Automotive leaf spring assembly

Abstract

This utility model discloses an automotive leaf spring assembly, which is composed of at least two leaf spring bodies stacked together. The leaves are connected and positioned by an integrated bushing extending through the thickness direction of the leaf springs. The leaf spring bodies are made of composite materials. The cross-section of each leaf spring body has at least one closed cavity extending along its length. At the end of the uppermost leaf spring body, an integrated connecting frame is embedded. The connecting frame includes an anchoring head located inside the cavity and a connecting neck extending out of the end face of the leaf spring body. The anchoring head is provided with an anchoring structure for mechanical interlocking with the composite material. The integrated bushing includes a bushing body, and the outer wall of the bushing body has a radially protruding limiting flange. The limiting flange is engaged between two adjacent leaf spring bodies to limit their lateral movement. The bushing body also has a lubricating medium reservoir. This automotive leaf spring assembly achieves lightweight design while maintaining reliable connection and low maintenance requirements.

Description

Technical Field

[0001] This utility model relates to the field of automotive parts processing technology, specifically to an automotive leaf spring assembly. Background Technology

[0002] Lightweighting is a key technological path to improving vehicle fuel economy, increasing load capacity, and enhancing handling performance. Against this backdrop, using fiber-reinforced composite materials to replace traditional steel in leaf spring manufacturing has become an important development direction in the industry. However, composite leaf springs face a series of severe challenges in engineering applications.

[0003] First, the reliable connection between composite materials and metal connectors is the biggest technical bottleneck. Traditional methods of bonding to the leaf spring end face with adhesive or bolts are prone to stress concentration under alternating loads, leading to interlayer delamination or connection failure of the composite material, which severely restricts the load-bearing capacity and service life of the leaf spring.

[0004] Secondly, in order to achieve sufficient stiffness and strength, solid composite leaf springs often still require a large cross-sectional size, and the advantages of lightweighting cannot be fully utilized; while simple hollow designs may face the risk of local buckling instability.

[0005] Furthermore, when using a multi-leaf spring structure to adjust stiffness, the problems of lateral movement and dry friction between the leaves are particularly prominent. Lateral movement affects the stability of the assembly, while friction leads to abnormal noise, wear, and performance degradation. Existing technologies typically rely on separate limiting blocks and external lubrication points, resulting in complex structures and inconvenient maintenance. Utility Model Content

[0006] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to provide an automotive leaf spring assembly that achieves lightweight design while maintaining reliable connections and low maintenance requirements.

[0007] To achieve the above objectives, this utility model is implemented through the following technical solution: an automotive leaf spring assembly, wherein the leaf spring assembly is formed by stacking at least two leaf spring bodies, and the leaves are connected and positioned by an integrated bushing that runs through the thickness direction of the leaf spring; the leaf spring bodies are made of composite materials; The leaf spring body has at least one closed cavity extending along its length in its cross-section; at the end of the uppermost leaf spring body, a connecting frame is integrally embedded, the connecting frame including an anchoring head located inside the cavity and a connecting neck extending out of the end face of the leaf spring body; the anchoring head is provided with an anchoring structure for mechanically interlocking with the composite material. The integrated bushing includes a bushing body, on the outer wall of which is provided a radially protruding limiting flange. The limiting flange is positioned between two adjacent leaf spring bodies to restrict their lateral movement. The bushing body also has a lubricating medium storage cavity.

[0008] Furthermore, the inner wall of the closed cavity is integrally formed with reinforcing ribs, which divide the cavity into multiple continuous chambers, and the anchoring head is embedded in and fills at least one of the chambers.

[0009] Furthermore, the anchoring structure is a through hole, blind hole, annular groove, or irregular protrusion opened on the anchoring head.

[0010] Furthermore, the connecting neck is provided with mounting holes for connecting to the axle or lug.

[0011] Furthermore, the leaf spring body is made of fiber-reinforced thermosetting or thermoplastic composite material.

[0012] Furthermore, the lubricating medium reservoir is an oil guide channel that penetrates the wall thickness of the bushing body.

[0013] The beneficial effects of this utility model are: The aforementioned automotive leaf springs have at least the following advantages: 1. This automotive leaf spring: By deeply embedding the anchoring head of the metal connecting frame inside the closed cavity of the leaf spring body and setting a mechanically interlocking anchoring structure, the traditional dangerous "end face connection" is transformed into a stable "internal structure connection". This allows the force to be smoothly and efficiently transferred from the metal connector to the composite material body through the maximized contact area and optimized path, completely avoiding the risks of end stress concentration and interlayer delamination, and ensuring the durability of the connection part under long-term harsh working conditions.

[0014] 2. The closed cavity structure inside the leaf spring body of this car removes the material with low stress near the neutral shaft, achieving a significant weight reduction while ensuring overall stiffness and strength, which helps to improve the vehicle's energy efficiency and load capacity.

[0015] 3. The limiting flange on the outer wall of this automotive leaf spring forms a physical barrier between adjacent leaf springs, effectively limiting lateral movement and improving the stiffness and stability of the entire leaf spring assembly. Simultaneously, the internal lubrication medium reservoir serves as a continuous lubrication source, providing lubrication to the contact surfaces between the leaf springs, significantly reducing the coefficient of friction, wear, and operating noise. This greatly extends the service life of the assembly and reduces maintenance needs and costs. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0017] Figure 1 A schematic diagram of an automotive leaf spring assembly provided in an embodiment of the present invention; Figure 2 for Figure 1 The cross-sectional view of the leaf spring body in the automotive leaf spring assembly shown; Figure 3 for Figure 1 A schematic diagram of an integrated bushing in an automotive leaf spring assembly is shown. Figure 4 for Figure 1 The diagram shows the connecting frame in the automotive leaf spring assembly. Figure label: 100. Leaf spring body; 110. Reinforcing rib; 200. Integrated bushing; 210. Bushing body; 220. Limiting flange; 230. Lubricating medium reservoir; 300. Connecting frame; 310. Anchoring head; 311. Anchoring structure; 320. Connecting neck; 321. Mounting hole. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention; therefore, the invention is not limited to the specific embodiments disclosed below.

[0019] Please see Figures 1 to 4 This utility model provides an automotive leaf spring assembly, which is composed of at least two leaf spring bodies 100 stacked together. The leaves are connected and positioned by an integrated bushing 200 that runs through the thickness direction of the leaf spring. The leaf spring bodies 100 are made of composite materials.

[0020] Specifically, the leaf spring body 100 has at least one closed cavity extending along its length within its cross-section. That is, the cavity is not localized but rather serves as part of the leaf spring's main load-bearing structure, extending through most of its working length. This cavity allows for the significant removal of material that does not bear the main stress without substantially sacrificing overall stiffness and strength, thus achieving extreme lightweighting. This is similar to the concept of an "I-beam" in construction, concentrating material on the upper and lower surfaces where the stress is greatest, while hollowing out the middle.

[0021] At the end of the leaf spring body 100, an integral connecting frame 300 is embedded. The connecting frame 300 includes an anchoring head 310 and a connecting neck 320. Specifically, the anchoring head 310 is located inside a closed cavity, enabling smooth and efficient transfer of load from the metal component to the composite material body structure. The connecting neck 320 extends from the end face of the leaf spring body 100, serving as a standard interface with the vehicle chassis (axle or hanger). When the leaf spring is connected to the axle or hanger via the connecting neck 320 and bears a load, the force is smoothly transferred to the composite material leaf spring body 100 through the anchoring head 310, which is deeply embedded inside the cavity, with a maximized contact area and path, thereby preventing the force from concentrating on the end face.

[0022] A dedicated anchoring structure 311 is provided on the anchoring head 310. The principle of the anchoring structure 311 is "mechanical interlocking". The anchoring structure 311 no longer relies on the chemical bonding force of adhesives or simple surface friction, but through geometric features processed on the metal parts, the composite resin matrix flowing during the manufacturing process can be embedded and solidified inside these features, forming a mechanical connection like a "key and lock".

[0023] The integrated bushing 200 includes a bushing body 210. The bushing body 210 passes through bolt holes in each leaf spring and has a radially protruding limiting flange 220 on its outer wall. When the bushing is installed in place, the limiting flange 220 is precisely engaged between adjacent leaf spring bodies 100. Its core function is to provide a physical barrier, effectively limiting the lateral relative movement of the stacked leaves in the direction perpendicular to the leaf spring plane. Furthermore, the bushing body 210 also contains a lubricating medium reservoir 230. This reservoir acts as a source of slowly released lubricant, continuously providing lubrication to the contact surfaces between the leaf springs.

[0024] This structure, with its closed cavity, removes inefficient materials near the neutral axis, achieving a lighter weight than a solid structure and directly improving vehicle energy efficiency and load capacity. Furthermore, the anchoring head 310 of the connecting frame 300 is deeply embedded within the main load-bearing cavity, transforming the traditional "end-face connection" into an "internal structural connection," significantly improving stress distribution and effectively avoiding the risks of interlaminar delamination and end tearing of the composite material. Simultaneously, the mechanically interlocked anchoring structure 311 offers significantly higher connection strength than traditional methods, ensuring durability under long-term alternating loads.

[0025] Furthermore, the limiting flange 220 of the integrated bushing 200 effectively prevents lateral movement between the leaf springs, improving the overall stability of the assembly; while its built-in lubrication medium reservoir 230 significantly reduces inter-leaf friction, wear, and operating noise, greatly extending service life. These three elements work together to create a high-performance, highly reliable leaf spring system.

[0026] In this embodiment, reinforcing ribs 110 are integrally formed on the inner wall of the closed cavity. "Integral forming" here means that during the manufacturing process of the composite leaf spring (such as molding, pultrusion, or winding), these reinforcing ribs 110 are formed simultaneously with the cavity wall and the outer wall of the leaf spring as a whole. The function of the reinforcing ribs 110 is to act as an internal "skeleton," dividing the large cavity into several smaller load-bearing units.

[0027] The stiffener 110 effectively prevents buckling, collapse, or deformation of the cavity wall under pressure, ensuring the stability of the hollow structure while maintaining its lightweight design. Simultaneously, the stiffener 110 distributes and disperses the load more evenly across the entire leaf spring cross-section, reducing localized stress concentration and thus improving overall fatigue resistance and load-bearing capacity.

[0028] In this embodiment, the reinforcing rib 110 divides the cavity into multiple continuous, independent chambers. Therefore, when the anchoring head 310 connecting the frame 300 is inserted, it is not simply located within a large cavity, but is designed to insert into and fill at least one complete chamber. This means that the shape and size of the anchoring head 310 are matched to a specific chamber.

[0029] The metal anchor head 310 forms a "surface contact" or even a "body contact" with the composite material cavity, making the connection exceptionally strong and virtually eliminating any possibility of loosening. The load is directly and efficiently transferred to the reinforcing ribs 110 that separate the cavity through the metal head filled in the cavity, and then from the reinforcing ribs 110 to the entire leaf spring structure, with a clear path and extremely high efficiency.

[0030] In this embodiment, the anchoring structure 311 can be: Through holes / blind holes: Resin flows into the hole and, after curing, forms a "resin pin" that locks the metal part from the inside.

[0031] Annular groove: Resin is filled into the groove to form a ring-shaped "locking ring" effect, preventing axial pull-out.

[0032] Irregular protrusions (such as barbs, knurling, and asymmetrical blocks): These structures prevent the resin from detaching from the metal surface after curing, providing multi-directional locking capability, especially when subjected to vibration and impact loads.

[0033] Structures such as through holes / blind holes, annular grooves, and irregular protrusions can significantly increase the effective bonding area between composite materials and metals, further strengthening the connection strength.

[0034] In this embodiment, a mounting hole 321 is provided on the connecting neck 320. The mounting hole 321 is used to connect the frame 300 to the vehicle chassis (axle or hanger). Since this part is a pure metal structure, a mature mechanical connection method can be used, such as using high-strength bolts to pass through the mounting hole 321 for fastening.

[0035] Using this type of automotive leaf spring assembly eliminates the need to modify the axle or hanger design, allowing it to directly replace traditional steel leaf springs. This leaf spring utilizes a metal-to-metal connection, resolving the issues of insufficient thread strength and poor wear resistance in composite materials, thus ensuring the reliability and durability of all vehicle connection points.

[0036] In practical implementation, the leaf spring body 100 can be made of fiber-reinforced thermosetting (such as epoxy resin, polyurethane) or thermoplastic (such as nylon, polypropylene) composite materials. Thermosetting composite materials generally have higher stiffness and heat resistance, and the process is mature, making them the preferred choice at present. Thermoplastic composite materials, on the other hand, have the potential advantages of good toughness, short production cycle, and recyclability.

[0037] In this embodiment, the lubricating medium reservoir 230 is an oil guide channel that penetrates the wall thickness of the bushing body 210. This channel can guide the grease pre-filled in the oil reservoir at one end of the bushing, or the lubricating oil added through regular maintenance, to the contact surface between the outer wall of the bushing and the leaf spring hole wall, as well as the most critical contact surface between the leaf springs adjacent to the limiting flange 220.

[0038] This type of automotive leaf spring assembly ensures that the contact surfaces between the leaf springs are always well lubricated, significantly reducing the coefficient of friction and minimizing wear and abnormal noise caused by dry friction.

[0039] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. An automotive leaf spring assembly, characterized in that: The leaf spring assembly is composed of at least two leaf spring bodies stacked together, with the leaves connected and positioned by an integrated bushing that runs through the thickness direction of the leaf spring; the leaf spring bodies are made of composite materials. The leaf spring body has at least one closed cavity extending along its length in its cross-section; at the end of the uppermost leaf spring body, a connecting frame is integrally embedded, the connecting frame including an anchoring head located inside the cavity and a connecting neck extending out of the end face of the leaf spring body; the anchoring head is provided with an anchoring structure for mechanically interlocking with the composite material. The integrated bushing includes a bushing body, on the outer wall of which is provided a radially protruding limiting flange. The limiting flange is positioned between two adjacent leaf spring bodies to restrict their lateral movement. The bushing body also has a lubricating medium storage cavity.

2. The automotive leaf spring assembly according to claim 1, characterized in that: The inner wall of the closed cavity is integrally formed with reinforcing ribs, which divide the cavity into multiple continuous chambers. The anchoring head is embedded in and fills at least one of the chambers.

3. The automotive leaf spring assembly according to claim 1, characterized in that: The anchoring structure is a through hole, blind hole, annular groove, or irregular protrusion opened on the anchoring head.

4. The automotive leaf spring assembly according to claim 1, characterized in that: The connecting neck is provided with mounting holes for connecting to the axle or lifting lug.

5. The automotive leaf spring assembly according to claim 1, characterized in that: The leaf spring body is made of fiber-reinforced thermosetting or thermoplastic composite material.

6. The automotive leaf spring assembly according to claim 1, characterized in that: The lubricating medium reservoir is an oil guide channel that penetrates the wall thickness of the bushing body.

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