Manufacturing method for assembling and welding type double-rear-axle-set V-shaped thrust rod mounting base

Abstract

The invention relates to the technical field of thrust rod assembly, in particular to an assembly welding type double-rear-axle-set V-shaped thrust rod mounting base manufacturing method which comprises the following steps that S100, a bottom plate piece, a connecting piece, a first reinforcing piece and a second reinforcing piece are machined in a machining mode; s200, a first reinforcing piece and a second reinforcing piece are placed at preset positions of the upper surface of the bottom plate piece and welded according to a preset welding mode; s300, the connecting piece is placed on the upper surface of the bottom plate piece and located at a preset position between the first reinforcing piece and the second reinforcing piece, and welding is conducted according to a preset welding mode; through the arrangement, firstly, the precision of each part can be ensured, secondly, the production cost is reduced, the production efficiency is improved, and the problems of high mold opening cost and long manufacturing period of an existing integral molding casting mode are solved; and finally, the problem that the assembly position error of the component is too large due to thermal deformation in the welding process is solved.

Description

Technical Field

[0001] This invention relates to a method for preparing a V-shaped thrust rod mounting base for a welded double rear axle assembly, belonging to the field of thrust rod assembly technology. Background Technology

[0002] In heavy-duty vehicles equipped with dual rear axles, the V-type thrust rod is a key suspension guiding and force transmission element. It is firmly connected to the longitudinal and transverse beams of the frame through a mounting bracket. The main function of the V-type thrust rod is to precisely constrain the movement trajectory of the axle and bear and transmit complex loads from the vehicle during driving. The geometric accuracy, structural strength and long-term service reliability of its mounting bracket are directly related to the vehicle's handling stability, tire wear condition and even driving safety.

[0003] In existing technologies, common V-type thrust rod mounting seats are manufactured using a one-piece casting process. This manufacturing method has significant inherent defects. Its "one mold, one structure" characteristic leads to highly specialized molds. When dealing with axle assemblies or thrust rod specifications of different brands and models, or when producing small batches of special models, it is necessary to redesign and manufacture the entire set of molds. This results in high mold opening costs and lengthy production preparation cycles, which seriously restricts the production flexibility and market response speed of the products. Therefore, it is of great practical significance to study a new method for preparing a modular and welded V-type thrust rod mounting seat for dual rear axle groups. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing a V-shaped thrust rod mounting base for a welded dual rear axle assembly.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A method for preparing a V-shaped thrust rod mounting base for a welded double rear axle assembly, the preparation method comprising the following steps: S100: The base plate, connector, first reinforcing member, and second reinforcing member are machined separately. S200: Place the first reinforcing member and the second reinforcing member at predetermined positions on the upper surface of the base plate and weld them according to a predetermined welding method; S300: Place the connector on the upper surface of the base plate and at a predetermined position between the first reinforcing member and the second reinforcing member, and weld it according to a predetermined welding method.

[0006] Furthermore, step S200 also includes: S210: Completely weld the first reinforcing member to the base plate; S220: Spot weld two points between the second reinforcing member and the base plate member; Step S300 also includes: S310: Spot weld a point between the upper part of the first reinforcing member and the connecting member; S320: Weld the weld between the side of the connector near the second reinforcing member and the base plate member; S330: The second reinforcing member is sequentially and completely welded to the connecting member and the base plate member; S340: Weld the remaining weld between the connector and the base plate; S350: Weld the first reinforcing member to the connecting member completely.

[0007] Furthermore, the base plate is provided with two identical limiting holes that penetrate the base plate symmetrically relative to its central surface. The connector is an integral structure, including a first connecting part and a second connecting part symmetrically arranged relative to its central surface. The lower surface of the connector is provided with two rectangular protrusions adapted to the limiting block, symmetrically arranged relative to its central surface. When the connector is placed on the upper surface of the base plate, the rectangular protrusions are inserted into the corresponding limiting holes, and the two are clearance-fitted. The height of the rectangular protrusions is less than the depth of the limiting holes. Step S310 also includes: S311: Spot weld the midpoint of the bottom edge of the rectangular boss to the limiting hole; Step S350 also includes: S351: The rectangular boss is fully welded to the limiting hole, and the limiting hole area between the lower surface of the rectangular boss and the lower surface of the base plate is completely filled by welding.

[0008] Furthermore, the connector located in the area between the two rectangular bosses is not welded to the base plate.

[0009] Furthermore, the first connecting part and the second connecting part are symmetrically cut, and the upper mounting area is above the cut. The upper mounting area is provided with mounting holes for connecting the thrust rod, and the first mounting surface that abuts against the thrust rod has a first preset slope. Below the cut is the lower mounting area, which has mounting holes for connecting the thrust rod, and the second mounting surface that abuts against the thrust rod has a second preset slope; The bottom, upper, and lower sides of the cut are all flat. One end of the upper side is connected to the first mounting surface, and the other end is connected to the bottom surface through an arc. One end of the lower side is connected to the second mounting surface, and the other end is connected to the bottom surface through an arc. The upper and lower sides are arranged in parallel. The bottom surface has a third preset slope, and the first preset slope, the second preset slope, and the third preset slope are all equal.

[0010] Furthermore, the second mounting surface extends along a second preset slope and connects to the bottom side of the connector, and the outer side of the rectangular boss is flush with the bottom side of the connector.

[0011] Furthermore, the second mounting surface and the center surface of the connector have an included angle α; The lower side surface and the bottom surface of the connector have an included angle β; The relationship between α and β satisfies 2°≤β-α≤5°, and the value of α ranges from 20° to 25°.

[0012] Furthermore, the relationship between the distance L between the two rectangular bosses, the length S of the rectangular bosses, and the angle α between the second mounting surface and the center plane of the connector satisfies: In the formula, This is a correction factor, with a value ranging from 0.95 to 1.0; The standard included angle is 90°.

[0013] Furthermore, the intersection point of the extension line of the lower side along its length direction and the center surface of the connector is P0, the vertical distance from the intersection point P0 to the bottom surface of the connector is X1, and the relationship between X1 and the height X2 from the top surface to the bottom surface of the connector satisfies: X2 = (7.5-9)X1.

[0014] Furthermore, the relationship between the length S of the rectangular boss, the height H of the rectangular boss, and the depth G of the limiting hole satisfies S:H:G=1:(0.16-0.2):(0.22-0.25).

[0015] The beneficial effects of this invention are as follows: By disassembling the mounting base into multiple independent components, firstly, this method simplifies manufacturing. Machining effectively ensures the precision of each component, meeting the accuracy requirements during thrust rod installation. Secondly, it breaks the limitations of existing one-piece casting methods, which restrict the structure to a single mold. For special vehicle models or small-batch orders, there is no need to re-mold; only the dimensional parameters of one or a few components need to be changed to quickly adapt to bridge assemblies and thrust rods of different brands and models. This reduces production costs and improves production efficiency, solving the problems of high mold opening costs and long manufacturing cycles associated with existing one-piece casting methods. Finally, by optimizing the mounting base... The limitations imposed on the assembly and welding process effectively coordinate the deformation of various components and solve the problem of excessive assembly position errors caused by heat deformation during welding. By prioritizing the placement and welding of the first and second reinforcing members, a rigid positioning support frame is established on the base plate. This effectively absorbs and transfers welding heat and stress, thereby limiting warping caused by thermal expansion and contraction during subsequent welding of the base plate. It also provides effective boundary constraints on the connecting parts, preventing structural instability and excessive deformation after welding. This effectively controls the assembly position deviation of the connecting parts, ensuring that they meet the installation accuracy requirements of the V-shaped thrust rod of the dual rear axle assembly. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional structural diagram of the mounting base provided by the present invention; Figure 2 This is a three-dimensional structural diagram of the mounting base provided by the present invention from another perspective. Figure 3 This is an exploded view of the mounting base provided by the present invention; Figure 4 This is a three-dimensional structural diagram of the base plate component provided by the present invention; Figure 5 This is a three-dimensional structural diagram of the connector provided by the present invention; Figure 6 This is a front view of the connector provided by the present invention; Figure 7 This is a rear view of the connector provided by the present invention; Figure 8 for Figure 5 Enlarged view of the structure at point A in the middle.

[0018] Reference numerals: 1. Base plate; 11. Limiting hole; 2. Connector; 21. First connecting part; 22. Second connecting part; 23. Rectangular boss; 24. Cutout; 241. Bottom surface; 242. Upper side surface; 243. Lower side surface; 25. Upper mounting area; 251. First mounting surface; 26. Lower mounting area; 261. Second mounting surface; 27. Mounting hole; 3. First reinforcing member; 4. Second reinforcing member. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Furthermore, the terms "first," "second," and "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0022] In this invention, unless otherwise expressly specified and limited, "above or below" a first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] Example 1 like Figure 1-3 As shown, the present invention provides a method for preparing a V-shaped thrust rod mounting base for a welded dual rear axle assembly, the method comprising the following steps: S100: The base plate 1, connector 2, first reinforcing member 3, and second reinforcing member 4 are machined separately. It should be noted that the base plate 1 is used to connect the longitudinal beam of the frame, the connector 2 is used to connect the V-shaped thrust rod, and the first reinforcing member 3 and the second reinforcing member 4 have the same structure and are used to connect the cross beam of the frame. The precision of each component is ensured by machining. It is preferred to use a CNC milling machine for machining, and a 3-5 mm chamfer is provided at the welding position of each component. S200: The first reinforcing member 3 and the second reinforcing member 4 are respectively placed at predetermined positions on the upper surface of the base plate 1 and welded according to a predetermined welding method, wherein the first reinforcing member 3 and the second reinforcing member 4 are placed at the center position on the upper surface of the base plate 1. S300: The connector 2 is placed on the upper surface of the base plate 1 at a predetermined position between the first reinforcing member 3 and the second reinforcing member 4, and welded according to a predetermined welding method. The center surface of the connector 2 is coplanar with the center surface of the base plate 1. It should be noted that... Figure 4-7 The dashed line M shown is a side view of the center plane; By disassembling the mounting base into multiple independent components, firstly, this method simplifies manufacturing. Machining effectively ensures the precision of each component, meeting the accuracy requirements during thrust rod installation. Secondly, it overcomes the limitations of existing one-piece casting methods, which restrict the structure to a single mold. For special vehicle models or small-batch orders, there's no need to re-mold; simply changing the dimensional parameters of one or more components allows for quick adaptation to different brands and models of bridge assemblies and thrust rods. This reduces production costs and increases efficiency, solving the problems of high mold costs and long manufacturing cycles associated with existing one-piece casting methods. Finally, by limiting the assembly and welding processes, the deformation of each component can be effectively coordinated, resolving the issue of excessive positional errors in component assembly caused by heat deformation during welding. By prioritizing the placement of the first reinforcing member 3 and the second reinforcing member 4 and welding them, a rigid positioning support frame is established on the base plate 1. This design effectively absorbs and transfers welding heat and stress, thus limiting warping caused by thermal expansion and contraction during subsequent welding of the base plate 1. It also provides effective boundary constraints for the connector 2, preventing structural instability and excessive deformation after welding. This effectively controls the assembly position deviation of the connector 2, ensuring it meets the installation accuracy requirements of the V-type thrust rod of the dual rear axle assembly. If the connector 2 is placed first and then welded, the heat and stress generated during welding due to its large size will directly affect the base plate 1, causing overall warping or wavy deformation of the base plate 1. Furthermore, welding the connector 2 without reinforcement constraints will result in excessive assembly position deviation after welding. After the thrust rod is installed later, the thrust rod bushing will bear unnecessary additional bending moment and torsion, accelerating abnormal bushing wear, which in turn will cause abnormal tire wear, misalignment, or premature fatigue damage to the thrust rod and bushing.

[0024] Specifically, step S200 also includes: S210: Completely weld the first reinforcing member 3 to the base plate 1. It should be noted that complete welding means welding all the welds between the first reinforcing member 3 and the base plate 1. The welding current is set to 150A-170A. After welding, the first reinforcing member 3 is naturally cooled to room temperature. At this time, the first reinforcing member 3 and the base plate 1 are completely rigidly connected. S220: Two points are spot welded between the second reinforcing member 4 and the base plate 1. Preferably, the midpoint of the bottom edge of the second reinforcing member 4 on the side close to the first reinforcing member 3 and the midpoint of the bottom edge on the opposite side are spot welded. At this time, the second reinforcing member 4 and the base plate 1 are in a flexible connection that can be finely adjusted. Step S300 also includes: S310: Spot weld a point between the upper part of the first reinforcing member 3 and the connecting member 2. It should be noted that the upper part refers to the position near the top of the first reinforcing member 3. This setting is used to initially position the connecting member 2 to form a triangular support frame. S320: Weld the weld between the side of the connector 2 near the second reinforcing member 4 and the base plate 1. The welding current is set to 170A-190A. After welding, allow it to cool naturally to room temperature. S330: The second reinforcing member 4 is sequentially and completely welded to the connecting member 2 and the base plate member 1. The welding current is set to 150A-170A. After welding, the welding is naturally cooled to room temperature. S340: Weld the remaining weld between the connector 2 and the base plate 1. Set the welding current to 170A-190A. After welding, allow it to cool naturally to room temperature. S350: The first reinforcing member 3 is fully welded to the connecting member 2. The welding current is set to 190A-200A. After welding, the parts are allowed to cool naturally to room temperature. By designing the welding sequence and using an alternating, step-by-step welding method, the restraint state of each component is controlled. While completing the connection and fixation between the components, the welding stress can be gradually released and redistributed at different stages, avoiding excessive concentration of welding residual stress and effectively ensuring structural strength. It can also avoid the overlap of heat-affected zones of different welds, preventing abnormal grain growth and brittle phase aggregation at the junction, improving material properties, and further ensuring structural strength so that it can meet heavy load requirements. Secondly, by establishing an initial constraint frame of one rigid and one flexible reinforcing member, while ensuring stable support, the second reinforcing member 4 is allowed to have a certain slight offset capability, effectively suppressing the random deformation trend of the base plate 1. Furthermore, by welding the connecting member 2 to the side close to the second reinforcing member 4, the connection strength of the connecting member 2 is further improved. When the welding on this side is completed and cooled, the shrinkage stress will cause the area of ​​the base plate 1 where the connecting member 2 and the second reinforcing member 4 are located to generate stress towards the weld. The offset trend of the connecting side is further corrected by fully welding the second reinforcing member 4 to the connecting member 2 and the base plate member 1. The cooling shrinkage stress of the second reinforcing member 4 acts as a corrective force, which generates a force that pulls the area of ​​the base plate member 1 where the second reinforcing member 4 is located back. This can initially correct the initial offset generated in the above steps. Further, by welding the remaining weld between the connecting member 2 and the base plate member 1, the cooling shrinkage stress will further correct the initial offset to balance the offset trend generated in the above steps. Finally, by welding the first reinforcing member 3 and the connecting member 2, each component is fixed in the preset position. Based on the characteristics of welding heat deformation, this application coordinates the design of the welding sequence to transform the uncontrollable heat deformation process into a predictable and compensable process. The cooling shrinkage force of the step welding is used for dynamic offset correction, which can effectively offset and neutralize the residual stress generated in the welding process, control the overall deformation offset, reduce the assembly position deviation, and further ensure that it meets the installation accuracy requirements of the V-type thrust rod of the dual rear axle group.

[0025] Example 2 like Figure 2-7As shown, the difference from Embodiment 1 is that the base plate 1 has two identical limiting holes 11 symmetrically arranged relative to its center plane and penetrating the base plate 1; the connector 2 is an integral structure, including a first connecting part 21 and a second connecting part 22 symmetrically arranged relative to its center plane, and the lower surface of the connector 2 has two rectangular protrusions 23 symmetrically arranged relative to its center plane that are adapted to the limiting block. When the connector 2 is placed on the upper surface of the base plate 1, the rectangular protrusions 23 are inserted into the corresponding limiting holes 11, and the two are fitted with a gap. The height of the rectangular protrusions 23 is less than the depth of the limiting holes 11. Preferably, the gap between the rectangular protrusions 23 and the limiting holes 11 is 0.5 mm. Step S310 also includes: S311: Spot weld the midpoint of the bottom edge of the rectangular boss 23 to the limiting hole 11; Step S350 also includes: S351: Completely weld the rectangular boss 23 to the limiting hole 11, and fill the area of ​​the limiting hole 11 between the lower surface of the rectangular boss 23 and the lower surface of the base plate 1 through welding. The other steps and methods are the same as in Embodiment 1. With this setting, firstly, for vehicles with dual rear axles, the parallelism of the first connecting part 21 and the second connecting part 22 is crucial. This application can form a vertical constraint through the above setting, which, together with the first reinforcing member 3 and the second reinforcing member 4, constitutes a three-dimensional positioning system. While further reducing the lateral position deviation of the connecting member 2, it can also limit its vertical displacement, avoid vertical movement of the connecting member 2 during welding, and control the displacement deviation of the connecting member 2 within a very small range, effectively ensuring the assembly position accuracy. Furthermore, it can further limit the warping of the base plate 1 due to heat during welding, ensuring the fitting accuracy of the base plate 1 and the longitudinal beam of the frame; secondly, through the cooperation Setting the rectangular boss 23 and the limiting hole 11 with a clearance fit not only makes the assembly process smooth and reduces the assembly difficulty between the components, avoiding the assembly difficulties caused by interference fit, but also provides the necessary space margin because the welding process will produce uneven thermal expansion and cooling contraction. The thermal expansion is buffered by the clearance, allowing a small relative displacement between the rectangular boss 23 and the limiting hole 11, avoiding the problem of thermal stress not being released due to interference fit or zero clearance fit, which may lead to high residual stress or weld cracking. In addition, the reasonable clearance width can ensure good deposition and penetration of the welding material, forming a weld with a strength not lower than that of the base material.Finally, because the connecting piece 2 needs to withstand the alternating impact of dynamic loads on both axles and cope with the lateral movement of the two axles when the dual rear axle vehicle is in motion, the stress environment of the mounting base is quite complex, and the structural strength requirements of the mounting base are extremely high. By further coordinating the design of the welding sequence, firstly, spot welding can be used to further fix the vertical position and avoid displacement of the connecting piece 2 during subsequent welding. The area of ​​the limiting hole 11 between the lower surface of the rectangular boss 23 and the lower surface of the base plate 1 is completely filled by welding, thereby ensuring installation accuracy while enhancing connection strength. Secondly, it can enrich the vertical stress transmission path, allowing the rectangular boss 23 to release stress under lateral constraints. To reduce vertical stress and the cumulative amount of welding residual stress, the overall stress distribution becomes more uniform. Furthermore, after the weld is fully filled, during the cooling process, the pre-solidified weld metal on the periphery shrinks, generating continuous centripetal compressive stress on the still-high-temperature central area and the rectangular boss 23 itself. This forms a beneficial circumferential residual compressive stress field, which can significantly optimize the distribution of residual stress fields generated by the welding of other components, thereby reducing the stress concentration factor at the weld, reducing the probability of weld cracking, and ensuring overall rigidity. Thirdly, during use, the mounting base bears complex loads from the thrust rod, where a vertical load perpendicular to the base plate 1 acts on the connecting part... At time 2, the connector 2 has a tendency to be pulled out or pressed in relative to the base plate 1. If the rectangular boss 23 and the limiting hole 11 are not provided, the movement tendency can only be resisted by the metal weld. The weld is subjected to all shear and tensile stress, which can easily lead to fatigue cracking or even peeling. This application greatly enhances the local bending stiffness by providing the rectangular boss 23 inserted into the limiting hole 11. When a vertical load is applied, the relative torsional deformation between the connector 2 and the base plate 1 is suppressed, thereby reducing the harmful deformation and stress borne by the weld and making the weld in a more favorable stress state. Moreover, when subjected to vertical load, most of the vertical load is borne by the rectangular boss 23 inserted into the limiting hole 11. The shaped boss 23, the limiting hole 11, and the filler weld between them directly transfer the compressive stress to the base plate 1 body through contact stress, effectively reducing the load borne by the weld and further reducing the probability of weld fatigue cracking, enabling it to withstand greater loads and have better durability. Through the synergy of the above settings, this application ensures that the assembly position deviation of the mounting base after welding is ≤ ±0.1 mm, and under the condition of withstanding an 80 kN alternating cyclic load, the fatigue life is ≥ 2 million cycles. It should be noted that the position deviation is the maximum allowable variation of the actual position of the assembled component relative to the ideal position.

[0026] Specifically, the connector 2 is located in the area between the two rectangular bosses 23 and is not welded to the base plate 1. Firstly, this arrangement allows the area between the two rectangular bosses 23 to have a certain degree of free deformation, forming a structure with peripheral support and a free center. Because the connector 2 will exhibit bending deformation under the load of the thrust rod, if the area between the two rectangular bosses 23 were rigidly welded to the base plate 1, it would strongly constrain the bending tendency of the connector 2, leading to secondary bending stress and peeling stress in the area between the two rectangular bosses 23, which could easily induce fatigue cracks in the weld. By limiting the area between the two rectangular bosses 23 to not being welded, under the influence of bending deformation, the area between the two rectangular bosses 23 is allowed to undergo slight elastic bending, thereby reducing local peak stress and making the stress distribution more uniform. Furthermore, this arrangement allows thermal stress and shrinkage stress to be released through the slight deformation of this area during assembly and welding. The reduction in residual stress peak not only avoids weld microcracks and mid-section cracking of connector 2 caused by stress concentration, but also further prevents welding deformation and displacement of various components, ensuring structural integrity and assembly position accuracy. Secondly, this design optimizes the force transmission path, ensuring that the main load is transmitted through the rectangular bosses 23 on both sides, avoiding weld cracking caused by the dispersion of most loads to the weld due to chaotic force transmission paths. This design makes the weld stress more concentrated and uniform, effectively improving the weld fatigue life and making it suitable for long-term use under heavy-duty conditions of dual rear axles. Finally, this design makes the area between the two rectangular bosses 23 a thermal isolation area, avoiding abnormally coarse grains and reduced toughness and plasticity caused by the overlap of the heat-affected zones of various components, further ensuring structural strength and load-bearing performance.

[0027] Specifically, such as Figure 5-7As shown, the first connecting portion 21 and the second connecting portion 22 have symmetrically formed cuts 24. Above the cuts 24 is an upper mounting area 25, which has mounting holes 27 for connecting the thrust rod, and its first mounting surface 251, which abuts against the thrust rod, has a first preset slope. Below the cuts 24 is a lower mounting area 26, which has mounting holes 27 for connecting the thrust rod, and its second mounting surface 261, which abuts against the thrust rod, has a second preset slope. The bottom surface 2 of the cuts 24... 41. Both the upper side surface 242 and the lower side surface 243 are planar. One end of the upper side surface 242 is connected to the first mounting surface 251, and the other end is connected to the bottom surface 241 through an arc surface. One end of the lower side surface 243 is connected to the second mounting surface 261, and the other end is connected to the bottom surface 241 through an arc surface. The upper side surface 242 and the lower side surface 243 are arranged in parallel. The bottom surface 241 has a third preset slope, and the first preset slope, the second preset slope, and the third preset slope are all equal. During use, the thrust rod applies complex stress loads to the mounting base. The above configuration decomposes the input stress load into a tangential force parallel to the mounting surface and a pressure force perpendicular to the mounting surface. The tangential force is transmitted downwards in the form of shear stress, ultimately reaching the rectangular boss 23. Since the first mounting surface 251 and the second mounting surface 261 have the same preset slope, the directions of the two pressure forces generated by the decomposition are completely parallel and both perpendicular to the plane containing the bottom surface 241. The two pressure forces can be transmitted without loss via the upper side surface 242 and the lower side surface 243 to... On the plane where the bottom surface 241 is located, the force is then uniformly guided to the first reinforcing member 3 and the second reinforcing member 4 through the main body of the connecting member 2. This setting optimizes the force transmission path, efficiently sorts out and transmits complex stress loads. After the stress load is decomposed, it will not generate excessive peeling stress and out-of-plane bending stress, ensuring that the weld only bears a small stress amplitude, further avoiding weld cracking problems and effectively improving fatigue life. If the cutout 24 is a curved structure, it is very easy to generate complex multi-directional stress, which will cause the weld to crack or even fall off during use, thereby shortening the service life.

[0028] Specifically, such as Figure 5-8As shown, the second mounting surface 261 extends along a second preset slope and connects to the bottom side of the connector 2, and the outer side of the rectangular boss 23 is flush with the bottom side of the connector 2. This design first solves the problem that the load applied by the thrust rod, during transmission to the base plate 1, causes stress diffusion due to a sudden deflection of the force flow path, resulting in additional peeling stress on the weld. If the second mounting surface 261 does not extend to the bottom side of the base plate 1, or if its extension surface is misaligned with the outer side of the rectangular boss 23, the tangential force from the second mounting surface 261 must pass through a cantilever structure at the bottom of the connector 2 to be transmitted to the rectangular boss 23, causing a tensile bending moment in the weld at the root of the rectangular boss 23. With the above design, the tangential force can be directly transmitted along the slope to the turning point on the bottom side, allowing the force flow to directly enter the rectangular boss 23 without lateral deviation. 3. It eliminates the harmful bending moment caused by the lateral translation of force flow, further avoiding the problem of weld cracking or even falling off during use, and better ensuring that the mounting base described in this application can meet the heavy load requirements; Secondly, if the outer side of the rectangular boss 23 is protruding or recessed relative to the bottom side of the connector 2, a cross-sectional abrupt change zone will be formed between the rectangular boss 23 and the side of the connector 2 body. During welding assembly, this will cause heat accumulation, which is very easy to produce coarse brittle structure and accumulate welding residual stress. Through the above settings, this application allows heat to be conducted and dissipated smoothly during welding, avoiding local heat accumulation, thereby ensuring the local structural strength.

[0029] Specifically, such as Figure 6 As shown, the second mounting surface 261 has an included angle α with the center surface of the connector 2; There is an included angle β between the lower side surface 243 and the bottom surface 241 of the connector 2; The relationship between α and β satisfies 2°≤β-α≤5°, and the value of α ranges from 20° to 25°. This application ensures the basic angle for thrust rod installation by limiting the range of the included angle α. If α is less than 20°, the second mounting surface 261 and the first mounting surface 251 are too horizontal, resulting in an excessively large vertical component of the thrust rod load, increasing the tendency for the connector 2 to pull out relative to the base plate 1. If α is greater than 25°, the excessive horizontal component will cause the connector 2 to bear excessive in-plane shear, which is detrimental to structural stability. Although the force transmission path has been optimized through previous settings, the intersection and turning area between the second mounting surface 261 and the lower side 243 of the cutout 24 directly bears the complex alternating load applied by the thrust rod when the vehicle is under heavy load or turning conditions. If its local stiffness is insufficient, micro-elastic deformation will occur. Repeated micro-deformation will continuously pull on the root of the adjacent rectangular boss 23 and the upper part of the limiting hole 11. The weld seam is prone to fatigue cracking. By further optimizing the relationship between the included angles α and β, the mechanical properties of the intersection and transition area are improved while ensuring the stability of the thrust rod installation. This effectively enhances the local stiffness of the area and improves the overall fatigue life and reliability of the mounting base under heavy-load alternating conditions. This avoids the problem of local stress concentration in the area and solves the problem of thermal expansion compressing the lower mounting area 26 when welding the rectangular boss 23, causing unfavorable micro-closure deformation in the area and affecting the final thrust rod installation angle. If β-α is less than 2°, the transition area is too gentle. Although the stress concentration coefficient is reduced, the moment of inertia of the section in this area is small and the local structural strength is weak. It cannot effectively constrain the micro-deformation when bearing complex alternating loads, thus increasing the risk of weld cracking.

[0030] Specifically, such as Figure 6 , 7 As shown, the relationship between the distance L between the two rectangular bosses 23, the length S of the rectangular bosses 23, and the angle α between the second mounting surface 261 and the center plane of the connector 2 satisfies: In the formula, This is a correction factor, with a value ranging from 0.95 to 1.0; The standard included angle is 90°. This invention achieves this through the synergy of three parameters. First, as the length S of the rectangular boss 23 increases, the distance L between the two rectangular bosses 23 also increases. This is because the rectangular bosses 23 provide vertical rigidity positioning and optimize force flow transmission. The two rectangular bosses 23 are symmetrically distributed on both sides of the center plane of the connector 2, and their spacing L directly determines the load distribution range on the base plate 1 and the torsional stiffness of the bottom of the connector 2. When the length S increases, the longitudinal stress area of ​​a single rectangular boss 23 increases synchronously, thereby improving the vertical bearing capacity and the shear resistance of the root weld. If the spacing L remains unchanged or decreases, several problems will arise. First, the stress area of ​​the two rectangular bosses 23 on the base plate 1 will be excessively concentrated, causing a stress superposition zone to form in the area of ​​the base plate 1 between the two limiting holes 11, which can easily lead to the base plate 1 denting or cracking. Increasing the spacing L synchronously can evenly distribute the stress area of ​​the two rectangular bosses 23 on the base plate 1, effectively reducing the stress peak and ensuring the structural strength of the base plate 1. Second, if the spacing L remains unchanged or decreases, the torsional stiffness of the bottom of the connector 2 will be too low. The torsional force generated when the dual rear axle vehicle turns will cause the area of ​​the connector 2 between the two rectangular bosses 23 to have a torsional tendency, thus affecting the stability of the thrust rod's torque transmission. Increasing the spacing L synchronously can increase the torsional arm length of the bottom of the connector 2, effectively improving the torsional stiffness and ensuring the working of the thrust rod and the mounting base. Thirdly, when the length S of the rectangular boss 23 increases, the length of the corresponding limiting hole 11 also increases synchronously. The welding length between the rectangular boss 23 and the limiting hole 11 increases, and the welding heat input increases accordingly. It is easy to accumulate too much heat in a local area. If the spacing L does not increase, the spacing between the two limiting holes 11 will be too narrow, and the narrow area between the two rectangular bosses 23 will form a serious heat accumulation. After cooling, this area will generate extremely high residual tensile stress, which is very likely to cause weld cracking or warping deformation of the base plate 1. Increasing the spacing L synchronously can reduce the mutual influence of the welding heat-affected zone between the two limiting holes 11 and ensure the stability of welding quality. Secondly, when the length S of the rectangular boss 23 increases, by reducing the included angle α between the second mounting surface 261 and the center surface of the connector 2, it can ensure the overall force balance of the connector 2, optimize the decomposition of the stress load of the thrust rod, and make it accurately match the increased bearing capacity of the rectangular boss 23 due to the increase in length S, so as to ensure that its bearing capacity is fully utilized.

[0031] Specifically, such as Figure 7As shown, the intersection point of the extension line of the lower side surface 243 along its length direction and the center surface of the connector 2 is P0. The vertical distance from the intersection point P0 to the bottom surface 241 of the connector 2 is X1. The relationship between X1 and the height X2 of the connector 2 satisfies: X2 = (7.5-9)X1. First, while ensuring optimized force transmission path and extended weld fatigue life, this design limits the height of the lower mounting area 26 to a certain level. This ensures sufficient rigidity to better support the upper mounting area 25, preventing elastic bending deformation of the upper mounting area 25 under braking or impact loads. This avoids unexpected relative movement between the thrust rod and the mounting surface, accelerating wear and causing vibration and noise. Second, this design maintains a safe thermal buffer distance between the lower side 243 of the cutout 24 and the bottom surface 241 of the connector 2. This solves the problem of excessive heat concentration in the thin-walled area at the lower part of the cutout 24, exacerbating deformation and affecting the final dimensions. If X2 > 9X1, with a fixed tilt angle of the lower side 243, the lower side 243 is too close to the bottom surface 241 of the connector 2. This can lead to insufficient rigidity in the lower mounting area 26 to support the upper mounting area 25. Furthermore, because the structure in this area is relatively thin, the temperature rises sharply during welding, resulting in intense thermal expansion and significant shrinkage deformation after cooling. This can easily affect the angular accuracy of the already machined first mounting surface 251 and second mounting surface 261. Finally, when the vehicle turns, the dual rear axles will experience reverse torsion, with the middle axle exhibiting internal torsion and the rear axle external torsion. This torsional force can easily cause deformation of the mounting base, leading to weld cracking and accelerated abnormal bushing wear. This design determines a reasonable torsional arm length, effectively improving the torsional stiffness of the mounting base to ≥5000 N·m / rad. If X2 < 7.5X1, the arm is too short, resulting in insufficient torsional stiffness of the mounting base. Under the continuous action of an 80 kN alternating cyclic load, this leads to excessive torsional deformation.

[0032] Specifically, such as Figure 4 , 7As shown, the relationship between the length S of the rectangular boss 23, the height H of the rectangular boss 23, and the depth G of the limiting hole 11 satisfies S:H:G=1:(0.16-0.2):(0.22-0.25). It should be clarified that the length S of the rectangular boss 23 ensures positioning accuracy and load-bearing capacity. This setting ensures that the rectangular boss 23 provides sufficient support area along its length. The height H ensures vertical load-bearing rigidity while preventing deformation due to excessive height. The depth G of the limiting hole 11 ensures sufficient welding space. If the height H of the rectangular boss 23 < 0.16S, the vertical rigidity of the rectangular boss 23 is insufficient, making it prone to plastic deformation under vertical alternating loads. Furthermore, heat is more easily transferred and accumulated on the base plate during welding. 1. On the upper surface, local overheating can occur, and the resulting shrinkage tensile stress after cooling can easily lead to weld cracks. If the height H of the rectangular boss 23 is greater than 0.2S, the center of gravity of the rectangular boss 23 will shift upward, and it will easily generate a bending moment around the root when under stress, which will cause weld cracking. If the depth G of the limiting hole 11 is less than 0.22S, because the limiting hole 11 is a through hole set on the base plate 1, it will not only cause the base plate 1 to be too thin and have insufficient structural strength, making the base plate 1 very susceptible to deformation under the action of welding heat or operational impact, but it will also cause the rectangular boss to crack. The insufficient welding space between platform 23 and limiting hole 11 prevents the welding material from fully filling the space, easily leading to incomplete fusion defects. Secondly, this design solves the problems of superimposed welding thermal deformation and unstable weld quality. Within this range, it can accommodate sufficient welding material to ensure adequate local structural strength, while avoiding uneven heat input due to excessive filling space, which can lead to local grain coarsening, excessive local thermal deformation, and excessive residual welding stress, resulting in microcracks in the weld. Finally, this design ensures stable vertical positioning. Qualitatively, at this ratio, the height of the rectangular boss 23 is moderate. It can be inserted into the limiting hole 11 to form an effective constraint, but it will not interfere with the hole wall during assembly due to excessive height. At the same time, the support in the length direction can prevent the rectangular boss 23 from tilting. If H < 0.16S, the depth of the rectangular boss 23 inserted into the limiting hole 11 is insufficient, and it is easy to wobble left and right during positioning, resulting in excessive deviation in the final assembly position. If H > 0.2S, the fit clearance between the rectangular boss 23 and the limiting hole 11 is prone to interference due to machining errors, increasing the difficulty of machining.

[0033] Comparative Example 1 The difference between this comparative example and Examples 1 and 2 is that the base plate 1, the connector 2, the first reinforcing member 3 and the second reinforcing member 4 are integral structures formed by casting, and the rectangular boss 23 and the limiting hole 11 are not provided. All other contents are the same as in Example 2.

[0034] Comparative Example 2 The difference from Embodiment 1 and Embodiment 2 is that the base plate 1, the connector 2, the first reinforcing member 3 and the second reinforcing member 4 are integral structures formed by casting, and the rectangular boss 23 and the limiting hole 11 are not provided. The symmetrical cuts 24 of the first connecting part 21 and the second connecting part 22 are arc-shaped structures with continuous curved surfaces. All other contents are the same as in Embodiment 2.

[0035] Comparative Example 3 The difference from Embodiment 1 and Embodiment 2 is that the symmetrical cuts 24 of the first connecting part 21 and the second connecting part 22 are arc-shaped structures with continuous curved surfaces. All other contents are the same as Embodiment 1 and Embodiment 2.

[0036] The mounting brackets obtained through the above embodiments and comparative examples were subjected to performance tests. The specific test results are shown in Table 1 below. The test methods involved in the testing process are as follows: Assembly position accuracy: tested using a coordinate measuring machine; Fatigue life: The test was conducted using an electro-hydraulic servo fatigue testing machine with an 80kN alternating cyclic load. Tensile strength: tested using an electro-hydraulic servo universal testing machine; The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0037] For those skilled in the art, various modifications and improvements can be made without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A method for preparing a V-shaped thrust rod mounting base for a welded double rear axle assembly, characterized in that, The preparation method includes the following steps: S100: The base plate, connector, first reinforcing member, and second reinforcing member are machined separately. S200: Place the first reinforcing member and the second reinforcing member at predetermined positions on the upper surface of the base plate and weld them according to a predetermined welding method; S300: Place the connector on the upper surface of the base plate and at a predetermined position between the first reinforcing member and the second reinforcing member, and weld it according to a predetermined welding method.

2. The method for preparing the V-shaped thrust rod mounting base according to claim 1, characterized in that, Step S200 also includes: S210: Completely weld the first reinforcing member to the base plate; S220: Spot weld two points between the second reinforcing member and the base plate member; Step S300 also includes: S310: Spot weld a point between the upper part of the first reinforcing member and the connecting member; S320: Weld the weld between the side of the connector near the second reinforcing member and the base plate member; S330: The second reinforcing member is sequentially and completely welded to the connecting member and the base plate member; S340: Weld the remaining weld between the connector and the base plate; S350: Weld the first reinforcing member to the connecting member completely.

3. The method for preparing the V-shaped thrust rod mounting base according to claim 2, characterized in that, The base plate has two identical limiting holes that penetrate the base plate, symmetrically arranged relative to its central surface. The connector is an integral structure, including a first connecting part and a second connecting part symmetrically arranged relative to its central surface. The lower surface of the connector is provided with two rectangular protrusions adapted to the limiting block, symmetrically arranged relative to its central surface. When the connector is placed on the upper surface of the base plate, the rectangular protrusions are inserted into the corresponding limiting holes, and the two are clearance-fitted. The height of the rectangular protrusions is less than the depth of the limiting holes. Step S310 also includes: S311: Spot weld the midpoint of the bottom edge of the rectangular boss to the limiting hole; Step S350 also includes: S351: The rectangular boss is fully welded to the limiting hole, and the limiting hole area between the lower surface of the rectangular boss and the lower surface of the base plate is completely filled by welding.

4. The method for preparing the V-shaped thrust rod mounting base according to claim 3, characterized in that, The connector is located in the area between the two rectangular bosses and is not welded to the base plate.

5. The method for preparing the V-shaped thrust rod mounting base according to claim 4, characterized in that, The first connecting part and the second connecting part have symmetrical cuts. Above the cuts is an upper mounting area. The upper mounting area has mounting holes for connecting the thrust rod, and the first mounting surface that abuts against the thrust rod has a first preset slope. Below the cut is the lower mounting area, which has mounting holes for connecting the thrust rod, and the second mounting surface that abuts against the thrust rod has a second preset slope; The bottom, upper, and lower sides of the cut are all flat. One end of the upper side is connected to the first mounting surface, and the other end is connected to the bottom surface through an arc. One end of the lower side is connected to the second mounting surface, and the other end is connected to the bottom surface through an arc. The upper and lower sides are arranged in parallel. The bottom surface has a third preset slope, and the first preset slope, the second preset slope, and the third preset slope are all equal.

6. The method for preparing the V-shaped thrust rod mounting base according to claim 5, characterized in that, The second mounting surface extends along a second preset slope and connects to the bottom side of the connector, and the outer side of the rectangular boss is flush with the bottom side of the connector.

7. The method for preparing the V-shaped thrust rod mounting base according to any one of claims 5-6, characterized in that, The second mounting surface and the center surface of the connector have an included angle α; The lower side surface and the bottom surface of the connector have an included angle β; The relationship between α and β satisfies 2°≤β-α≤5°, and the value of α ranges from 20° to 25°.

8. The method for preparing the V-shaped thrust rod mounting base according to claim 7, characterized in that, The relationship between the distance L between the two rectangular bosses, the length S of the rectangular bosses, and the angle α between the second mounting surface and the center plane of the connector satisfies: In the formula, This is a correction factor, with a value ranging from 0.95 to 1.0; The standard included angle is 90°.

9. The method for preparing the V-shaped thrust rod mounting base according to claim 8, characterized in that, The intersection point of the extension line of the lower side along its length direction and the center surface of the connector is P0. The vertical distance from the intersection point P0 to the bottom surface of the connector is X1. The relationship between X1 and the height X2 from the top surface to the bottom surface of the connector satisfies: X2 = (7.5-9)X1.

10. The method for preparing the V-shaped thrust rod mounting base according to claim 9, characterized in that, The relationship between the length S of the rectangular boss, the height H of the rectangular boss, and the depth G of the limiting hole satisfies S:H:G=1:(0.16-0.2):(0.22-0.25).

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