Forging Process of Full Streamline Near Net Shape Front Axle Forgings

Abstract

The present invention relates to a forging forming process for a fully streamlined near-net-shape front axle forging in the technical field of forging front axle forgings. The forging material is non-quenched and tempered steel, and includes: a pre-forging process, through symmetrical layered drafting, the upper surface of the spring seat of the front axle pre-forging includes two first folded surfaces symmetrically distributed with the parting surface; a final forging process, through asymmetrical layered drafting, the pre-forging is final-forged, so that the upper surface of the spring seat of the final forging obtained includes a second folded surface and a third folded surface that form a drop at the parting surface, and the first folded surface, the second folded surface and the third folded surface all include two connected inclined surfaces with different draft angles; a trimming process, using the main pin, spring seat and the middle of the I-section of the final forging as the trimming starting points; a correction process, performing semi-closed hot and warm forging correction on the spring seat. Beneficial effect: The upper and lower surfaces of the spring seat of the front axle forging are directly leveled by hot and warm forging, and the assembly and use requirements can be met without mechanical processing, realizing the full streamline structure of the forging and the near-net-shape structure of the spring seat.

Description

Technical Field

[0001] The invention relates to the technical field of forging a front axle forging, in particular to a forging forming process of a full-streamline near-net-shape front axle forging. Background Art

[0002] As one of the important parts of the automobile, the front axle is responsible for load-bearing and steering functions in the entire vehicle, and the front axle spring seat is one of the core parts of the front axle processing, assembly and function realization.

[0003] Traditional front axle forgings are made of quenched and tempered steel. After quenching and tempering, the forgings are greatly deformed. The upper and lower surfaces of the spring seat retain the final forging draft angle, leaving a large amount of processing allowance, and need to be machined to meet the assembly and use requirements. At present, although the lower plane of the spring seat of the front axle forging can be directly leveled, the upper plane still needs to be machined to meet the assembly requirements. After the upper plane is machined, some metal streamlines will be destroyed, affecting the strength of the front axle. In particular, after the front axle forging is trimmed, there is a conventional trimming band on the upper plane of the spring seat. The trimming section is composed of collapsed angles, bright bands, fracture bands and burrs. The conventional trimming band will cause the upper plane of the spring seat to be leveled after the upper plane is leveled. After the spring seat is hot-forged and leveled, abnormal protrusions, depressions, longitudinal flash, and uneven edges will appear. The existing process technology is difficult to meet the requirements of assembly and use by directly hot-forging and leveling the upper and lower surfaces of the spring seat of the full-streamline near-net-shaped front axle forging without subsequent machining, and the dimensional accuracy of the forging and the appearance of the trimming band are poor in commercial quality. At the same time, there are problems such as the inconsistency between the forging inspection benchmark and the machining positioning benchmark, unstable processing quality caused by insufficient inspection accuracy, and low inspection and processing efficiency caused by long process flow. Summary of the invention

[0004] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a forging process for a fully streamlined near-net-shaped front axle forging, the material of the forging is non-quenched and tempered steel, and is used to solve the problem of poor dimensional accuracy and appearance of trimmed bands in the prior art of the front axle forging, especially the problem that the flat surface on the spring seat of the forging is leveled by hot and warm forging, and there are magnetic marks on the flaw detection, and abnormal protrusions, depressions, longitudinal flash, crooked edges and other defects, which cannot directly meet the assembly and use requirements. At the same time, the fully streamlined near-net-shaped front axle forging formed by precision forging using the process of the present invention can achieve the unification of the forging inspection datum and the machining positioning datum, ensure the forging inspection accuracy and machining quality, and improve the inspection and machining efficiency.

[0005] To achieve the above-mentioned and other related purposes, the present invention provides a forging process for a fully streamlined near-net-shape front axle forging, wherein the forging is made of non-quenched and tempered steel, and comprises the following steps:

[0006] Pre-forging process, by symmetrically layered drawing to make the upper surface of the spring seat of the front axle pre-forging include two first folded surfaces symmetrically distributed with respect to the parting surface, and the first folded surface includes a first inclined surface and a second inclined surface that are connected and have different drawing angles;

[0007] Final forging process, by asymmetrically layered drawing to perform final forging on the upper surface of the spring seat of the front axle pre-forging, so that a drop is formed at the parting surface on the upper surface of the obtained front axle final forging. The upper surface of the spring seat of the front axle final forging includes a second folded surface and a third folded surface that form a drop at the parting surface. The second folded surface includes a third inclined surface and a fourth inclined surface that are connected and have different drawing angles, and the third folded surface includes a fifth inclined surface and a sixth inclined surface that are connected and have different drawing angles;

[0008] Trimming process, by using the positioning inclined surface on the front axle final forging and the local flash lower die surface for trimming positioning, and using the kingpin part, spring seat part and the middle part of the I-beam part of the front axle final forging as the trimming starting points;

[0009] Straightening process, performing semi-closed hot die forging straightening on the spring seat of the front axle final forging after trimming.

[0010] Optionally, the first inclined surface is the inclined surface close to the parting surface, the second inclined surface is the inclined surface far from the parting surface, and the drawing angle of the first inclined surface is greater than that of the second inclined surface.

[0011] Optionally, the second folded surface and the third folded surface are respectively located in the final forging upper die and the final forging lower die. The third inclined surface and the fifth inclined surface are the inclined surfaces close to the parting surface, the fourth inclined surface and the sixth inclined surface are the inclined surfaces far from the parting surface, the drawing angles of the fourth inclined surface and the sixth inclined surface are equal, and the drawing angles of the fifth inclined surface, the fourth inclined surface and the third inclined surface increase in sequence.

[0012] Optionally, a seventh inclined surface is provided at the part of the spring seat back I-beam of the front axle final forging located in the final forging lower die, an eighth inclined surface is provided at the parts of the two end faces of the kingpin of the front axle final forging located in the final forging lower die, the positioning inclined surface includes the seventh inclined surface, the eighth inclined surface and the fifth inclined surface, a ninth inclined surface is provided at the part of the spring seat back I-beam of the front axle final forging located in the final forging upper die, an tenth inclined surface is provided at the parts of the two end faces of the kingpin of the front axle final forging located in the final forging upper die, and the ninth inclined surface, the tenth inclined surface and the third inclined surface serve as compensation inclined surfaces.

[0013] Optionally, in the trimming process, the final forging of the front axle is trimmed by a constant-temperature trimming die; the trimming die of the constant-temperature trimming die is provided with a blade edge having a undulating shape, and the undulating shape of the blade edge includes a plurality of wave crest segments and wave trough segments. The wave crest segments are arranged at positions corresponding to the kingpin, spring seat and the middle part of the I-shaped part of the final forging of the front axle at the top of the female die. Raised portions are provided on both sides of the middle part of the I-shaped part corresponding to the wave crest segment cavity, and raised portions are provided at both ends of the spring seat back I-shaped part corresponding to the wave crest segment. The wave trough segments are located between two wave crest segments, and the wave crest segments and the wave trough segments are smoothly transitioned by multiple curved surfaces.

[0014] Optionally, in the trimming process, the wave crest segments of the blade edge are matched and positioned with the kingpin, spring seat and the middle part of the I-shaped part of the final forging of the front axle, so that the final forging of the front axle is trimmed in a horizontal posture.

[0015] Optionally, in the trimming process, the multiple wave crest segments of the blade edge are in contact positioning with the positioning inclined surface, and the multiple raised portions of the wave crest segment are in contact positioning with the lower die surface of the flash corresponding to it, so that the lower die surface of the flash corresponding to the wave crest segment at the upper surface of the spring seat of the final forging of the front axle is suspended.

[0016] Optionally, in the trimming process, the trimming sequence of the final forging of the front axle starts simultaneously from the seventh inclined surface, the fifth inclined surface, the eighth inclined surface and the flash parts corresponding to the raised portions. First, the cutting of the third inclined surface is completed, then the cutting of the ninth inclined surface and the tenth inclined surface is completed, and finally the cutting of the remaining flash is completed.

[0017] Optionally, the top angles of the spring seats of the pre-forging of the front axle and the final forging of the front axle are both outwardly convex arc structures, and the two side surfaces of the spring seats of the pre-forging of the front axle and the two side surfaces of the spring seats of the final forging of the front axle are both inwardly concave arc structures.

[0018] Optionally, in the straightening process, the trimmed final forging of the front axle is semi-closed hot temperature forging straightened by a straightening die; the straightening die includes a movable insert block, a fixed insert block and a spring seat press head. The movable insert block and the fixed insert block are cooperatively enclosed to form a straightening cavity for accommodating the spring seat. The spring seat press head is located above the movable insert block and the fixed insert block, and cooperates with the movable insert block and the fixed insert block to extrude the spring seat in the straightening cavity for semi-closed hot temperature forging straightening precision forming.

[0019] As described above, the forging process of the full streamline near-net shaped front axle forging of the present invention has at least the following beneficial effects: The material of the forging is non-quenched and tempered steel, and the hardness after controlled cooling is uniform with small deformation. By improving the forming structure of the front axle forging in the pre-forging process and the final forging process, changing the deformation form of the spring seat and the surrounding materials, reducing the change of the spring seat, the consistency of the shape and size of the front axle final forging is beneficial to balancing the material volume of the final forging process and the calibration process, ensuring that the edge of the spring seat is straight and the fillet is full after semi-closed hot warm forging calibration, without abnormal defects such as sharp corners, protrusions, depressions and longitudinal flash. Positioning inclined planes and compensation inclined planes are pre-set on the front axle final forging, matching the large undulating wavy curved surface structure of the trimming die, using the positioning inclined planes and the lower die surface of the local flash for positioning, improving the trimming stress state, trimming sequence and process, the trimming positioning attitude is stable, and the trimming process is smooth and stable, so that the bright trimming band on the upper surface of the spring seat reaches 95% or more of the trimming band area, and there is no magnetic flaw display in the trimming band covered after hot warm forging leveling. Finally, the shape, dimensional accuracy and appearance commodity of the trimming band of the forging are improved. Especially, after trimming the upper and lower surfaces of the spring seat, it is directly hot warm forged and leveled, and it can directly meet the assembly and use requirements without mechanical processing, realizing that the metal streamline is consistent with the forging shape, retaining integrity, improving the strength of the front axle. At the same time, the near-net shaped structure of the spring seat realizes the unity of the forging detection reference and the machining reference, ensures the forging detection accuracy and machining quality, improves the detection and machining efficiency, and helps to realize the light weight of the forging and improve the material utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It shows a schematic structural diagram of a full streamline near-net shaped front axle forging;

[0021] Figure 2 It shows Figure 1 The cross-sectional view of the full streamline near-net shaped front axle forging in

[0022] Figure 3 It shows Figure 1 The partial schematic diagram of the front axle pre-forging of the full streamline near-net shaped front axle forging in the pre-forging process in

[0023] Figure 4 It shows a schematic structural diagram of the pre-forging lower die of the pre-forging die;

[0024] Figure 5 It shows Figure 1 The schematic structural diagram of the front axle final forging of the full streamline near-net shaped front axle forging in the final forging process in

[0025] Figure 6 It shows Figure 5 The schematic structural diagram of the spring seat in

[0026] Figure 7 It showsFigure 5 Schematic diagram of the structure of the kingpin;

[0027] Figure 8 Schematic diagram of the structure of the finish forging lower die shown as the finish forging die;

[0028] Figure 9 Schematic diagram of the structure of the trimming die cavity shown as the trimming die;

[0029] Figure 10 Shown as Figure 9 Schematic diagram of the state of the cutting edge of the trimming die cavity and the spring seat at the initial trimming position;

[0030] Figure 11 Shown as Figure 9 Schematic diagram of the state of the cutting edge of the trimming die cavity and the kingpin at the initial trimming position;

[0031] Figure 12 Schematic diagram of the state of the cutting edge of the die cavity of the traditional trimming die and the spring seat at the initial trimming position;

[0032] Figure 13 Schematic diagram of the structure of the spring seat after the calibration process of the fully streamlined near-net-shaped front axle forging;

[0033] Figure 14 Schematic diagram of the structure of the calibration die;

[0034] Figure 15 Schematic diagram of the comparison of the trimming bands on the upper surfaces of the spring seats of the traditional front axle forging and the spring seat of the fully streamlined near-net-shaped front axle forging of the present application.

[0035] Description of part numbers

[0036] 100 - Front axle forging; 101 - Kingpin; 1011 - Eighth inclined surface; 1012 - Tenth inclined surface; 102 - Bent arm; 103 - Spring seat; 1031 - Upper surface of spring seat; 1032 - First folded surface; 1032a - First inclined surface; 1032b - Second inclined surface; 1033 - Second folded surface; 1033a - Third inclined surface; 1033b - Fourth inclined surface; 1034 - Third folded surface; 1034a - Fifth inclined surface; 1034b - Sixth inclined surface; 1035 - Seventh inclined surface; 1036 - Arc structure; 1037 - Ninth inclined surface; 104 - I-shaped part; 1041 - Web; 105 - Flash; 1051 - Lower die surface of flash; 201 - Finish forging lower die; 2011 - Clamping and positioning boss; 2012 - Finish forging lower die cavity; 2013 - Resistance retaining wall; 2014 - Variable flash bridge surface; 301 - Trimming die; 3011 - Edge; 3011a - Peak section; 3011b - Trough section; 3011c - Protrusion; 3012 - Die cavity; 401 - Movable insert; 402 - Fixed insert; 403 - Spring seat punch; 404 - Calibration cavity; 501 - Burr; 502 - Fracture zone; 503 - Bright zone; 504 - Corner break; 601 - Pre-forging lower die. Detailed implementation mode

[0037] The following uses specific specific examples to illustrate the implementation mode of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0038] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components during actual implementation. The type, quantity, and proportion of each component during actual implementation can be arbitrarily changed, and the component layout type may also be more complex. The structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration, rather than used to limit the scope under which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope under which the present invention can be implemented.

[0039] Before describing the embodiments of the present invention in detail, the application environment of the present invention will be described first. As Figure 1 and Figure 2 shown, the forging process of the present application is only applied to the full-streamline near-net-shaped front axle forging of non-quenched and tempered steel forging. The controlled cooling forging has uniform hardness, high strength and small deformation. The front axle forging 100 of this type includes a kingpin 101, a bent arm 102 and an I-beam part 103. The total length L of the forging can reach 1.8 m or more, and the thickness D of the web 1041 of the I-beam part 104 does not exceed 12 mm. The upper and lower surfaces of the spring seat of the front axle forging 100 forged by the forging process of the present application are directly hot-temperature forged and leveled, and can meet the assembly and use requirements without subsequent machining; and there are no abnormal protrusions, depressions, longitudinal flash and other defects on the appearance, the edges are straight and the fillets are full; there is no magnetic flaw display in the trimming band on the upper surface 1031 of the spring seat; the metal streamline conforms to the forging shape and is kept intact. The full-streamline structure of the forging and the near-net-shaped structure of the spring seat are realized. The technical problems that cannot be solved by the traditional forging process are solved.

[0040] See Figures 1 to 7 , in one embodiment, the present application provides a forging process for a full-streamline near-net-shaped front axle forging, including the following processes: a pre-forging process, a final-forging process, a trimming process and a straightening process.

[0041] Optionally, in the pre-forging process, by symmetrically layered drawing, the upper surface of the spring seat of the front axle pre-forging includes two first folding surfaces 1032 symmetrically distributed with respect to the parting surface. The first folding surface 1032 includes a first inclined surface 1032a and a second inclined surface 1032b that are connected and have different drawing angles.

[0042] Optionally, in the final-forging process, the upper surface of the spring seat of the front axle pre-forging is finally forged by asymmetrically layered drawing, so that a drop is formed at the parting surface on the upper surface of the obtained front axle final-forging. The upper surface of the spring seat of the front axle final-forging includes a second folding surface 1033 and a third folding surface 1034 that form a drop at the parting surface. The second folding surface 1033 includes a third inclined surface 1033a and a fourth inclined surface 1033b that are connected and have different drawing angles. The third folding surface 1034 includes a fifth inclined surface 1034a and a sixth inclined surface 1034b that are connected and have different drawing angles.

[0043] Optionally, in the trimming process, trimming positioning is performed through the positioning inclined surface on the front axle final-forging and the local flash lower die surface, and the kingpin position, spring seat position and the middle section of the I-beam part of the front axle final-forging are used as the trimming starting points.

[0044] Optionally, in the straightening process, semi-closed hot-temperature forging straightening is performed on the front axle final-forging after trimming.

[0045] Optionally, the forging process of the full streamline near-net shaped front axle forging further includes a roll forging process, a bending process, and a controlled cooling process. Among them, the roll forging process, the bending process, the pre-forging process, the final forging process, the trimming process, the sizing process, and the controlled cooling process are carried out in sequence.

[0046] It can be understood that the forging obtained after pre-forging in the pre-forging process can be called the front axle pre-forging, and the forging obtained after final forging in the final forging process can be called the front axle final forging. Both the front axle pre-forging and the front axle final forging have kingpins, bent arms, spring seats, and I-beams, but the shapes of each part are different in different processes.

[0047] In the forging process of the full streamline near-net shaped front axle forging in the above embodiment, by reasonably matching the forming shapes of the front axle pre-forging in the pre-forging process and the front axle final forging in the final forging process, gradually changing the deformation form of the spring seat and the surrounding materials, and strengthening the cavities of the pre-forging die and the final forging die, the deformation and wear of the die can be minimized, the change of the spring seat can be reduced, the consistency of the shape and size of the front axle final forging can be ensured, and it is beneficial to balance the material volume of the final forging process and the sizing process.

[0048] See Figures 1 to 7 , in an embodiment, the first inclined surface 1032a is an inclined surface close to the parting surface, the second inclined surface 1032b is an inclined surface far from the parting surface, the draft angle c of the first inclined surface 1032a is greater than the draft angle d of the second inclined surface 1032b, that is, the slope of the first inclined surface 1032a is greater than the slope of the second inclined surface 1032b, which is beneficial to improving the material filling property of the spring seat part.

[0049] See Figures 1 to 7 , in an embodiment, the second folding surface 1033 and the third folding surface 1034 are respectively located in the final forging upper die and the final forging lower die. The third inclined surface 1033a and the fifth inclined surface 1034b are inclined surfaces close to the parting surface, and the fourth inclined surface 1033b and the sixth inclined surface 1034b are inclined surfaces far from the parting surface; the draft angles b of the fourth inclined surface 1033b and the sixth inclined surface 1034b are equal, that is, the slopes of the fourth inclined surface 1033b and the sixth inclined surface 1034b are equal; the draft angles of the fifth inclined surface 1034a, the fourth inclined surface 1033b, and the third inclined surface 1033a increase in sequence. The draft angle a2 is less than the draft angle b, the draft angle b is less than the draft angle a1, and the slopes of the fifth inclined surface 1034a, the fourth inclined surface 1033b, and the third inclined surface 1033a increase in sequence.

[0050] Optionally, the draft angle d of the second inclined surface 1032b formed by the front axle forging in the pre-forging process is equal to the draft angle b of the fourth inclined surface 1033b and the sixth inclined surface 1034b formed in the final forging process, that is, the slope of the second inclined surface 1032b is equal to the slopes of the fourth inclined surface 1033b and the sixth inclined surface 1034b.

[0051] Optionally, the draft angle c of the first inclined surface 1032a formed in the pre-forging process of the front axle forging is greater than the draft angle a1 of the third inclined surface 1033a and the draft angle a2 of the fifth inclined surface 1034a formed in the final forging process, that is, the slope of the first inclined surface 1032a is greater than the slope of the third inclined surface 1033a and the slope of the fifth inclined surface 1034a. Further, the draft angle a1 of the third inclined surface 1033a is reduced by 1° to 3° on the basis of the draft angle c of the first inclined surface 1032a, which is conducive to slowing down the violent degree of material flow at the spring seat parting surface in the front axle final forging process, improving the filling property of the spring seat part in the final forging process, and can minimize the deformation and wear of the die, reduce the change of the spring seat, make the front axle final forging consistent, and help balance the material volume of the final forging process and the correction process, and ensure that the edges of the spring seat are straight and the rounded corners are full after the semi-closed hot and warm forging correction, without abnormal defects such as sharp corners, protrusions, depressions and longitudinal flash.

[0052] See also Figures 1 to 12 In one embodiment, the spring seat back I-shaped portion of the front axle final forging is provided with a seventh inclined surface 1035 at the position located in the forging lower die, and the two end surfaces of the kingpin 101 of the front axle final forging are provided with an eighth inclined surface 1011 at the position located in the final forging lower die. The positioning inclined surfaces include the seventh inclined surface 1035, the eighth inclined surface 1011 and the fifth inclined surface 1034a. The spring seat back I-shaped portion of the front axle final forging is provided with a ninth inclined surface 1037 at the position located in the final forging upper die, and the two end surfaces of the kingpin of the front axle final forging are provided with a tenth inclined surface 1012 at the position located in the final forging upper die. The ninth inclined surface, the tenth inclined surface and the third inclined surface serve as compensation inclined surfaces.

[0053] Optionally, in the trimming process, the front axle final forging is trimmed by a constant temperature trimming die. The trimming die 301 of the constant temperature trimming die is provided with a cutting edge 3011 with an undulating shape, and the undulating shape of the cutting edge 3011 includes a plurality of wave crest sections 3011a and wave trough sections 3011b. The wave crest section 3011a is arranged at the top of the die corresponding to the main pin, spring seat and the middle of the I-section of the front axle final forging, and protrusions 3011c are arranged on both sides of the cavity corresponding to the wave crest section in the middle of the I-section, and protrusions 3011c are arranged at both ends of the I-section corresponding to the wave crest section on the back of the spring seat, and the protrusions 3011c are used for auxiliary support, and the wave trough section 3011b is located between the two wave crest sections, and the wave crest section and the wave trough section adopt a multi-section curved surface for smooth transition.

[0054] It can be understood that the front axle forging obtained after the final forging process is completed has a flash 105 on the front axle forging, and the flash 105 is located at the parting surface.

[0055] Optionally, in the trimming process, the peak segments of the cutting edge are positioned in cooperation with the kingpin, spring seat and the middle section of the I-beam of the front axle finish forging, so that the front axle finish forging is trimmed in a horizontal posture. During trimming, the kingpin position, spring seat position and the middle part of the I-beam of the front axle finish forging are used as the trimming starting points, and the overall shearing state is progressive cross shearing, that is, extending from the peak segment to the periphery to the valley segment, so that the trimming starting positions are in a dispersed state. Among them, the peak segments corresponding to the kingpin position and the spring seat position in the cutting edge have both positioning and balancing functions at the same time, and the peak segment corresponding to the I-beam mainly has a balancing function. Each peak segment cooperates to ensure a stable trimming resistance, change the trimming stress state, trimming sequence and process, balance, disperse and reduce the trimming resistance, make the trimming process smooth and stable, and at the same time increase the trimming stroke, so that the bright trimming band on the upper surface of the spring seat is formed in the smooth trimming stroke section, improving the trimming quality, especially the proportion of the bright trimming band on the upper surface of the spring seat is increased to more than 95%, ensuring that there is no magnetic flaw display in the trimming band covered after hot temperature forging leveling of the upper plane of the spring seat; the cutting edge with a undulating shape can also avoid direct large-area contact between the front axle finish forging and the cutting edge, prevent the cutting die from heating up too fast, slow down the failure of the cutting edge and extend the service life.

[0056] Optionally, in the trimming process, multiple peak segments of the cutting edge are in contact with the positioning inclined plane to form the main trimming positioning. The protrusions 3011c on both sides of the cavity of the peak segment corresponding to the middle part of the I-beam and the protrusions 3011c at both ends of the peak segment corresponding to the spring seat back I-beam contact with the corresponding flash lower die surface 1051 to form auxiliary positioning together, so that the flash lower die surface 1051 corresponding to the peak segment of the cutting edge at the upper surface of the spring seat of the finish forging is suspended. The positioning method of the front axle forging in the traditional trimming process is changed, and it is ensured that the front axle finish forging is horizontally placed on the die, improving the positioning accuracy in the horizontal plane, making the positioning posture of the front axle finish forging stable during the trimming process, and providing a basis for the smooth and stable trimming process. Further, the distance between the flash lower die surface 1051 and the cutting edge at the upper surface of the spring is H, and the distance H can be about 10 mm.

[0057] Optionally, in the trimming process, the trimming form of the main part is that the cutting edge wave crest section cutting edge corresponding to the kingpin and spring seat parts cooperates with the positioning inclined plane and compensation inclined plane of the front axle finish forging to perform trimming, so that the trimming sequence of the upper surface part of the spring seat, the back I-shaped part of the spring seat, and the two end face parts of the kingpin is the positioning inclined plane, flash, and compensation inclined plane in sequence. The trimming sequence and process are that the cutting edges of multiple wave crest sections contact the positioning inclined plane of the process compensation of the front axle finish forging simultaneously, and the protrusion contacts the flash lower die surface of its corresponding part simultaneously to start trimming. First, complete the trimming of the upper surface part of the spring seat, then complete the trimming of the back I-shaped part of the spring seat and the two end face parts of the kingpin, and finally complete the trimming of the remaining parts until all trimming processes are completed, that is, the trimming sequence starts simultaneously from the flash parts corresponding to the seventh inclined plane, fifth inclined plane, eighth inclined plane, and protrusion. First, complete the cutting of the third inclined plane, then complete the cutting of the ninth inclined plane and the tenth inclined plane, and finally complete the cutting of the remaining flash. Adjust the trimming sequence and process of each part of the front axle finish forging to balance the trimming resistance, make the trimming process smooth and stable, improve the trimming quality, especially ensure that the trimming process of the upper surface of the spring seat is carried out in a smooth and stable stroke section, form a trimming band with the required bright band ratio, and can greatly increase the proportion of the trimming bright band in the trimming band.

[0058] Optionally, the finish forging is provided with a trimming positioning inclined plane and a compensation inclined plane at the kingpin and spring seat parts. Specifically: the positioning inclined plane includes the spring seat upper surface positioning inclined plane (the fifth inclined plane 1034a) arranged on the lower die of the upper surface of the spring seat, the spring seat back I-shaped part boss positioning inclined plane (the seventh inclined plane 1035) arranged on the lower die of the back I-shaped part of the spring seat, and the kingpin end face positioning inclined plane (the eighth inclined plane 1011) arranged on the lower die of the two end faces of the kingpin. The compensation inclined plane includes the spring seat upper surface compensation inclined plane (the third inclined plane 1033a) arranged on the upper die of the upper surface of the spring seat, the spring seat back I-shaped part boss compensation inclined plane (the ninth inclined plane 1037) arranged on the upper die of the back I-shaped part of the spring seat, and the kingpin end face compensation inclined plane (the tenth inclined plane 1012) arranged on the upper die of the two end faces of the kingpin.

[0059] In the above trimming process, the fifth inclined plane 1034a of the lower die of the upper surface of the spring seat and the third inclined plane 1033a of the upper die are removed by trimming and correction, so that the upper surface of the spring seat is directly hot leveled and can directly meet the requirements of assembly and use without mechanical processing; the seventh inclined plane 1035 of the lower die of the back I-shaped part of the spring seat and the ninth inclined plane 1037 of the upper die are located in a very small area of the non-machined surface of the front axle forging and remain in the forging finished product; the eighth inclined plane 1011 of the lower die of the two end faces of the kingpin and the tenth inclined plane 1012 of the upper die are located on the machined surface and can be completely removed by mechanical processing. The above trimming positioning inclined plane and trimming compensation inclined plane of process compensation do not affect the structural strength, machining, assembly and use performance, and appearance commodity of the front axle forging.

[0060] Optionally, in the trimming process, by arranging a die cooling water channel inside the female die and a punch cooling water channel inside the male die, a cooling medium can be introduced into the die, making the die temperature low, with small temperature fluctuations and relatively constant temperature, and the shape, size, and gap are more stable, so that the length change of the trimming die along the length direction of the front axle finish forging due to die temperature fluctuations is less than 1 mm; by reducing the temperature change during the working process of the trimming die, reducing the size fluctuation of the trimming die, and performing controlled cooling on the front axle forging made of non-quenched and tempered steel, the deformation of the front axle forging can be reduced, thereby ensuring the stability of the front axle forging size and improving the trimming quality, making the trimming quality of special trimming parts continuously stable.

[0061] See Figure 3 and Figure 6 , in one embodiment, the side top angles of the spring seats of the front axle pre-forging and the front axle finish forging are both outwardly convex arc structures 1036, and the middle parts of both side surfaces of the spring seats of the front axle pre-forging and the middle parts of both side surfaces of the spring seats of the front axle finish forging are both inwardly concave arc structures 1036. The two sides of the spring seat of the front axle pre-forging adopt a structure with four outwardly convex top angles and an inwardly concave middle, which is beneficial to improving the filling property of the side surface of the spring seat in the pre-forging process, especially the filling property of the difficult-to-fill parts at the four corners of the side surface of the spring seat; the front axle pre-forging matches the finish forging cavity, which is also beneficial to the material filling in the finish forging process. The two sides of the spring seat of the front axle finish forging adopt a structure with four outwardly convex top angles and an inwardly concave middle, which is beneficial to improving the filling property of the side surface of the spring seat in the finish forging process, especially the filling property of the difficult-to-fill parts at the four corners of the side surface of the spring seat, and is beneficial to balancing the material volume of the finish forging process and the calibration process, ensuring that the edges of the spring seat are straight and the fillets are full after semi-closed hot die forging calibration, without abnormal defects such as sharp corners, protrusions, depressions, and longitudinal flash.

[0062] See Figure 4 and Figure 8 , in one embodiment, the pre-forging lower die 601 is provided with resistance retaining walls 2013 on both sides of the spring seat cavity and around the kingpin cavity, and the finish-forging lower die 201 is provided with resistance retaining walls 2013 on one side of the upper surface of the spring seat in the spring seat cavity, changing the local metal flow mode, slowing down the severity of the local metal flow, improving the filling property, minimizing die deformation and wear, making the shape and size of the front axle finish forging have good consistency, and being beneficial to balancing the material volume of the finish forging process and the calibration process.

[0063] See Figure 8 , in one embodiment, the finish-forging lower die 201 adopts a variable flash bridge surface 2014 design on both sides of the spring seat cavity and around the kingpin cavity, changing the local metal flow resistance, and matching reasonable forging parameters helps to control the dimensional accuracy in the thickness direction of the forging.

[0064] See Figure 4 and Figure 8, in one embodiment, a plurality of clamping and positioning bosses 2011 are convexly provided on one side of the final forging lower die 201 facing the final forging upper die, and the plurality of clamping and positioning bosses 2011 are symmetrically distributed on both sides of the final forging lower die cavity 2012; the manipulator jaw and the front axle final forging are designed as an integral body. By providing the clamping and positioning bosses 2011 to form a manipulator clamping position on the flash of the final forging, it is convenient for the manipulator jaw to pick and place the workpiece, ensuring accurate workpiece gripping position in the final forging process, stable transfer between processes, and accurate workpiece placing position in the trimming process, which is beneficial to the stability of the trimming attitude of the final forging.

[0065] See Figure 13 and Figure 14 , in one embodiment, in the straightening process, the spring seat of the trimmed front axle forging is subjected to semi-closed hot die forging straightening precision forming through a straightening die to obtain the final near-net-shaped forging structure. Adopting semi-closed hot die forging straightening is beneficial to ensuring the near-net-shaped quality of the spring seat.

[0066] Optionally, the straightening die includes a movable insert 401, a fixed insert 402, and a spring seat punch 403. The movable insert 401 and the fixed insert 402 cooperate to enclose a straightening cavity 404 for accommodating the spring seat. The spring seat punch 403 is located above the movable insert 401 and the fixed insert 402 and cooperates with the movable insert 401 and the fixed insert 402 to extrude the spring seat in the straightening cavity 404 for semi-closed hot die forging straightening.

[0067] By adopting semi-closed hot die forging straightening, the straightened front axle forging meets the following requirements: the flatness of the upper surface of the spring seat ≤ 0.8, the flatness between the upper surfaces of the two side spring seats ≤ 1.5, the parallelism between the upper surface and the lower surface ≤ 1.3, the edges of the spring seat are straight, the fillets are full, and there are no abnormal defects such as sharp corners, protrusions, depressions, and longitudinal flashes, ensuring the near-net-shaped quality of the spring seat.

[0068] See Figure 4 and Figure 8, when the front axle forging is in the initial state of the traditional trimming process, the cutting edge contacts the flash directly and starts trimming immediately. After trimming, the proportion of the bright trimming band in the trimming band on the upper surface of the spring seat is small, which will not only cause magnetic flaw detection marks to appear after the upper surface of the spring seat is leveled, but also when leveling the upper and lower surfaces of the spring seat, if the volume of the final forging material is too small, the edge will be not straight and there will be abnormal depressions, and if the volume is too large, there will be longitudinal flash, abnormal protrusions, and sharp corners. The matching difficulty between the final forging process and the calibration process is great, and only through machining can the assembly and use requirements be met. Machining the upper surface of the spring seat will damage part of the metal streamline and affect the service strength of the front axle. Compared with the front axle forging obtained by the traditional process, the burr 501, fracture zone 502, bright band 503, and corner break 504 of the front axle forging obtained by the forging forming process of the present application have obvious changes. Among them, the present application ensures that there is no residue and no burr after trimming the upper plane of the spring seat, and the cut is smooth, without abnormal protrusions and pits with sharp changes. The area proportion of the trimming bright band 503 in the trimming band is as high as 95% or more, meeting the requirement of no magnetic flaw detection marks for the trimming band covered after leveling the upper plane of the spring seat. Specifically, the burr band H2, fracture zone F2, and corner break R2 of the front axle forging of the present application are significantly reduced compared with the traditional burr band H1, fracture zone F1, and corner break R1, while the proportion of the bright band B2 of the front axle forging of the present application in the trimming band is greatly increased compared with the traditional bright band B1, ensuring no magnetic flaw detection marks for the trimming band covered after hot temperature forging leveling of the upper plane of the spring seat.

[0069] The full-streamline near-net-shaped front axle forging of this application is forged from non-quenched and tempered steel, with uniform hardness and small deformation during controlled cooling. By reasonably matching the forming shapes of the front axle pre-forging in the pre-forging process and the front axle final forging in the final forging process, gradually changing the deformation form of the spring seat and the surrounding materials, and strengthening the cavities of the pre-forging die and the final forging die, the die deformation and wear can be minimized, the change of the spring seat can be reduced, and the consistency of the shape and size of the front axle final forging is beneficial to balancing the material volume of the final forging process and the straightening process, ensuring that the edges of the spring seat are straight and the fillets are full after semi-closed hot warm forging straightening, without abnormal defects such as sharp corners, protrusions, depressions, and longitudinal flash. At the same time, a positioning inclined plane and a compensation inclined plane are preset on the front axle final forging, matching the large undulating wavy curved surface structure of the concave die of the constant-temperature trimming die, using the positioning inclined plane and the lower die surface of the local flash for positioning, improving the trimming stress state, trimming sequence, and process, balancing, dispersing, and reducing the trimming resistance, with a stable trimming positioning attitude and a smooth and stable trimming process, so that the bright trimming band on the upper surface of the spring seat reaches 95% or more of the trimming band area, and there is no magnetic flaw display in the trimming band covered after hot warm forging leveling. Finally, the dimensional accuracy of the front axle forging and the appearance commerciality of the trimming band are improved. In particular, the upper and lower surfaces of the spring seat of the front axle forging are directly hot warm forged and leveled, meeting the assembly and use requirements without mechanical processing, with the metal streamline conforming to the forging shape and remaining intact, enhancing the strength of the front axle. At the same time, the near-net-shaped structure of the spring seat realizes the unity of the forging inspection reference and the mechanical processing reference, ensuring the forging inspection accuracy and mechanical processing quality, improving the inspection and mechanical processing efficiency, and contributing to the lightweight of the forging and the improvement of material utilization rate.

[0070] In the description of this specification, the descriptions referring to terms such as "this embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0071] The above embodiments are only illustrative of the principles and effects of the present invention and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A forging process for a full-streamline near-net-shaped front axle forging, the material of the forging being non-quenched and tempered steel, characterized in that, It includes the following processes: Pre-forging process, by symmetrically layered drawing to make the upper surface of the spring seat of the front axle pre-forging include two first folding surfaces symmetrically distributed with respect to the parting surface. The first folding surface includes a first inclined surface and a second inclined surface that are connected and have different drawing angles. The first inclined surface is the inclined surface close to the parting surface, and the second inclined surface is the inclined surface far from the parting surface. The drawing angle of the first inclined surface is greater than that of the second inclined surface; Final forging process, by asymmetrically layered drawing to perform final forging on the upper surface of the spring seat of the front axle pre-forging, so that a drop is formed at the parting surface on the upper surface of the spring seat of the obtained front axle final forging. The upper surface of the spring seat of the front axle final forging includes a second folding surface and a third folding surface that form a drop at the parting surface. The second folding surface includes a third inclined surface and a fourth inclined surface that are connected and have different drawing angles. The third folding surface includes a fifth inclined surface and a sixth inclined surface that are connected and have different drawing angles. The second folding surface and the third folding surface are respectively located in the final forging upper die and the final forging lower die. The third inclined surface and the fifth inclined surface are the inclined surfaces close to the parting surface, and the fourth inclined surface and the sixth inclined surface are the inclined surfaces far from the parting surface. The drawing angles of the fourth inclined surface and the sixth inclined surface are equal, and the drawing angles of the fifth inclined surface, the fourth inclined surface, and the third inclined surface increase in sequence; Trimming process, by using the positioning inclined surface on the front axle final forging and the local flash lower die surface for trimming positioning, and using the kingpin part, spring seat part, and the middle part of the I-beam part of the front axle final forging as the trimming starting points. There is a seventh inclined surface at the part of the spring seat back I-beam of the front axle final forging located in the final forging lower die, and there is an eighth inclined surface at the parts of the two end faces of the kingpin of the front axle final forging located in the final forging lower die. The positioning inclined surface includes the seventh inclined surface, the eighth inclined surface, and the fifth inclined surface. There is a ninth inclined surface at the part of the spring seat back I-beam of the front axle final forging located in the final forging upper die, and there is a tenth inclined surface at the parts of the two end faces of the kingpin of the front axle final forging located in the final forging upper die. The ninth inclined surface, the tenth inclined surface, and the third inclined surface serve as compensation inclined surfaces; Straightening process, performing semi-closed hot temperature forging straightening on the spring seat of the front axle final forging after trimming.

2. The forging process of the full-streamline near-net-shaped front axle forging according to claim 1, characterized in that: In the trimming process, the front axle final forging is trimmed by a constant temperature trimming die. The trimming die of the constant temperature trimming die is provided with a cutting edge with a undulating shape. The undulating shape of the cutting edge includes a plurality of peak segments and valley segments. The peak segments are arranged at the parts corresponding to the kingpin, spring seat, and the middle part of the I-beam of the front axle final forging at the top of the die. There are protrusions on both sides of the cavity corresponding to the peak segment of the middle part of the I-beam, and there are protrusions at both ends of the spring seat back I-beam corresponding to the peak segment. The valley segments are between two peak segments, and the peak segments and valley segments are smoothly transitioned by multi-segment curved surfaces.

3. The forging process of the full-streamline near-net-shaped front axle forging according to claim 2, characterized in that: In the trimming process, the peak segments of the cutting edge cooperate with the kingpin, spring seat, and the middle part of the I-beam of the front axle final forging for positioning, so that the front axle final forging is trimmed in a horizontal posture.

4. The forging process of the full streamline near-net-shaped front axle forging according to claim 2, characterized in that: In the trimming process, multiple peak segments of the cutting edge are in contact positioning with the positioning inclined surface, and multiple protrusions of the peak segments are in contact positioning with the trimming lower die surface corresponding thereto, so that the trimming lower die surface corresponding to the peak segment of the cutting edge is suspended at the upper surface of the spring seat of the front axle finish forging.

5. The forging process of the fully-streamlined near-net-shaped front axle forging according to claim 2 or 4, characterized in that: In the trimming process, the trimming sequence of the front axle finish forging starts simultaneously from the seventh inclined surface, the fifth inclined surface, the eighth inclined surface and the trimming part corresponding to the protrusion, first completes the cutting of the third inclined surface, then completes the cutting of the ninth inclined surface and the tenth inclined surface, and finally completes the cutting of the remaining trimming part.

6. The forging process of the fully streamlined near-net-shaped front axle forging according to claim 1, characterized in that: The spring seat apex angles of the front axle pre-forging and the front axle finish forging are both outwardly convex arc structures, and the two side surfaces of the spring seat of the front axle pre-forging and the two side surfaces of the spring seat of the front axle finish forging are both inwardly concave arc structures.

7. The forging process of the full-streamline near-net-shaped front axle forging according to claim 1, characterized in that: In the sizing process, the trimmed front axle finish forging is sized by semi-closed hot die forging using a sizing die; the sizing die includes a movable insert, a fixed insert and a spring seat press head. The movable insert and the fixed insert cooperate to enclose a sizing cavity for accommodating the spring seat. The spring seat press head is located above the movable insert and the fixed insert, and cooperates with the movable insert and the fixed insert to extrude the spring seat in the sizing cavity for semi-closed hot die forging sizing precision forming.

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