Lightweight Steering Knuckle with Composite Overmolding
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Solution Overview
Problem
Current steering knuckles made of cast iron are heavy and do not effectively utilize lightweight materials for weight reduction while maintaining necessary strength and stiffness to withstand application forces.
Innovation Solution
A steering knuckle composed of a fiber-reinforced composite material with a long-fiber molding compound overmolded onto a sleeve element and brackets, featuring a recessed annular groove for mechanical locking and a surface texture to enhance strength and stiffness, and a design that distributes load to prevent stress concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If steering knuckles are made from cast iron, then strength and stiffness are sufficient to withstand application forces, but weight is excessive and fuel economy is reduced
Solution Approach 1:
The steering knuckle is manufactured as a composite part using long-fiber reinforced thermoplastic polymer material, combining the lightweight benefits of polymers with the strength of fiber reinforcement. This composite material approach enables weight reduction while maintaining the necessary mechanical properties to withstand application forces.
Solution Approach 2:
The patent implements local reinforcement by incorporating fiber mats in specific regions where strength is required, such as at the bearing connection interface and bracket areas. The fiber orientation and density are optimized locally to match the stress distribution, providing strength where needed while keeping other areas lightweight.
2Weight of moving object
If lightweight fiber-reinforced polymer material is used, then weight is reduced and fuel economy improves, but strength and stiffness may be insufficient to withstand application forces
Solution Approach 1:
The steering knuckle is manufactured as a composite part using long-fiber reinforced thermoplastic polymer material, combining the lightweight benefits of polymers with the strength of fiber reinforcement. This composite material approach enables weight reduction while maintaining the necessary mechanical properties to withstand application forces.
Solution Approach 2:
The patent implements local reinforcement by incorporating fiber mats in specific regions where strength is required, such as at the bearing connection interface and bracket areas. The fiber orientation and density are optimized locally to match the stress distribution, providing strength where needed while keeping other areas lightweight.
3Reliability
If the bearing connection interface is robustly joined to the composite body, then reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The bearing connection interface is designed with an integrated locking mechanism that is formed as part of the composite body during the molding process. The locking features, such as recesses or protrusions, are pre-formed in the mold, allowing the bearing sleeve to be securely locked in place without requiring additional assembly steps or complex joining operations.
Solution Approach 2:
The bearing connection interface is integrated directly into the composite body of the steering knuckle, combining the bearing mounting function with the structural body. This integration eliminates separate joining components and simplifies the overall structure while maintaining robust connection through the molded-in locking mechanism.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a lightweight, robust steering knuckle capable of withstanding wheel and suspension forces, ensuring secure connections and improved mechanical properties through the use of fiber-reinforced composite materials.
Implementation Method 1
the long-fiber molding compound flows into the recessed portion, for mechanically locking the sleeve element to the composite body in an axial direction
Implementation Method 2
long-fiber molding compounds have excellent mechanical properties, which provide the steering knuckle with the necessary strength and stiffness to withstand the application forces
Data Source
AI summary
A steering knuckle comprising a bearing connection interface (formed by a sleeve element) for connecting a wheel bearing to the steering knuckle and further connection interfaces (formed by a bracket for connection of a ball joint) for connecting the steering knuckle to an upper and lower vehicle suspension control arm. A sleeve element bore is adapted to one of receive a wheel bearing outer ring or serve as the outer ring. The sleeve element and the bracket are joined by a composite body comprising a fiber-reinforced material. The fiber-reinforced material comprises a long fiber molding compound is overmolded to a first (sleeve element) joining surface and to a second (bracket) joining surface. The first joining surface is a radially outer surface thereof. The long-fiber molding compound flows into a recessed portion of the first joining surface for mechanically locking the sleeve element to the composite body in an axial direction.