by the cold extrusion process to obtain a secondary rough blank with the shape of a spoke; the spoke center of the secondary rough blank is extruded to form a spoke notch on both the upper and lower sides; and the outer wall of the rim of the secondary rough blank is formed into an extrusion step; the extruded secondary rough blank is taken out from the second mold;

[0011] S3, hub forming: the secondary rough blank is turned over 180° and put into the third mold, the third mold first preliminarily shapes the rim of the secondary rough blank by the cold extrusion process, so that the rim is flared; then the top end of the rim is cold-extruded and bent outward to form a final product hub with the shape of a rim.

[0012] Compared with the prior art, the method extrudes the forgeable metal material through the first mold to obtain a deep cylindrical rough blank containing a protruding rim shape, then extrudes a spoke shape through the second mold, and then extrudes a rim shape through the third mold. The method uses a mold to cold-extrude the raw material to obtain a finished hub throughout the process, which has a very high utilization rate of materials, a high product qualification rate, is safe and environmentally friendly in production at room temperature, and has good consistency and high comprehensive mechanical properties.

[0013] 1. Compared with the casting method, the hub produced by the cold extrusion processing hub method has higher density and significantly improved structural strength; the surface of the hub produced by the casting method is usually rough and needs to be processed again, while the surface of the hub produced by the cold extrusion processing hub method has better surface finish, the surface finish can usually reach more than 0.4, does not need to be processed again, has higher structural strength, and has better quality.

[0014] 2. Since the forging method cannot directly forge a spoke shape, a large amount of raw materials is wasted, the cold extrusion processing hub method can greatly save raw materials, and the cold extrusion processing hub method can also eliminate the step of using processing equipment to mill the spoke shape of the hub blank, which can save equipment cost and labor cost; and the hub produced by the cold extrusion processing hub method does not damage the flow lines of the raw materials, can obtain better structural strength and mechanical properties, and will not have defects such as cracks, pores, folds, or non-metallic inclusions.

[0015] 3. The deep cylindrical rough blank containing a protruding rim shape obtained by extruding the forgeable metal material through the first mold can facilitate the production of a spoke shape and avoid situations such as rim position breakage, wrinkles, peeling, and inclusion of foreign matter in the step of producing a spoke shape, the hub produced by the cold extrusion processing hub method has smoother flow lines, high structural strength, good integrity, and better comprehensive mechanical properties.

[0016] 4. The product of this application has fewer production steps. The wheel hub completed by three-step extrusion only needs a small amount of finishing to complete the process, which can effectively improve production efficiency and save manpower and material resources.

[0017] Preferably, the ratio of the flange diameter to the rim diameter of the deep cylindrical blank is between 1.09 and 1.15. By reasonably setting the flange diameter and rim diameter, the possibility of unreasonable flange flow lines in process two can be effectively reduced, and the overall strength of the finished product can be improved, which has great practical value.

[0018] A cold extrusion wheel hub die includes a first die, a second die, and a third die as described in the cold extrusion wheel hub method. The first die includes a first upper die, a first lower die, a first ejector pin, and a first cavity support. The first cavity support is hollow, and its hollow portion forms a first wheel hub cavity. The first upper die and the first lower die cooperate to simultaneously cold extrude towards the center, obtaining a deep cylindrical blank containing a protruding rim shape. The rim diameter of the deep cylindrical blank is larger than the rim diameter. The first ejector pin then ejects the deep cylindrical blank from the first die. By making the rim diameter of the deep cylindrical blank larger than the rim diameter, issues such as rim breakage, wrinkling, peeling, and foreign matter inclusion can be avoided during the spoke shaping process. This results in a more streamlined wheel hub with higher structural strength, better integration, and improved overall mechanical properties.

[0019] Preferably, the inner circumferential wall of the first cavity support is provided with a forming annular inclined surface that slopes from top to bottom and from the outside to the inside. The forming annular inclined surface facilitates better shaping of the wheel spokes and also makes it easier to ensure that the rim diameter of the deep cylindrical blank is larger than the wheel rim diameter. This avoids issues such as rim breakage, wrinkling, peeling, and foreign matter inclusion during the wheel spoke shaping process, resulting in a smoother wheel hub with higher structural strength, better integration, and better overall mechanical properties.

[0020] Preferably, the outer peripheral wall of the first lower die is provided with a first annular notch in the circumferential direction; the annular notch and the first wheel hub cavity form a first wheel rim cavity; the first upper die and the first lower die are simultaneously driven to extrude and form a deep cylindrical cavity containing a wheel rim shape inside the combined state; the first ejector rod is vertically connected to the first lower die, and during ejection, the first ejector rod passes through the first lower die from bottom to top and pushes onto the deep cylindrical blank. The deep cylindrical blank is formed by cold extrusion through the cooperation of the first upper die and the first lower die, and the deep cylindrical blank is conveniently ejected by the first ejector rod, thereby facilitating the transfer of the deep cylindrical blank to the next process.

[0021] Preferably, the second mold includes a second upper mold, a second lower mold, a second ejector pin, and a second cavity support; the second cavity support is hollow and the hollow part of the second cavity support forms a second hub cavity; the desired wheel spoke shape is obtained by cold extrusion through the cooperation of the second upper mold and the second lower mold.

[0022] Preferably, the inner circumferential wall of the second cavity support is provided with an annular stepped surface running from top to bottom and from the outside to the inside. The annular stepped surface facilitates better compression of the wheel spokes at the step, thereby making the wheel spokes easier to shape, improving strength and aesthetics.

[0023] Preferably, the bottom surface of the second upper die is provided with a convex strip corresponding to the shape of the wheel spokes; the top surface of the second lower die is provided with a strip-shaped concave surface matching the convex strip; a second annular notch is provided circumferentially on the outer peripheral wall of the second lower die; a second rim cavity is formed between the second annular notch and the second hub cavity; a push rod protrusion is provided on the top of the second push rod; the second upper die, the second lower die, and the second push rod are combined to press the deep cylindrical blank into a secondary blank containing the shape of wheel spokes. The downward pressing of the second upper die facilitates the cold extrusion forming of the wheel spokes.

[0024] Preferably, the third mold includes a third upper mold I, a third upper mold II, a third lower mold, at least two sliders disposed on the side, and a third ejector rod. The secondary rough blank is placed on the third lower mold, and the sliders disposed on the side are used to fix the secondary rough blank. The third upper mold II is sleeved on the third upper mold I. The rim is initially shaped by pressing down with the third upper mold I, and then the top of the rim is cold-extruded and shaped by pressing down with the third upper mold II, finally obtaining the finished wheel hub in the shape of the rim. The third ejector rod is connected to the middle of the third lower mold for lifting. During ejection, the third ejector rod passes through the third lower mold from bottom to top and pushes onto the finished wheel hub to remove the finished wheel hub.

[0025] Preferably, the top surface of the third lower mold is provided with a support surface corresponding to the shape of the spokes; the lower part of each slider is provided with a slider step surface that matches the shape of the annular step surface; the upper part of the slider is provided with a rim step surface that runs from top to bottom and from the outside to the inside, the top of the rim step surface forms a rim end forming notch, and the rim step surface mates with the rim; the outer peripheral wall of the third upper mold I is provided with a rim mating surface that runs from top to bottom and from the outside to the inside; the bottom surface of the third upper mold I is provided with a spoke-shaped cavity surface that is the same as the top surface of the second lower mold; The third upper mold II is fitted outside the third upper mold I and is located above the third upper mold II. The bottom of the third upper mold II has a ring-shaped rim end forming notch. The third upper mold II presses down, pressing the rim end forming notch against the rim end forming notch. The rim end is extruded and shaped by the engagement of the rim end forming notch with the rim end forming notch. The third mold also includes a third ejector rod, which is vertically connected to the middle of the third lower mold. During ejection, the third ejector rod passes through the third lower mold from bottom to top and pushes onto the finished wheel hub. By inverting the rough blank onto the third mold and through the extrusion engagement between the third upper mold I and the third lower mold, the rim is better shaped and expanded outwards, thereby improving connection strength and performance.

[0026] In summary, the advantages of the method in this application are: higher wheel hub density, significantly improved structural strength, better wheel hub surface finish (typically exceeding 0.4), eliminating the need for further processing, higher structural strength, and superior quality; significant savings in raw materials during wheel hub production, eliminating the need for milling spokes from the wheel hub blank using processing equipment, thus saving equipment and labor costs; the wheel hub does not disrupt the flow lines of the raw materials, achieving better structural strength and mechanical properties, and avoiding defects such as cracks, porosity, folds, or non-metallic inclusions; smoother wheel hub flow lines, higher structural strength, better integration, and better overall mechanical properties; fewer production steps, with the three-step extrusion wheel hub requiring only minor finishing processes to complete the process, effectively improving production efficiency and saving manpower and resources. Attached Figure Description

[0027] Figure 1 This is a flowchart of the method for cold extrusion processing of wheel hubs according to the present invention.

[0028] Figure 2 This is a schematic diagram of step one in the cold extrusion processing method for wheel hubs according to the present invention.

[0029] Figure 3 This is a planar structural diagram of the deep cylindrical blank (rim larger than wheel rim) in this invention.

[0030] Figure 4 This is a three-dimensional structural diagram of the deep cylindrical blank (rim larger than wheel rim) in this invention.

[0031] Figure 5 This is a schematic diagram of step two in the cold extrusion processing method for wheel hubs according to the present invention.

[0032] Figure 6 This is a schematic diagram of step three in the cold extrusion processing method for wheel hubs according to the present invention.

[0033] Figure 7 This is an exploded view of step three in the cold extrusion processing method for wheel hubs of the present invention.

[0034] Figure 8 This is a schematic diagram of the structure of the finished wheel hub in this invention.

[0035] Figure 9 It is a structural cross-sectional view of an existing deep cylindrical blank (the rim is smaller than the wheel rim).

[0036] Figure 10 This is a schematic diagram illustrating the streamline formation principle during the existing extrusion wheel spoke forming process.

[0037] Wherein: 1. Deep cylindrical blank; 101. Flange; 102. Spoke; 103. Rim; 110. First upper die; 120. First lower die; 130. First ejector pin; 140. First cavity support; 150. Forming annular inclined surface; 170. First annular notch; 180. First rim cavity; 2. Secondary blank; 210. Second upper die; 2101. Convex strip; 220. Second lower die; 2201. Strip-shaped concave surface; 2202. Second annular notch; 2203. Second... 230. Rim cavity; 230. Second ejector pin; 2301. Ejector pin protrusion; 240. Second cavity support seat; 250. Annular step surface; 3. Finished wheel hub; 310. Third upper mold I; 3101. Rim mating surface; 320. Third lower mold; 3201. Support surface; 330. Slider; 3301. Slider step surface; 3302. Rim step surface; 340. Third ejector pin; 350. Third upper mold II; 3501. Rim end forming concave surface; 3502. Rim end forming notch. Detailed Implementation

[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0039] It should be noted that although functional modules are divided in the system diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the system or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0040] Existing wheel hubs such as Figure 9 and Figure 10 As shown, the rim 101 of the wheel hub is smaller than the spokes 102, which may result in defects such as foreign objects easily getting stuck in the intersection area, poor adhesion, folding, and cracks.

[0041] This invention provides a method for cold extrusion processing of wheel hubs, which can improve the product yield and is produced at room temperature, with significantly improved safety compared to high-temperature environments.

[0042] like Figures 1 to 8 As shown, the method for cold extrusion processing of wheel hubs includes the following steps:

[0043] S1. Deep cylindrical billet forming: Take a malleable metal material and place it into the first mold. Take a disc-shaped malleable metal material and place it into the first mold. The first mold uses a cold extrusion process to extrude the disc-shaped malleable metal material into a U-shaped deep cylindrical billet 1 with the opening facing downward. The upper part of the deep cylindrical billet 1 is the spoke 102, and the lower part of the deep cylindrical billet 1 is the rim 102. The diameter of the rim 101 of the deep cylindrical billet 1 is larger than the diameter of the rim 103 of the deep cylindrical billet 1. Finally, the deep cylindrical billet 1 is taken out from the first mold. The first mold includes a first upper mold 110, a first lower mold 120, a first ejector pin 130, and a first cavity support 140; the first cavity support 140 is hollow and the hollow part of the first cavity support 140 forms a first hub cavity; the first upper mold 110 and the first lower mold 120 cooperate to simultaneously cold extrude towards the middle to obtain a deep cylindrical blank 1 containing a protruding rim 101, so that the diameter of the rim 101 of the deep cylindrical blank 1 is larger than the diameter of the rim 103 of the deep cylindrical blank 1, and the deep cylindrical blank 1 is ejected from the first mold by the first ejector pin 130;

[0044] S2. Secondary rough blank forming: The deep cylindrical rough blank 1 is placed into the second mold. The second mold uses a cold extrusion process to extrude the deep cylindrical rough blank 1 to obtain the secondary rough blank 2 with the desired spoke shape. The spoke 102 of the secondary rough blank 2 is extruded to form spoke notches on both the upper and lower sides of the center. An extrusion step is formed on the outer wall of the rim 101 of the secondary rough blank 2. The extruded secondary rough blank 2 is then removed from the second mold. The second mold includes a second upper mold 210, a second lower mold 220, a second ejector pin 230, and a second cavity support 240. The second cavity support 240 is hollow, and the hollow portion of the second cavity support 240 forms a second hub cavity. The secondary rough blank 2 with the desired spoke 102 shape is obtained through cold extrusion using the cooperation of the second upper mold 210 and the second lower mold 220.

[0045] S3. Wheel hub forming: The secondary rough blank 2 is rotated 180° and placed into the third mold. The third mold first shapes the rim 103 of the secondary rough blank 2 through a cold extrusion process, making the rim 103 flared. Then, the top of the rim 103 is cold extruded and bent outward to form the finished wheel hub in the shape of the rim 103. The third mold includes: a third upper mold I 310, a third lower mold 320, and at least two sliders 330 set on the side. The secondary rough blank 2 is placed on the third lower mold 320 and fixed by the sliders 330 set on the side. The third upper mold II 350 is fitted on the third upper mold I 310. The rim 103 is first initially shaped by pressing down with the third upper mold I 310, and then the end of the rim 103 is cold extruded by pressing down with the third upper mold II 350 to form the finished wheel hub 3 in the shape of the rim 103.

[0046] like Figure 9 and Figure 10 As shown, in related technologies, the diameter of the rim 101 of the deep cylindrical blank 1 obtained by extrusion is equal to or smaller than the diameter of the rim 103. In this method, during the processing of the spoke 102 shape, the outer ring of the second die easily presses against the inner ring of the top of the hub when extruding the hub. This causes the spoke 102 to be pressed towards the rim 101, resulting in a thinner rim 101 and subsequent compression and folding of the metal material at the rim 101. In these related technologies, the streamlines of the extruded spoke 102 shape material converge, disrupting the overall streamline of the product. Defects such as foreign matter inclusions, weak adhesion, folding, and cracks are prone to occur in the convergence area, resulting in low structural strength and poor durability. Conversely, if the diameter of the rim 101 of the deep cylindrical blank 1 is larger than the diameter of the rim 103, even if the spoke 102 is pressed towards the rim 101, it will not affect the intersection of the spoke 102 and the rim 101, and will not affect the overall structural strength.

[0047] The specific steps for cold extrusion machining of wheel hubs are as follows:

[0048] like Figures 2 to 4As shown, the first step involves selecting a malleable metal material of appropriate quality based on the size and shape of the wheel hub. This malleable metal material is then vertically placed in the first mold, which consists of an upper mold 110 and a lower mold 120. The upper mold 110 and lower mold 120 simultaneously press towards the center, forming a deep cylindrical cavity containing the rim 101 in a combined state. Conventionally, during extrusion, only the upper mold 110 is pressed down, while the lower mold 120 remains fixed. This results in a higher tonnage requirement for the upper mold 110. However, by simultaneously pressing from both above and below, the tonnage requirement for the upper mold 110 is lower, while the lower mold 120 and upper mold 110 extrude the wheel hub, achieving a better shaping effect. The first lower die 120 and the first upper die 110 are used to extrude malleable metal material to obtain a deep cylindrical blank 1 containing the shape of a rim 101. The diameter of the rim 101 of the deep cylindrical blank 1 is larger than the diameter of the rim 103. Machining a blank with a larger rim 101 is beneficial for subsequent steps to process the shape of the spokes 102. The larger diameter of the rim 101 can reduce the possibility of flow line intersection, poor adhesion, folding and cracking at the edge, and can improve the mechanical strength of the product.

[0049] like Figure 2 As shown, in the first mold of the wheel hub mold, the inner circumferential wall of the first cavity support 140 is provided with a forming annular inclined surface 150 that slopes from top to bottom and from outside to inside. The forming annular inclined surface 150 facilitates better forming of the spokes 102, and also makes it easier to ensure that the diameter of the rim 101 of the deep cylindrical blank 1 is larger than the diameter of the wheel rim 103 of the deep cylindrical blank 1. This avoids breakage, wrinkling, peeling, and foreign matter inclusion at the rim 101 position during the process of forming the spokes 102 shape, resulting in a smoother wheel hub with higher structural strength, better integration, and better overall mechanical properties.

[0050] like Figure 2 As shown, the outer peripheral wall of the first lower die 120 is provided with a first annular notch 170 in the circumferential direction; the first annular notch 170 and the first hub cavity form a first rim cavity 180; the first upper die 110 and the first lower die 120, in their combined state, form a deep cylindrical cavity containing the shape of a rim 101; the first ejector rod 130 is vertically connected to the first lower die 120; during ejection, the first ejector rod 130 passes through the first lower die 120 from bottom to top and pushes onto the deep cylindrical blank 1. The deep cylindrical blank 1 is formed by cold extrusion through the cooperation of the first upper die 110 and the first lower die 120, and the deep cylindrical blank 1 is conveniently ejected by the first ejector rod 130, thereby facilitating the transfer of the deep cylindrical blank 1 to the next process.

[0051] In the first step, the malleable metal material is extruded through the first die to obtain a deep cylindrical blank 1 containing a protruding rim 101 shape. The deep cylindrical blank 1 with the protruding rim 101 shape can facilitate the formation of the spoke 102 shape, and can avoid the occurrence of rim 101 position breakage, wrinkling, peeling and foreign matter inclusion in the process of forming the spoke 102 shape. The wheel hub produced by the cold extrusion processing method of this application has a smoother streamline, higher structural strength, better integrity and better overall mechanical properties.

[0052] like Figure 5 As shown, in the second step, the deep cylindrical blank 1 is placed in the second lower die 220 of the second mold. The bottom of the second upper die 210 of the second mold is provided with a convex strip 2101 corresponding to the shape of the spoke 102. The shape of the mold can be flexibly changed according to the shape of the spoke 102. The second upper die 210 and the second lower die 220 are used to extrude the secondary blank 2 containing the shape of the spoke 102. The secondary blank 2 formed in one step has a smoother flow line, higher structural strength, and no defects such as material flow line convergence will occur.

[0053] In the second mold of the wheel hub mold, the inner circumferential wall of the second cavity support 240 is provided with an annular stepped surface 250 that runs from top to bottom and from the outside to the inside. The annular stepped surface 250 facilitates better compression of the wheel spokes 102 at the step, thereby making the wheel spokes 102 easier to shape, improving strength and aesthetics. The bottom surface of the second upper die 210 is provided with a convex strip 2101 corresponding to the shape of the spoke 102; the top surface of the second lower die 220 is provided with a strip-shaped concave surface 2201 matching the convex strip 2101; the outer peripheral wall of the second lower die 220 is provided with a second annular notch 2202 circumferentially; a second rim cavity 2203 is formed between the second annular notch 2202 and the second hub cavity; the top of the second ejector pin 230 of the second lower die 220 is provided with an ejector pin protrusion 2301; the second upper die 210, the second lower die 220, and the second ejector pin 230 are combined to press the deep cylindrical blank 1 into a secondary blank 2 containing the shape of the spoke 102. The pressing down of the second upper die 210 facilitates the cold extrusion forming of the spoke 102.

[0054] like Figures 6 to 7As shown, in the third step, since the shape of the wheel hub has been basically completed in the second roughing stage, only the shape of the rim 103 needs to be processed in the third process. The second roughing blank 2 is fixed on the third lower die 320, and the second roughing blank 2 is fixed using the slider 330 set on the side. The third upper die II 350 is fitted on the third upper die I 310. First, the rim 103 is initially shaped by pressing down with the third upper die I 310, and then the end of the rim 103 is cold extruded and formed by pressing down with the third upper die II 350, finally obtaining the finished wheel hub 3 with the shape of the rim 103. Further, after obtaining the finished wheel hub 3 with the shape of the rim 103, it is necessary to perform a small amount of finishing work such as deburring and drilling bolt holes, as well as surface coating.

[0055] In forged wheel hub processing, the forming method is usually spinning followed by turning. In cast wheel hub processing, the top of the rim is prone to breakage due to insufficient density and low strength. However, the two-stage extrusion method described in this application, where the lower part of the rim 103 is initially shaped using the third upper die I 310, and then the top of the rim 103 is extruded using the third upper die II 350, allows for different pressure values ​​in the two stages, facilitating better shaping of the top of the rim 103 while ensuring the integrity and precision requirements of the rim 103.

[0056] like Figures 6 to 8As shown, in the third mold of the wheel hub mold, the top surface of the third lower mold 320 is provided with a support surface 3201 corresponding to the shape of the spoke 102; the lower part of each slider 330 is provided with a slider step surface 3301 that matches the shape of the annular step surface 250; the upper part of the slider 330 is provided with a rim step surface 3302 that runs from top to bottom and from the outside to the inside, the top of the rim step surface 3302 forms a rim end forming concave surface 3501, and the rim step surface 3302 mates with the rim 103; the outer peripheral wall of the third upper mold I 310 is provided with a rim mating surface 3101 that runs from top to bottom and from the outside to the inside; the bottom surface of the third upper mold I 310 is provided with a spoke-shaped cavity surface that is the same as the top surface of the second lower mold 220. The third upper die II 350 is fitted outside the third upper die I 310 and is located above the third upper die II 350. The bottom of the third upper die II 350 has a ring-shaped rim end forming concave surface 3501. The third upper die II 350 presses down, causing the rim end forming concave surface 3501 to press onto the rim end forming recess 3502. The rim end forming concave surface 3501 and the rim end forming recess 3502 cooperate to extrude and shape the end of the rim 103. By inverting the secondary blank 2 onto the third die, and through the extrusion fit between the third upper die I 310 and the third lower die 320, the rim 103 is better shaped and expanded outwards, thereby improving connection strength and performance. The third mold also includes a third ejector rod 340, which is flexibly connected to the middle of the third lower mold 320. During ejection, the third ejector rod 340 passes through the third lower mold 320 from bottom to top and pushes onto the finished wheel hub 3. The flexibly connected third ejector rod 340 facilitates the ejection of the finished wheel hub 3.

[0057] The commonly used malleable metal materials are 6061 aluminum alloy or 6082 aluminum alloy. Aluminum alloy is a common material for wheel hubs, with advantages such as high structural strength. Aluminum alloy has a low density, resulting in lightweight wheel hubs with high structural strength, which is beneficial for lightweight vehicle production. Of course, other alloy materials can also be used, such as malleable alloy materials that meet the requirements for wheel hubs.

[0058] like Figure 6 and Figure 7As shown, there can be two sliders 330, each with a semi-circular cross-section. By combining the two sliders 330 and cooperating with the third lower die 320, the secondary blank 2 can be well fixed. The finished wheel hub 3 with the rim 103 shape can be obtained by the extrusion of the two sliders 330 and the third upper die I 310. There can also be three or more sliders 330. The secondary blank 2 is fixed on the third lower die 320 by the cooperation of the three sliders 330. Since both the sliders 330 and the third upper die I 310 have the rim 103 shape, the secondary blank 2 can be cold extruded by the third upper die I 310 to obtain the finished wheel hub 3 with the rim 103 shape. The setting of three sliders 330 can shorten the formation of the sliders 330 and improve the production efficiency.

[0059] The ratio of the diameter of the rim 101 to the diameter of the rim 103 of the deep cylindrical blank 1 is between 1.09 and 1.15. The ratio of the diameter of the rim 101 to the diameter of the rim 103 of the deep cylindrical blank 1 can be 1.09 or 1.15. By reasonably setting the size of the diameter of the rim 101 and the diameter of the rim 103, the possibility of unreasonable flow lines of the rim 101 in the second process can be effectively reduced, and the overall strength of the finished product can be improved, which has good practical value.

[0060] The cold extrusion method for producing wheel hubs provided in this embodiment only requires three cold extrusion operations on the malleable alloy material at room temperature to obtain the finished wheel hub 3. Compared with conventional casting and forging-spinning processes, the cold extrusion method for producing wheel hubs provided in this embodiment can greatly improve the efficiency of wheel hub production, ensure safe and environmentally friendly production at room temperature, significantly save raw materials, reduce processes, lower costs, and improve quality, achieving technological innovation in wheel hub production and possessing high economic value.

[0061] The present invention also provides an electronic device, comprising: a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method for cold extrusion processing of wheel hubs as described above. The processor and the memory can be connected via a bus or other means. The memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, the memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0062] In summary, the advantages of this application are: higher wheel hub density, significantly improved structural strength, better wheel hub surface finish (typically exceeding 0.4), eliminating the need for further processing, higher structural strength, and superior quality; significant savings in raw materials during wheel hub production, eliminating the need for milling spokes from the wheel hub blank using processing equipment, thus saving equipment and labor costs; the wheel hub does not disrupt the flow lines of the raw materials, achieving better structural strength and mechanical properties, and avoiding defects such as cracks, porosity, folds, or non-metallic inclusions; smoother wheel hub flow lines, higher structural strength, better integration, and better overall mechanical properties; fewer production steps, with the three-step extrusion wheel hub requiring only minor finishing processes, effectively improving production efficiency and saving manpower and resources.

[0063] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. These equivalent modifications or substitutions are all included within the scope defined by the claims of the present invention, such as using the method or equipment provided in this application for warm extrusion or hot forging.

[0064] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for cold extrusion processing of wheel hubs, characterized in that, Includes the following steps: S1. Deep cylindrical billet forming: A disc-shaped malleable metal material is placed in the first mold. The first mold uses a cold extrusion process to extrude the disc-shaped malleable metal material into a U-shaped deep cylindrical billet (1) with the opening facing downwards. The upper part of the deep cylindrical billet (1) is the spoke (102), and the lower part of the deep cylindrical billet (1) is the rim (103). The diameter of the rim (101) of the deep cylindrical billet (1) is larger than the diameter of the rim (103) of the deep cylindrical billet (1). The ratio of the diameter of the rim (101) of the deep cylindrical billet (1) to the diameter of the rim (103) of the deep cylindrical billet (1) is between 1.09 and 1.

15. Finally, the deep cylindrical billet (1) is taken out from the first mold. The first mold includes a first upper mold (110), a first lower mold (120), a first ejector pin (130), and a first cavity support seat (140); the first cavity support seat (140) is hollow and the hollow part of the first cavity support seat (140) forms a first hub cavity; the first upper mold (110) and the first lower mold (120) cooperate to simultaneously cold extrude towards the middle to obtain a deep cylindrical blank (1) containing a protruding rim shape, so that the diameter of the rim (101) of the deep cylindrical blank (1) is larger than the diameter of the spoke (102) of the deep cylindrical blank (1), and the deep cylindrical blank (1) is ejected from the first mold by the first ejector pin (130); S2, Secondary blank forming: The deep cylindrical blank (1) is placed in the second mold, and the second mold extrudes the deep cylindrical blank (1) to obtain the secondary blank (2) with the desired spoke (102) shape by cold extrusion process; the spoke (102) center of the secondary blank (2) is extruded to form spoke notches on both the upper and lower sides; and the outer wall of the rim (101) of the secondary blank (2) is extruded to form extrusion steps; the extruded secondary blank (2) is taken out from the second mold; S3, hub forming: The secondary blank (2) is rotated 180° and placed into the third mold. The third mold first shapes the rim (103) of the secondary blank (2) through cold extrusion process, so that the rim (103) is flared. Then the top of the rim (103) is cold extruded and bent outward to form the finished hub (3) with the shape of the rim (103). The third mold includes a third upper mold I (310), a third upper mold II (350), a third lower mold (320), at least two sliders (330) set on the side and a third ejector rod (340). The secondary blank (2) is placed on the third lower mold (320) and the secondary blank (2) is fixed by the sliders (330) set on the side. The third upper mold II (350) is sleeved on the third upper mold I (310). First, the rim (103) is initially shaped by pressing down the third upper mold I (310), and then the top of the rim (103) is cold extruded and shaped by pressing down the third upper mold II (350), and finally the finished wheel hub (3) in the shape of the rim (103) is obtained.

2. The method for cold extrusion processing of wheel hubs according to claim 1, characterized in that, The inner circumferential wall of the first cavity support (140) is provided with a shaped annular inclined surface (150) that slopes from top to bottom and from outside to inside.

3. The method for cold extrusion processing of wheel hubs according to claim 1, characterized in that, The outer peripheral wall of the first lower die (120) is provided with a first annular notch (170) in the circumferential direction; the annular notch (170) and the first wheel hub cavity form a first wheel rim cavity (180); the first upper die (110) and the first lower die (120) are simultaneously driven to extrude and form a deep cylindrical cavity containing a wheel rim shape inside the combined state; the first ejector rod (130) is connected to the first lower die (120) in a lifting manner; when ejecting, the first ejector rod (130) passes through the first lower die (120) from bottom to top and pushes onto the deep cylindrical blank (1).

4. The method for cold extrusion processing of wheel hubs according to claim 1, characterized in that, The second mold includes a second upper mold (210), a second lower mold (220), a second ejector pin (230), and a second cavity support seat (240); the second cavity support seat (240) is hollow and the hollow part of the second cavity support seat (240) forms a second hub cavity; the second upper mold (210) and the second lower mold (220) cooperate with each other to cold extrude a secondary rough blank (2) with the desired spoke (102) shape.

5. The method for cold extrusion processing of wheel hubs according to claim 4, characterized in that, The inner circumferential wall of the second cavity support (240) is provided with an annular stepped surface (250) that runs from top to bottom and from the outside to the inside.

6. The method for cold extrusion processing of wheel hubs according to claim 4, characterized in that, The bottom surface of the second upper die (210) is provided with a convex strip (2101) corresponding to the shape of the spoke (102); the top surface of the second lower die (220) is provided with a strip-shaped concave surface (2201) matching the convex strip (2101); the outer peripheral wall of the second lower die (220) is provided with a second annular notch (2202) in the circumferential direction; the second annular notch (2202) and the second hub cavity form a second rim cavity (2203); the top of the second push rod (230) is provided with a push rod protrusion (2301); the second upper die (210), the second lower die (220) and the second push rod (230) are combined to press the deep cylindrical blank (1) into a secondary blank (2) containing the shape of the spoke (102).

7. The method for cold extrusion processing of wheel hubs according to claim 1, characterized in that, The third push rod (340) is connected to the middle of the third lower mold (320) in a lifting manner; when ejecting, the third push rod (340) passes through the third lower mold (320) from bottom to top and pushes onto the finished wheel hub (3) to remove the finished wheel hub (3).

8. The method for cold extrusion processing of wheel hubs according to claim 7, characterized in that, The top surface of the third lower mold (320) is provided with a support surface (3201) corresponding to the shape of the spokes (102); the lower part of each slider (330) is provided with a slider step surface (3301) matching the shape of the annular step surface (250); the upper part of the slider (330) is provided with a rim step surface (3302) from top to bottom and from the outside to the inside, the top of the rim step surface (3302) forms a rim end forming notch (3502), and the rim step surface (3302) mates with the rim (103); the outer peripheral wall of the third upper mold I (310) is provided with a rim mating surface (3101) from top to bottom and from the outside to the inside; the bottom surface of the third upper mold I (310) is provided with the same as the top surface of the second lower mold (220). The wheel spoke-shaped cavity surface; the third upper mold II (350) is sleeved outside the third upper mold I (310) and located on the upper part of the third upper mold II (350); the bottom of the third upper mold II (350) is provided with a ring-shaped rim end forming concave surface (3501); the third upper mold II (350) presses down to press the rim end forming concave surface (3501) onto the rim end forming notch (3502); and the rim end forming notch (3502) and the rim end forming concave surface (3501) cooperate to extrude and shape the end of the rim (103); the third push rod (340) is connected to the middle of the third lower mold (320) for lifting and lowering; when ejecting, the third push rod (340) passes through the third lower mold (320) from bottom to top and pushes onto the finished wheel hub (3).

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