Method for avoiding forging fold of knuckle disc high rib inner arc

Abstract

The present application relates to the technical field of knuckle forging, and particularly relates to a method for avoiding knuckle disc high rib inner circular arc folding during forging, which forms a forged piece through heating, blank making, extrusion, pre-forging and final forging of raw materials, the disc high rib is extruded upward and shaped during final forging, the position is a plane during pre-forging, other parts of the knuckle are filled with the mold first and then flow outward during final forging, at the disc edge, the metal flows upward to form the high rib, after the final forging cavity is filled, the metal continues to flow outward to the flash groove, the shape of the pre-forging blank is adjusted, the metal flow during final forging is optimized, the metal can flow according to the preset order and direction, and thus the disc high rib can be smoothly extruded upward and shaped during the final forging stage, and the problem of metal folding at the inner circular arc caused by the traditional processing method is avoided.

Description

Technical Field

[0001] This invention relates to the field of steering knuckle forging technology, and in particular to a method for avoiding forging folds in the inner arc of the high-ribbed steering knuckle disc. Background Technology

[0002] In axle systems, the steering knuckle is a crucial component, directly affecting vehicle handling, safety, and driving stability. Depending on the vehicle model, automotive steering knuckles have various structures. For example, the disc steering knuckle used in Shaanxi Automobile Delong axles (reference model HD90009410559) is fork-shaped and mainly consists of three parts: a rod, a flange, and lugs. The rod is a frustum-shaped or stepped shaft, and the lugs include long and short lugs with coaxial kingpin holes. The flange also has claws at both ends.

[0003] The applicant disclosed a forging method for the steering knuckle in Chinese invention patent ZL2021109996840 (patent title: Method for Improving the Forging Quality of Steering Knuckle Disc), which involves heating the raw material, forming a billet, and then extruding, pre-forging, and finally forging the billet to form a forging. The appendix to this patent... Figure 1 The diagram shows the structure of the extruded steering knuckle blank, with appendix. Figure 2 Appendix Figure 3 A schematic diagram of the pre-forged steering knuckle blank is shown. (See attached diagram.) Figure 3 It can be seen that after pre-forging, reinforcing ribs are formed on both sides in the narrower direction of the disc. The structure and processing method of this steering knuckle are disclosed in another patent of the applicant, ZL2020114109359 (Patent title: Method for improving the elongation and contraction rate of the steering knuckle rod).

[0004] In existing technologies and the aforementioned patents, the steering knuckle has reinforcing ribs formed on the disc portion after processing, thereby increasing the strength of the disc portion and helping to reduce its thickness. When the width of the disc reinforcing ribs is large, their height can be low, making forging easier. For example, CN202138412U discloses a steering knuckle for a disc brake, which is another type of steering knuckle, and the reinforcing ribs of this steering knuckle are easy to form.

[0005] Regarding the aforementioned disc steering knuckle (HD90009410559), due to the small width and high height of the reinforcing ribs, which are classified as fine high ribs, the existing technology uses the same forming method as the ear part, i.e., the fine high ribs are first formed during pre-forging, and then the desired shape is obtained through final forging and upsetting. The applicant discovered during production that, with this high rib structure forming method, folds easily form at the inner arc of the high rib during final forging, thus affecting product quality. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for avoiding forging folds in the inner arc of the steering knuckle disc. By adjusting the shape of the pre-forged blank, the flow of metal during the final forging process is optimized, thus preventing folds from forming at the inner arc.

[0007] The technical solution adopted by this invention to solve its technical problem is: a method for avoiding forging folding of the inner arc of the high rib of the steering knuckle disc, wherein the raw material is heated, billeted, extruded, pre-forged, and finally forged to form a forging. The high rib of the disc is extruded upward and formed during the final forging. During the pre-forging, this position is a plane. During the final forging, other parts of the steering knuckle are filled to the full first. Then, as the upper die of the final forging mold continues to descend, the plane where the axis of the rod and the kingpin hole are located is M. The metal of the disc flows outward in a direction perpendicular to M. At the edge of the disc, the metal flows upward to form the high rib, and at the same time flows outward to increase the width of the disc. The side of the disc and the outer side of the high rib are the same continuous surface, forming a continuous metal flow line from the disc to the high rib at this edge. After the final forging cavity is filled, it continues to flow outward to the flash groove. The height of the high rib is 15-20mm, and the thickness of the high rib is 8-10mm. The width of the disc from the axis of the rod to the edge increases by 0.96%-1%, and the thickness of the disc decreases by 9.2%-9.6%.

[0008] Preferably, the pre-forged part obtained by pre-forging has a draft angle of 7° on the side of the disc at the edge where the high rib is to be formed, and the final forged part obtained by final forging has a draft angle of 6.5° on the outer side of the high rib.

[0009] Preferably, the side of the disc portion of the pre-forged part transitions to the side near the ear with an arc, the radius of which is 5mm, and the side of the high rib of the final forging transitions to the top surface with an arc, the radius of which is 3mm.

[0010] Preferably, the thickness of the pre-forged part from the side of the disc near the ear to the forging parting surface is 21 mm, and the thickness of the final forged part from the side of the disc near the ear to the forging parting surface is 19 mm.

[0011] Preferably, the high rib transitions from the long ear to the short ear along the edge contour of the disc portion.

[0012] Preferably, during final forging, the long and short lugs of the steering knuckle are upset, reducing their height.

[0013] The beneficial effects of this invention are: by adjusting the shape of the pre-forged blank, the flow of metal during the final forging process is optimized, so that the metal can flow in a preset order and direction, thereby the high ribs of the disc can be smoothly extruded and formed in the final forging stage, avoiding the problem of metal folding at the inner arc caused by traditional processing methods. Attached Figure Description

[0014] Figure 1This is a schematic diagram of the structure of the pre-forged steering knuckle blank processed by the present invention.

[0015] Figure 2 yes Figure 1 Sectional view at point AA.

[0016] Figure 3 This is a schematic diagram of the final forged blank of the steering knuckle processed by the present invention.

[0017] Figure 4 yes Figure 3 Sectional view at point BB.

[0018] Figure 5 This is a schematic diagram of the structure of the pre-forged steering knuckle blank processed by the present invention.

[0019] Figure 6 This is a schematic diagram of the final forging die of the present invention.

[0020] Figure 7 This is a schematic diagram of the deformation of the pre-forged blank in the final forging die cavity of the present invention.

[0021] Figure 8 This is a schematic diagram of the deformation of the pre-forged blank in the final forging die cavity of the present invention.

[0022] Figure 9 This is a schematic diagram of the folding formed by metal flow at the inner arc of the high rib of the steering knuckle disc in the existing technology.

[0023] Figure 10 This is a schematic diagram of metal flow at the inner arc of the high rib of the steering knuckle disc in this invention.

[0024] Explanation of reference numerals in the attached figures: 1 - Disc 2 - Long Ear 3 – Short ear 4 – Bar section 5 - High gluten content. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0026] like Figures 1-8 As shown, this embodiment describes the machining of the disc steering knuckle (reference model HD90009410559) of Shaanxi Automobile Delong axle, including the following steps:

[0027] 1. Heat the round steel to a suitable temperature and then perform billet preparation and extrusion to form an extruded blank.

[0028] 2. The extruded blank is pre-forged to obtain a pre-forged blank, the structure of which is as follows: Figure 1 , 2 As shown in Figure 5.

[0029] 3. The pre-forged blank is then forged to obtain the final forged blank, the structure of which is as follows: Figure 3 , 4 As shown.

[0030] 4. The final forged blank is then machined to obtain the final steering knuckle.

[0031] Specifically, during the pre-forging stage, the position of the high ribs in the disc is designed to be planar (see...). Figure 2 (The upper sides of the left and right ends of the middle plate). This method optimizes the local structure of the pre-forging blank by precisely adjusting the pre-forging cavity structure, so that the metal can flow in a preset order and direction during the final forging process. This results in the high ribs of the plate being able to be smoothly extruded upwards and formed in the final forging stage (see...). Figure 4 , Figure 10 ).

[0032] Specifically, the adjustment of the pre-forging cavity structure includes: compared to the pre-forging blank, the width of the disc portion of the final forging blank from the rod axis to the edge increases by 0.96%-1%, while the disc thickness decreases by 9.2%-9.6%. During final forging, if... Figure 7 , 8 As shown, other parts of the steering knuckle are filled first, and then as the upper die of the final forging mold continues to descend, the plane where the axis of the rod and the kingpin hole are located is M. The metal of the disc flows outward in a direction perpendicular to M. At the edge of the disc, the metal flows upward to form a high rib, and at the same time flows outward to increase the width of the disc. The side of the disc and the outer side of the high rib are the same continuous surface, forming a continuous metal flow line from the disc to the high rib at this edge. After the final forging cavity is filled, it continues to flow outward to the flash groove. The height of the high rib is 15-20mm, and the thickness of the high rib is 8-10mm.

[0033] Figure 5 This is a schematic diagram of the structure of a pre-forged blank. Figure 6 This is a schematic diagram of the final forging die. Figure 7 and Figure 8 The pre-forged blanks were compared between the lower mold cavity and the upper mold cavity of the final forging process. In the figure, the parting surface of the pre-forged blanks is aligned with the parting surface of the mold. Figure 7 In the process, the part where the outline of the pre-forged blank extends into the outline of the lower die, and the part where the outline of the lower die extends into the outline of the pre-forged blank, are the parts that deform at the end. In the vertical direction, the greater the length of the extension, the earlier the deformation and the greater the degree of deformation. Figure 8 Similarly. According to Figure 7 , Figure 8 It can be seen that this method determines the direction of metal flow and the approximate distribution of metal during the final forging process.

[0034] If, according to existing technology, high ribs are formed during pre-forging, and then locally upset at the end (like the ear section), the high-rib cavity in the final forging will quickly fill with metal, which then flows towards the disc. Meanwhile, the metal in the disc also flows towards the high ribs, thus creating folds at the inner arc. Figure 9 As shown. For non-high-rib products, if the rib width is large, more metal can be accommodated due to the larger width, and the above-mentioned problem does not exist. Only the products processed in this application and products with similar structures have a large height and small thickness of high ribs, and the above-mentioned problem exists.

[0035] Furthermore, in the pre-forging obtained by pre-forging, the draft angle of the disc side at the edge of the high rib is 7°. In the final forging obtained by final forging, the draft angle of the outer side of the high rib is reduced to 6.5°. This reduction in draft angle makes the disc wider as it flows outward, while the resistance on the upper side of the edge is smaller. This helps to alleviate the pressure of metal being squeezed into the high rib cavity and prevents the metal from flowing upward from the edge of the disc into the high rib cavity.

[0036] Furthermore, the side of the disc portion of the pre-forged part transitions to the side near the ear with an arc, the radius of which is 5mm, and the side of the high rib of the final forging transitions to the top surface with an arc, the radius of which is 3mm.

[0037] Furthermore, the thickness of the pre-forged part from the side of the disc near the ear to the forging parting surface is 21 mm, and the thickness of the final forged part from the side of the disc near the ear to the forging parting surface is 19 mm.

[0038] Furthermore, the high rib transitions from the long ear to the short ear along the edge contour of the disc portion.

[0039] Furthermore, during final forging, the long and short lugs of the steering knuckle are locally upset, reducing their height.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for avoiding forging folds in the high-ribbed inner arc of the steering knuckle disc, wherein the raw material is heated, billeted, extruded, pre-forged, and finally forged to form a forging, characterized in that: The high ribs of the disc are extruded and formed upwards during final forging. During pre-forging, the high ribs of the disc are in a planar position. During final forging, other parts of the steering knuckle are filled first, and then the upper die of the final forging mold continues to descend. The plane where the rod axis and the kingpin hole are located is M. The metal of the disc flows outward in a direction perpendicular to plane M where the rod axis and the kingpin hole are located. At the edge of the disc, the metal flows upward to form high ribs, and at the same time flows outward to increase the width of the disc. The side of the disc and the outer side of the high ribs are the same continuous surface, forming a continuous metal flow line from the disc to the high ribs at this edge. After the final forging cavity is filled, the metal continues to flow outward to the flash groove. The height of the high ribs is 15-20mm, and the thickness of the high ribs is 8-10mm. The width of the disc from the rod axis to the edge increases by 0.96%-1%, and the thickness of the disc decreases by 9.2%-9.6%. The pre-forged part obtained by pre-forging has a draft angle of 7° on the side of the disc at the edge where the high rib is to be formed, and the final forged part obtained by final forging has a draft angle of 6.5° on the outer side of the high rib. The side of the disc of the pre-forged part transitions to the side near the ear with an arc with a radius of 5mm, and the side of the high rib of the final forging transitions to the top surface with an arc with a radius of 3mm. The thickness of the pre-forged part from the side of the disc near the ear to the forging parting surface is 21 mm, and the thickness of the final forged part from the side of the disc near the ear to the forging parting surface is 19 mm.

2. The method for avoiding forging folds in the high-ribbed inner arc of the steering knuckle disc according to claim 1, characterized in that: The high rib transitions from the long ear to the short ear along the edge contour of the disc.

3. The method for avoiding forging folds in the high-ribbed inner arc of the steering knuckle disc according to claim 1, characterized in that: During final forging, the long and short lugs of the steering knuckle are upset, reducing its height.

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