A manufacturing method of a front axle of a large-tonnage large-wheel-base mining truck

Abstract

The present application relates to axle forging technical field, especially to a kind of large tonnage large wheelbase mining truck front axle manufacturing method, it is through fractionalization, sectional forming method to share equipment pressure and reduce roll forging bag angle requirement, realize roll die forging integration production on existing ordinary front axle production line, greatly reduce the product weight, reduce labor intensity, improve the material utilization rate of product, production efficiency and product quality, ensure that the size precision of mining truck front axle is controllable in production, and the safety of use.The realization of the forging process production of the mining truck front axle also provides technical reference for the production of other large die forgings, has important technical and economic value, further improves the competitiveness of company.

Description

Technical Field

[0001] This invention relates to the field of axle forging technology, and in particular to a method for manufacturing a front axle for a large-tonnage, wide-wheelbase mining truck. Background Technology

[0002] Automobile front axles are generally manufactured using forging processes to ensure their strength. For example, our company's patent 011283297, filed in 2001, describes a combined roll forging and die forging process for automobile front axles. This process, through calculated mold design and optimized production flow, achieves a one-piece formed front axle, improving quality and production efficiency, and enhancing the company's competitiveness. This front axle roll forging process is primarily used for the production of front axles in ordinary automobiles, specifically those not exceeding 1.9m in length and with a maximum rated load not exceeding 9 tons.

[0003] Mining trucks are off-highway vehicles, primarily used in mining and engineering projects. They carry heavier loads and are more durable than regular vehicles. Structurally, mining trucks and ordinary dump trucks don't seem significantly different, except that mining trucks are larger. However, because mining trucks have longer front axles, typically 2.2 to 2.6 meters long, with larger cross-sections and a greater load capacity (up to 30 tons), manufacturing them using forging processes is more difficult and requires ultra-large tonnage forging equipment. While using ultra-large tonnage forging equipment offers high efficiency and good forging quality, it also involves significant equipment investment, a long manufacturing cycle, and high operating costs. Furthermore, if not forging large parts like mining truck front axles, these forgings may remain idle due to economic factors, resulting in waste.

[0004] Therefore, front axles used in mining trucks are generally produced using a steel plate welding process, which results in long production cycles, high costs, large and heavy product sizes (over 600 kg), and difficulties in ensuring and controlling product dimensions and welding quality. Desoldering and breakage failures frequently occur during use. Therefore, considering both safety and economy, it is of great significance to realize the forging process for mining truck front axles under existing tonnage equipment conditions (the configuration of a forging production line for ordinary automobile front axles). Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for manufacturing front axles of large-tonnage, wide-wheelbase mining trucks. By optimizing existing front axle processes and combining them with the company's existing production technology conditions, and through meticulous analysis and calculation, the invention adopts a modular approach, dividing the axle into sections for forming and rationally arranging the forging process. This enables the integrated forging production of ultra-long, ultra-wide, and ultra-heavy front axles, resulting in smaller, lighter, and stronger forged mining truck front axles.

[0006] The technical solution adopted by this invention to solve its technical problem is: a manufacturing method for the front axle of a large-tonnage, large-wheelbase mining truck, the process of which is as follows: blanking → heating → step-by-step roll forging → bending → segmented final forging → edge trimming → hot straightening → heat treatment → shot blasting → flaw detection → inspection and cold straightening; wherein...

[0007] 1) Step-by-step roll forging: Using a φ1000 roll forging machine, clamp one end of the round steel (this end is the clamping end, and the clamping...)

[0008] The holding part is the jaws, and the other end is the non-clamping end. The first step is integral roll forging. After the round steel is bitten by the roll forging die near the jaws, it is rolled while being pulled back to achieve preliminary metal distribution. At the same time, it widens the two steel plate positions, so that the difficult-to-form steel plate positions can be formed by upsetting in the subsequent process.

[0009] The second step is segmented roll forging. First, the roll forging die engages the non-clamping end, and then the billet is pulled out. The non-clamping end of the roll forging billet accounts for 1 / 4 to 1 / 3 of the total length. Then, the roll forging die engages the clamping end close to the jaws, and then the billet is pulled out. The remaining section of the roll forging billet accounts for 2 / 3 to 3 / 4 of the total length.

[0010] 2) Press bending: Using a hydraulic press or electric screw press, the blank is pressed and bent along the edges on a bending die that can contain the entire blank.

[0011] 3) Segmented final forging: Adopting the idea of ​​breaking down the whole into parts, first form the two steel plate positions of the front axle of the mining truck and the middle section between the two steel plate positions, and perform simple deformation on the parts other than the two ends of the two steel plate positions; then symmetrically form the part other than the two ends of the two steel plate positions, including the front axle fist, and perform finishing on the two steel plate positions and the middle section between the two steel plate positions; the final shape and size of the front axle of the mining truck are obtained by forming in two stages.

[0012] 4) Trimming: Trim the flash on the full-size blanking die. The cutting edge of the blanking die adopts a beveled blade with a wavy shape.

[0013] 5) Hot straightening: On a high-speed forging hydraulic press, a flat straightening method is used to straighten and locally shape the blank after the edges are cut.

[0014] Furthermore, the forged mining truck front axle of this invention weighs 250KG, is made of 42CrMo, is 2502mm long, has a middle I-beam width of 180mm and a height of 212mm, and has a 120mm drop between the upper surface of the I-beam and the center of the two end fists. The front axle is completely open, and the lower flange in the middle of the I-beam has a concave clearance groove. The web of the I-beam is 20mm thick, and the web thickness at the middle and end positions where the leaf spring seats are installed is 25-35mm thicker than other areas.

[0015] Furthermore, during step-by-step roll forging, an auxiliary support is provided between the roll forging mill and the clamping position to support the billet and prevent it from bending downwards. The billet has low strength at high temperatures and is prone to sagging and bending due to its own weight; the top of the auxiliary support can be a roller.

[0016] Furthermore, the front shaft straight billet finally formed by roll forging has a cross-sectional shape in each section that is close to the corresponding cross-section of the final forging cavity, and the cross-sectional area is equal to or greater than the corresponding cross-section of the final forging cavity by 0 to 500 mm. 2 .

[0017] Furthermore, the second step of roll forging uses two sets of roll forging dies. Each set of roll forging dies consists of two symmetrical upper and lower roll forging dies. The central angle of the first set of roll forging dies is 65° to 70°. The first set of roll forging dies rolls from the bend at one end of the front shaft to the fist at that end, including the fist. The central angle of the second set of roll forging dies is 225° to 235°. The second set of roll forging dies rolls from the fist at the other end of the front shaft to the starting rolling position of the first set of roll forging dies, excluding the fist. It can extend 0 to 50 mm beyond the starting rolling position of the first set of rolling dies.

[0018] Furthermore, the blank is bent with flash, and a vertical receiving groove is set on the bending die. The receiving groove structure is a straight groove or an open groove with a draft angle. The width of the receiving groove is 10-30mm, and the width is uniform or differentiated in the length direction.

[0019] Furthermore, the segmented final forging die includes a final forging die one for mainly forming the front axle steel plate position and the middle section between the two steel plate positions, and a final forging die two for mainly forming the parts outside the two ends of the two steel plate positions. Both dies are full-size dies and are symmetrical from left to right.

[0020] Furthermore, the dies for final forging one and final forging two are designed as follows:

[0021] 1) The cavity used for forming forgings is designed with negative deviation, that is, the sum of the cavity depths of the upper and lower dies is 3 to 4 mm less than the thickness of the finished forging;

[0022] 2) The overlap area between the two molds is 60-120mm, with a smooth transition;

[0023] 3) The flash bridge design uses a larger flared groove with open ends. The flared groove is 50% to 100% deeper than the usual (conventional front axle flared groove) and 50% narrower than the usual design, except for difficult-to-fill areas. The flash bridge thickness is 5 to 10 mm.

[0024] 4) For the final forging step 1, only the forming area of ​​the final forging step 1 is considered. For the final forging step 2, both the final forging step 1 and the final forging step 2 need to be considered.

[0025] Furthermore, after the final forging is completed, the flash of the mining truck front axle forging is arranged from the main body of the forging outward as follows: final forging flash 2, final forging flash 1, and roll forging flash. Among them, the roll forging flash is distributed on the inner and outer sides of the three bends of the forging, the flash of final forging flash 1 and final forging flash 2 surround the entire main body of the forging, and the flash thickness of final forging flash 2 within 10mm of the main body of the forging is 5-10mm.

[0026] This invention achieves integrated forging production of mining truck front axles that are longer, wider, and have a higher load capacity than existing front axles by breaking them down into smaller parts and forming them in segments, using existing front axle production lines. It has the following technical advantages:

[0027] 1) After adopting this technology, the weight of the front axle of the mining truck has been reduced from 642kg to 230kg, while the load remains the same and the weight is reduced by 64%.

[0028] 2) After the manufacturing process is changed to die forging, continuous forging production can be achieved on the existing 16,000T production line, saving costs.

[0029] Shooting time is 6 minutes per piece, with a daily production capacity of 150 pieces. Semi-automatic operation is possible, resulting in low labor intensity and high efficiency. 3) Product quality has been improved by changing from easily deformable welding to forging. Firstly, the material has been changed from Q235 steel plate to 42CrMo round steel, significantly increasing material strength. This results in higher overall forging quality and better dimensional control.

[0030] +3 / -1, good consistency, and the front axle undergoes overall heat treatment, allowing for excellent control of mechanical properties.

[0031] 880-1030 MPa.

[0032] 4) Less material is required, and the material utilization rate can reach 87%.

[0033] 5) This technology can be used not only to produce large mining truck front axles, but also to produce other large forgings, achieving low input, high output, low energy consumption, material saving, and environmental protection. Attached Figure Description

[0034] Figure 1 This is a finished product image of the front axle of a mining truck produced by the forging process of this invention;

[0035] Figure 2 This is a schematic diagram of a round steel section;

[0036] Figure 3 This is a schematic diagram of the rolling process during the first step of integral roll forging and a diagram of the front shaft straight billet formed after roll forging;

[0037] Figure 4 This is a schematic diagram of the rolling method of the non-clamping end during the second step of segmented roll forging, and a diagram of the front shaft straight billet formed after roll forging;

[0038] Figure 5 This is a schematic diagram of the rolling method for the remaining section during the second step of segmented roll forging, and a diagram of the front shaft straight billet formed after roll forging;

[0039] Figure 6 This is a drawing of a bent blank after the straight front axle blank has been pressed and bent.

[0040] Figure 7 This is a drawing of the formed forging after the final forging of the bent billet;

[0041] Figure 8 This is a drawing of the finished forging after the second final forging stage;

[0042] Figure 9 This is a diagram of the forging die for the non-clamping end during the second step of segmented roll forging;

[0043] Figure 10 This is a diagram of the forging die for the remaining section during the second step of segmented roll forging;

[0044] Figure 11 This is the front view of the bending die;

[0045] Figure 12 This is the main view of the upper die of the final forging dies 1 and 2;

[0046] Figure 13 This is the main view of the lower die of the final forging dies 1 and 2;

[0047] Figure 14 This is a schematic diagram of the cutting edge structure of the trimming die;

[0048] Figure 15 yes Figure 14 AA view. Detailed Implementation

[0049] 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.

[0050] Based on simulation analysis and calculation, the front axle of the mining truck in this embodiment is produced using 42CrMo round steel through a roll forging process, and the final product is as follows: Figure 1 As shown, the forging weighs 250 kg, the finished product weighs 230 kg, the total length is 2502 mm, the width is 180 mm, the height is 212 mm, and the horizontal projected area (area of ​​the front axis of symmetry) is 5605 cm². 2 The overall forging force required is approximately 22,420 tons of force, meaning that equipment or a production line with a capacity of 24,000 tons is needed to complete the forging of this product. Existing front axle production line forging equipment has pressures of 12,500T and 16,000T, making it difficult to form the forging as a whole in one go. Furthermore, considering the excessive length of the forging and the limited wrap angle of the roll forging die, this embodiment adopts a segmented forging method for the mining truck front axle. The specific forging process is as follows:

[0051] Cutting: Use a circular saw to obtain 42CrMo round steel segments, such as... Figure 2 As shown.

[0052] Heating: Place the round steel segment into a 2000KW medium-frequency heating furnace and heat it to 1170-1230℃.

[0053] Integral roll forging: Take out the round steel heated to about 1200℃, clamp one end, and insert the round bar into a roll forging die with a wrap angle of 232°, so that the roll forging die is aligned as follows. Figure 3 The shown biting point engages the round steel, and starting from this point, a backward pulling method is used to roll the round steel. All sections of the round steel, except for the jaws, are integrally roll-forged to achieve rough metal distribution. This mainly involves the initial parting along the length direction to create the steel plate position and the fist-shaped section of the front axle. The widening of the steel plate position, in particular, allows the difficult-to-form steel plate position to be formed in subsequent processes using upsetting, resulting in a shape similar to... Figure 3 The front axle straight blank is shown.

[0054] Non-clamping end of roll forging: Insert the front axle straight blank into... Figure 9 The forging die shown is positioned such that the die engagement distance is 1 / 4 to 1 / 3 of the distance from the non-clamping end of the billet, as... Figure 4 As shown, during the billet back drawing process, the billet is rolled to roughly form the non-clamping end of the billet into a front-axle large-bend straight billet with a cross-section of an inverted top hat shape to an I-beam shape and a fist-shaped billet with a rectangular cross-section, thus obtaining the following... Figure 4 The front axle straight blank is shown.

[0055] Remaining section of roll forging: Extend the front axle straight blank into... Figure 10 The molds shown are positioned such that the forging die clamps at both ends, as indicated. Figure 5 As shown, during the billet redrawing process, the rolled billet moves from the clamping end to the previous engagement position, resulting in another large curved straight billet with an I-shaped cross-section and a front axle steel plate position with an inverted top hat-shaped cross-section, as well as the section between the two steel plate positions, thus obtaining the following... Figure 5 The front axle straight blank is shown.

[0056] The entire roll forging process is divided into two steps, with the latter step further divided into two sections. This reduces the tonnage requirements of the rolling mill, avoids insufficient die wrap angle making it difficult to form excessively long forgings, and prevents defects caused by excessive deformation in a single step. During the latter roll forging step, to prevent the forging from bending under its own weight at high temperatures, auxiliary supports are installed between the roll forging machine and the clamping position to support the billet and prevent it from bending. Furthermore, the final front shaft straight billet formed by roll forging has cross-sectional shapes that closely approximate the corresponding cross-section of the final forging cavity, with a cross-sectional area equal to or greater than the corresponding cross-section of the final forging cavity by 0–500 mm². 2This facilitates easy forming and good filling of the blank during subsequent die forging. During roll forging, three roll forgings are completed in one clamping operation. The three roll forgings are drawn in the same direction, which ensures that the metal flows in a consistent direction along the length of the blank, thereby preventing the blank from folding.

[0057] Press bending: Place the front axle straight blank flat as follows Figure 11 The front axle is initially positioned on the lower die of the bending die, with both ends facing downwards. The flash generated during roll forging is used to engage the edge groove of the lower die for initial positioning, preventing the front axle from slipping or tilting. Then, the upper die presses down, bending both ends of the front axle downwards and the middle section upwards. During this process, the groove in the upper die accommodates the entire front axle section (mainly the section between the two steel plate positions), preventing the front axle from shifting during bending. The arc-shaped protrusions at both ends of the lower die, higher than the plane of the steel plate positions, ensure a larger bending radius on the inner side of the bend at both ends of the front axle, preventing wrinkles. The bent blank after pressing is as follows... Figure 6 As shown, the shape of the bent blank must closely match the final forging die. The receiving groove of the bending die has a uniform width along the length of the bending die or is designed differently, such as widening or narrowing the width of the receiving groove in local sections along the length direction; in addition, the receiving groove of the lower die of the bending die runs through its entire length, while the upper die only has receiving grooves at both ends and in the middle. The end of the upper and lower dies of the bending die used to receive the forging jaws does not have a receiving groove.

[0058] Final forging step 1: Place the bent billet into... Figure 12 and Figure 13 In the final forging die shown, on a 16000T pressure equipment, the final shape and size of the two steel plate positions and the middle section of the front axle of the mining truck are first formed (the fine parts can be placed in the second final forging). The die forms the middle cavity of the two steel plate positions and the middle section of the front axle, conforming to the shape and size of the finished front axle. The cavities at both ends of the die are symmetrical, conforming to the shape of the non-clamping end of the bent billet, and are slightly smaller in size. The parts other than the two ends of the two steel plate positions in the first final forging undergo simple deformation, and the jaws that were not deformed during roll forging are formed to the same shape and size as the fist of the non-clamping end. The formed forging is as follows: Figure 7 As shown.

[0059] Final Forging Part Two: Place the forging from the final forging die into... Figure 12 and Figure 13 In the final forging die shown, the final shape and dimensions of the portion of the mining truck front axle excluding the two ends of the two steel plates are symmetrically formed on a 16000T pressure machine. Simultaneously, the middle portion of the front axle is partially finished. The die cavity conforms to the shape and dimensions of the finished mining truck front axle. The forged part is as follows: Figure 8 As shown.

[0060] In the second step of segmented roll forging, and in both the final forging dies (partition plane of the front axle of the mining truck), the flash generated on this parting plane after forging is as follows: from the main body of the forging outwards, the flash from final forging dies (partition plane 2), final forging dies (partition plane 1), and roll forging flash. The roll forging flash is distributed on the inner and outer sides of the three bends of the forging, while the flash from final forging dies (partition plane 1 and partition plane 2) surrounds the entire main body of the forging. The final formed flash on the outer side of the forging is as follows: Figure 8 As shown.

[0061] Trimming: To reduce trimming pressure and achieve a neat cut, this embodiment trims the flash on the full-size blanking die. The trimming blade of the blanking die uses a beveled edge with a wavy shape, such as... Figure 14 and Figure 15 As shown.

[0062] Hot straightening: On a high-speed forging hydraulic press, a flat straightening method is used to straighten and locally shape the blank after the edges are cut.

[0063] After heat correction, the front axle undergoes heat treatment, shot blasting, flaw detection, inspection, and cold correction to finally obtain the finished mining truck front axle. The finished product exhibits excellent dimensional control, good overall consistency, and well-controlled mechanical properties within the range of 880-1030 MPa. Compared to steel plate welded front axles, this embodiment reduces the weight of the mining truck front axle by 64% and reduces production losses. Whether from a safety or economic perspective, this embodiment of the mining truck front axle is far superior to existing welded front axles, without requiring additional equipment investment from the company.

[0064] Because the mining truck front axle in this embodiment is extra-long, extra-wide, and extra-heavy, its production under existing conventional front axle production line conditions requires not only breaking it down into smaller parts and forming it in sections to reduce pressure requirements, but also ensuring seamless connection between each process. In particular, the shape of the forging after each process must match the mold cavity requirements of the next process as closely as possible, while the cross-sectional dimensions must have sufficient allowance without being excessive, in order to reduce material waste. The degree of forming in each process is determined by comprehensively considering equipment conditions and the metal deformation limit, through theoretical calculations and simulations, and after multiple experiments, to finally obtain the forging process of this embodiment, striving to produce qualified mining truck front axle forgings with as few processes as possible.

[0065] In addition, to better control the forging process and reduce the impact of flash on the forging process, the molds for final forging one and final forging two are designed as follows in this embodiment:

[0066] 1) The cavity used for forming forgings is designed with a negative deviation, that is, the sum of the cavity depths of the upper and lower dies is 3-4 mm less than that of the finished forging; this design is for undervoltage compensation when the equipment is unreliable.

[0067] 2) The overlap area between the two dies is 60-120mm. That is, the main forming area of ​​the final forging die 2 extends 60-120mm towards the steel plate position based on the secondary forming area of ​​the final forging die 1, and the transition between the extended section and the two ends is smooth. The secondary forming area refers to the area that does not deform or only deforms slightly.

[0068] 3) The flash bridge design employs a larger flash groove with open ends. The flash groove is 50%–100% deeper than usual, and the flash width is 50% narrower than usual, except in areas that are difficult to fill. The final forging has a flash thickness of 5–10 mm within 10 mm of the forging body. The deeper flash groove (compared to the standard front axle) ensures that the upper and lower dies do not contact or only slightly contact the flash during die forging, avoiding die pressing or over-pressing of the flash and dispersing equipment pressure. The narrower flash groove prevents excessive metal overflow, thus avoiding excessive material loss.

[0069] 4) The flash bridge in the final forging stage only considers the forming area of ​​the first forging stage, while the flash bridge in the second forging stage needs to take into account both the first and second forging stages. That is, when setting the flash bridge in the mold for the second forging stage, the flash problem of the entire forging must be considered, including the impact of the flash generated in the first forging stage on the forming of the second forging stage, the flash generated outside the entire forging body in the second forging stage, and the need to thin the flash close to the forging body to facilitate trimming. Therefore, as a step in the final forming of the product, the flash bridge needs to be considered as a whole.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and for the convenience of describing the technical solutions, the front, back, left, right, top, middle, and bottom orientations are based on the accompanying drawings 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 manufacturing a front axle for a large-tonnage, wide-wheelbase mining truck, comprising the following process: blanking → heating → step-by-step roll forging → bending → segmented final forging → edge trimming → hot straightening → heat treatment → shot blasting → flaw detection → inspection and cold straightening; wherein, Step-by-step roll forging: Using a φ1000 roll forging machine, one end of the round steel is clamped. In the first step, integral roll forging is performed. After the round steel is clamped by the roll forging die near the jaws, it is rolled while being pulled back, achieving initial metal distribution and widening of the two steel plate sections, so that the difficult-to-form steel plate sections can be formed by upsetting in subsequent processes. In the second step, segmented roll forging is performed. First, the roll forging die clamps the non-clamping end, and then the billet is pulled back. The non-clamping end of the billet is rolled, and the rolling length accounts for 1 / 4 to 1 / 3 of the total length. Then, the roll forging die clamps the clamping end close to the jaws, and then the billet is pulled back. The remaining section of the billet is rolled, and the rolling length accounts for 2 / 3 to 3 / 4 of the total length. Press bending: Using a hydraulic press or electric screw press, the blank is pressed and bent along the edges on a bending die that can contain the entire blank. Segmented final forging: Adopting the idea of ​​breaking down the whole into parts, first form the two steel plate positions of the front axle of the mining truck and the middle section between the two steel plate positions, and perform simple deformation on the parts other than the two ends of the two steel plate positions; then symmetrically form the part other than the two ends of the two steel plate positions, including the front axle fist, and perform finishing on the two steel plate positions and the middle section between the two steel plate positions; the final shape and size of the front axle of the mining truck are obtained by two forming processes; Trimming: Trimming the flash on the full-size blanking die. The cutting edge of the blanking die is a beveled blade with a wavy shape. Hot straightening: On a high-speed forging hydraulic press, a flat straightening method is used to straighten and locally shape the blank after the edges are trimmed; The second step of roll forging uses two sets of roll forging dies. Each set of roll forging dies consists of two symmetrical upper and lower roll forging dies. The central angle of the first set of roll forging dies is 65° to 70°. The first set of roll forging dies rolls from the bend at one end of the front shaft to the fist at that end, including the fist. The central angle of the second set of roll forging dies is 225° to 235°. The second set of roll forging dies rolls from the fist at the other end of the front shaft to the starting rolling position of the first set of roll forging dies, excluding the fist, and 0 to 50 mm beyond the starting rolling position of the first set of roll forging dies. The dies for segmented final forging include a first forging die and a second forging die, as designed below: 1) The cavity used for forming forgings is designed with negative deviation, that is, the sum of the cavity depths of the upper and lower dies is 3 to 4 mm less than that of the finished forging; 2) The overlap area between the two molds is 60-120mm, with a smooth transition; 3) The edge bridge design uses a duct groove and is open at both ends.

2. The method for manufacturing a front axle of a large-tonnage, wide-wheelbase mining truck according to claim 1, characterized in that: The forging weighs 250KG, is made of 42CrMo, is 2502mm long, has a middle I-beam that is 180mm wide and 212mm high, and has a 120mm drop between the upper surface of the I-beam and the center of the two end fists. The front axle is not hollow, and the lower flange in the middle of the I-beam has a concave clearance groove. The web of the I-beam is 20mm thick, and the web thickness at the middle and end of the I-beam where the leaf spring seats are installed is 25-35mm thicker than other places.

3. The method for manufacturing a front axle of a large-tonnage, wide-wheelbase mining truck according to claim 1, characterized in that: In step-by-step roll forging, an auxiliary support is provided between the roll forging machine and the clamping position to support the billet and prevent it from bending downwards.

4. The method for manufacturing a front axle of a large-tonnage, wide-wheelbase mining truck according to claim 1, characterized in that: The front shaft straight billet that is finally formed by roll forging has a cross-sectional area of ​​each section that is 0 to 500 mm² larger than the corresponding cross-section of the final forging cavity.

5. The method for manufacturing a front axle of a large-tonnage, wide-wheelbase mining truck according to claim 1, characterized in that: The blank is bent with flash, and a vertical retaining groove is provided on the bending die. The retaining groove structure is a straight groove or an open groove with a draft angle, and the width of the retaining groove is 10-30mm.

6. The method for manufacturing a front axle of a large-tonnage, wide-wheelbase mining truck according to claim 1, characterized in that: The segmented final forging die includes a final forging die 1 and a final forging die 2. Both dies are full-size dies and are symmetrical from left to right.

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