A front subframe stabilizer bar mounting point high-strength thin-walled load-bearing structure

Abstract

The present application relates to the technical field of automobile chassis structure, and particularly relates to a high-strength thin-walled bearing structure of a front subframe stabilizer bar mounting point, which comprises a stabilizer bar reinforcing plate, a stabilizer bar support plate arranged below the stabilizer bar reinforcing plate, a stabilizer bar mounting threaded sleeve one arranged at one end of the stabilizer bar reinforcing plate, and a stabilizer bar mounting threaded sleeve two arranged at the other end of the stabilizer bar reinforcing plate. The present application obviously improves the local mounting stiffness through the stabilizer bar reinforcing plate and the stabilizer bar support plate, is more suitable for external high-load environments and relatively complex alternating load working conditions, can effectively and uniformly disperse the external incoming stress, reduces the product fatigue cracking risk, improves the control stability and driving safety, and improves the vehicle comfort. The relative precision between mounting holes is better ensured through the positioning of the end step structure of the mounting threaded sleeve, which is beneficial to the product assembly and assembly, the connection between parts is achieved through MAG welding, the welding process is simple, the welding workability is good, the product weight meets the design target under the condition of meeting the high-load working environment, the cost is controllable, and the product structure optimization design is reflected.

Description

Technical Field

[0001] This invention relates to the field of automotive chassis structure technology, specifically a high-strength, thin-walled load-bearing structure for the front subframe stabilizer bar mounting point. Background Technology

[0002] The front subframe is a key structural component of the automotive chassis system, used to support the powertrain, suspension, and steering systems, and to transfer loads to the vehicle body. Its structural stiffness and vibration characteristics directly affect the vehicle's handling stability and fatigue life. With the increasing demands for lightweight vehicles and higher NVH performance standards, the design of the mounting structures for various systems on the front subframe faces the challenge of balancing stiffness, strength, and weight. The stabilizer bar, a crucial elastic element fixed to the front subframe, plays a vital role in reducing body roll during cornering, thereby improving handling stability and driving safety. Traditional mounting connections between the stabilizer bar and the subframe are often limited to a single sheet metal structure or simple reinforcements, resulting in insufficient local stiffness. In actual use, the mounting points are subjected to alternating loads and impacts over long periods, making them highly susceptible to serious failures such as localized stress concentration, fatigue cracking, bolt loosening, and even chassis system fracture. Therefore, the stability and reliability of the mounting structure play a crucial role in its functional performance. Summary of the Invention

[0003] To improve the structural stiffness of the mounting point, optimize the load transfer path, evenly distribute the stress transmitted by the external load, reduce the strength of each component, avoid failures such as cracking and fracture caused by stress concentration, and achieve lightweight structural design, this invention proposes a high-strength thin-walled load-bearing structure for the mounting point of the front subframe stabilizer bar.

[0004] A high-strength, thin-walled load-bearing structure for the front subframe stabilizer bar mounting point includes a stabilizer bar reinforcing plate, a stabilizer bar support plate disposed below the stabilizer bar reinforcing plate, and stabilizer bar mounting threaded sleeve one and stabilizer bar mounting threaded sleeve two disposed at both ends of the stabilizer bar reinforcing plate. The stabilizer bar reinforcement plate, stabilizer bar support plate, stabilizer bar mounting threaded sleeve one, and stabilizer bar mounting threaded sleeve two are welded together by MAG welding.

[0005] Furthermore, both ends of the stabilizer bar reinforcement plate are provided with flanged reinforcing ribs to improve the strength of the mounting surface of the stabilizer bar reinforcement plate.

[0006] Furthermore, the stabilizer bar mounting threaded sleeve one and stabilizer bar mounting threaded sleeve two adopt an internal threading structure and are made of 40Cr alloy steel.

[0007] Furthermore, the stabilizer bar mounting threaded sleeve one and stabilizer bar mounting threaded sleeve two are of the same structure, and both are designed with a stepped positioning structure at the upper end.

[0008] The beneficial effects of this invention are as follows: The stabilizer bar reinforcement plate and stabilizer bar support plate significantly improve local installation stiffness, making it more adaptable to external high-load environments and complex alternating load conditions. It effectively and evenly disperses externally transmitted stress, reduces the risk of product fatigue cracking, improves handling stability and driving safety, and enhances overall vehicle comfort. The stepped structure at the end of the threaded sleeve ensures better positioning and relative accuracy between mounting holes, facilitating final assembly. The welding process is simple and has good weldability. Under high-load operating conditions, the product weight meets design targets, costs are controllable, and the product structure is optimally designed. Attached Figure Description

[0009] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0010] Figure 1 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the welding process of the present invention. Figure 1 ; Figure 3 This is a schematic diagram of the welding structure of the present invention. Figure 2 ; Figure 4 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 2 ; Figure 5 This is a schematic diagram of the stabilizer bar mounting threaded sleeve structure of the present invention; Figure 6 This is a schematic diagram of the exploded structure of the present invention; Figure 7 This is a schematic diagram of the welding edge of the present invention; Figure 8 This is a schematic diagram of the installation location structure of the present invention; Figure 9 This is an enlarged structural diagram of the installation position of the present invention; Figure 10 This is a schematic diagram of the partial weld strength of the upper plate of the front subframe under the right-turn condition of the present invention; Figure 11 This is a schematic diagram of the local weld strength of the lower plate of the front subframe under right-turn conditions according to the present invention; Figure 12 This is a schematic diagram of the partial weld strength of the upper plate of the front subframe under the left-turning condition of the present invention; Figure 13 This is a schematic diagram of the local weld strength of the lower plate of the front subframe under the left-turning condition of the present invention; Figure 14 This is a schematic diagram of the local weld strength of the front subframe lower plate after optimization under the right-turn condition according to the present invention; Figure 15 This is a schematic diagram of the local weld strength of the front subframe lower plate after optimization under the left-turn condition according to the present invention; Reference numerals: 1. Stabilizer bar reinforcement plate; 11. Flanged reinforcement rib; 12. Weld plug hole; 13. Welded edge; 2. Stabilizer bar support plate; 3. Stabilizer bar mounting threaded sleeve one; 4. Stabilizer bar mounting threaded sleeve two; 5. Step positioning structure; 6. Front subframe upper plate; 7. Front subframe lower plate. Detailed Implementation

[0011] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below.

[0012] like Figures 1 to 15 As shown, a high-strength thin-walled load-bearing structure for the front subframe stabilizer bar mounting point includes a stabilizer bar reinforcing plate 1, a stabilizer bar support plate 2 located below the stabilizer bar reinforcing plate 1, a stabilizer bar mounting threaded sleeve 3 located at both ends of the stabilizer bar reinforcing plate 1, and a stabilizer bar mounting threaded sleeve 4. The mating surfaces of the stabilizer bar reinforcing plate 1 and the upper plate 6 of the front subframe are welded to the inside by two lap welds and two plug welds. The mating surfaces of the stabilizer bar reinforcing plate 1 and the lower plate 7 of the front subframe are welded from the bottom outside by one plug weld and two sleeve circumferential full welds, so as to effectively distribute and transmit the external load force among the connecting parts.

[0013] The present invention significantly improves the local installation stiffness through the stabilizer bar reinforcement plate 1 and stabilizer bar support plate 2, making it more adaptable to external high load environments and complex alternating load conditions. It can effectively and evenly distribute externally transmitted stress, reduce the risk of product fatigue cracking, improve handling stability and driving safety, and enhance the overall vehicle comfort.

[0014] like Figure 1 , Figure 2 and Figure 3 As shown, the stabilizer bar reinforcement plate 1, stabilizer bar support plate 2, stabilizer bar mounting threaded sleeve 1 3, and stabilizer bar mounting threaded sleeve 2 4 are welded together by MAG welding, with a total of 7 welds and a total weld length of 164mm. The "stabilizer bar support plate 2" serves as the central connecting component, connecting the "stabilizer bar reinforcement plate 1" and the "stabilizer bar mounting threaded sleeve 1 3" and "stabilizer bar mounting threaded sleeve 2 4" together through 4 welds. This effectively transfers and disperses the unstable compressive and tensile stresses transmitted from the mounting surface between the sheet metal parts and to the lower plate of the subframe. The parts are welded together by MAG welding to form a "bridge" structure, ensuring stable connection.

[0015] The MAG welding described uses carbon dioxide shielded welding, which is simple and has good weldability. Under high-load operating conditions, the product weight meets design targets, costs are controllable, and it reflects the optimal design of the product structure. Figure 2 , Figure 3 As shown in the figure, the reference numerals a, b, c, d, e, f, and g represent seven welds. The weld length of reference numeral a is 30 mm, the weld lengths of reference numerals b, d, f, and g are 15 mm, and the weld length of reference numeral c is 50 mm.

[0016] The stabilizer bar reinforcement plate 1 and the stabilizer bar support plate 2 are both made of QStE420TM material with a thickness of 3.0mm.

[0017] like Figure 4 As shown, both ends of the stabilizer bar reinforcement plate 1 are provided with flanged reinforcing ribs 11 to improve the strength of the mounting surface of the stabilizer bar reinforcement plate 1, and matching welding edges 13 are reserved on both sides, with an effective welding length of 43mm.

[0018] Specifically, the outline of the flanged reinforcing rib 11 is set to an arc shape, which further stabilizes the strength of the mounting surface of the stabilizing rod reinforcing plate 1 and has a better support effect than the straight edge support.

[0019] like Figure 3 and Figure 4 As shown, the mounting surface of the stabilizer bar reinforcing plate 1 is provided with plug welding holes 12. The plug welding holes 12 are 50mm long and 4mm wide, ensuring that the welding penetration depth of the welds on both sides of the plug welding meets the definition. The four welds here play a key connection role and are indispensable. In order to ensure that the reinforcing member is fully and tightly connected to the body, the internal stress can be effectively transferred.

[0020] like Figure 5 As shown, the stabilizer bar mounting threaded sleeve 1 3 and stabilizer bar mounting threaded sleeve 2 4 adopt the internal tapping thread structure of the pipe fittings. The material is 40Cr alloy steel. After heat treatment, the material has good comprehensive mechanical properties, ensuring thread strength and load-bearing capacity. The upper end is designed as a stepped positioning structure.

[0021] like Figure 6 As shown, the stabilizer bar mounting threaded sleeve 1 3 and stabilizer bar mounting threaded sleeve 2 4 have the same structure. The upper end of both is designed as a stepped positioning structure 5. When welding with the "stabilizer bar reinforcing plate 1", the step is completely inserted into the stamping hole, which can effectively avoid deformation caused by welding heat. The welding positioning accuracy is high, and the relative position accuracy at the stamping part level can be achieved after welding, which is beneficial to the final assembly of the product.

[0022] Performance Analysis: The single-unit performance analysis of the front subframe assembly mainly examines the stress distribution under 16 working conditions. The goal is to ensure that the stress value of the component body is lower than the material yield strength and the stress value of the weld is lower than the design definition value. The 16 working conditions include 8 normal working conditions, 4 extreme working conditions, and 4 abuse working conditions.

[0023] To verify the effectiveness of this solution, a CAE finite element model was established and analyzed using actual project data. According to the analysis results, the weld strength at the stabilizer bar installation point does not meet the design requirements, mainly during left and right turns.

[0024] Depend on Figures 10 to 13 It can be seen that, in the initial design, the weld strength at the stabilizer bar mounting point on the upper plate of the subframe is 575.94 MPa and that of the lower plate is 420.15 MPa, both exceeding the design requirement of 320 MPa. Similarly, in the left turn condition, the upper plate has the highest strength of 554.58 MPa and that of the lower plate is 433.88 MPa, both failing to meet the design performance requirements.

[0025] Analysis results show that, due to structural optimization, the upper front subframe plate 6 has no weld strength exceeding the standard, and all welds on the lower front subframe plate 7 meet the design requirement of less than 320MPa. See details... Figure 14 , Figure 15 .

[0026] Based on the original structural design, an internal reinforcing structure is added. The overall frame is formed by connecting sheet metal and threaded sleeves through carbon dioxide shielded welding. This frame is then connected to the external sheet metal. The stress transmitted from the external load is evenly distributed throughout the overall frame structure. Under high loads, multiple force transmission paths are used to ensure that the load-bearing strength of both the sheet metal body and the weld is lower than the target value. This avoids the risk of fatigue cracking due to localized stress concentration in the product.

[0027] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely prisms of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A high-strength, thin-walled load-bearing structure for the front subframe stabilizer bar mounting point, characterized in that: Includes stabilizer bar reinforcement plate (1), stabilizer bar support plate (2) set below stabilizer bar reinforcement plate (1), stabilizer bar mounting threaded sleeve one (3) set at both ends of stabilizer bar reinforcement plate (1), and stabilizer bar mounting threaded sleeve two (4); The stabilizer bar reinforcement plate (1), stabilizer bar support plate (2), stabilizer bar mounting threaded sleeve one (3), and stabilizer bar mounting threaded sleeve two (4) are welded together by MAG welding.

2. The high-strength thin-walled load-bearing structure for the front subframe stabilizer bar mounting point according to claim 1, characterized in that: The MAG welding is performed using carbon dioxide shielded welding.

3. The high-strength thin-walled load-bearing structure for the front subframe stabilizer bar mounting point according to claim 1, characterized in that: The stabilizer bar reinforcement plate (1) and stabilizer bar support plate (2) are both made of QStE420TM material with a thickness of 3.0mm.

4. The high-strength thin-walled load-bearing structure for the front subframe stabilizer bar mounting point according to claim 1, characterized in that: Both ends of the stabilizer bar reinforcement plate (1) are provided with flanged reinforcing ribs (11) to improve the strength of the mounting surface of the stabilizer bar reinforcement plate (1).

5. The high-strength thin-walled load-bearing structure for the front subframe stabilizer bar mounting point according to claim 4, characterized in that: The outline of the flanged reinforcing rib (11) is set as an arc.

6. The high-strength thin-walled load-bearing structure for the front subframe stabilizer bar mounting point according to claim 1, characterized in that: The mounting surface of the stabilizer bar reinforcement plate (1) is provided with plug welding holes (12).

7. The high-strength thin-walled load-bearing structure for the front subframe stabilizer bar mounting point according to claim 1, characterized in that: The stabilizer bar mounting threaded sleeve one (3) and stabilizer bar mounting threaded sleeve two (4) adopt the internal tapping thread structure of the pipe fittings and the material is 40Cr alloy steel.

8. The high-strength thin-walled load-bearing structure for the front subframe stabilizer bar mounting point according to claim 1, characterized in that: The stabilizer bar mounting threaded sleeve one (3) and stabilizer bar mounting threaded sleeve two (4) are of the same structure, and both are designed with a stepped positioning structure (5) at the top.

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