CTBA Bushing Hardness Zoning for NVH and Ride Handling
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Solution Overview
Problem
The existing coupled torsion beam axle (CTBA) bushings have difficulty optimally addressing the behavior characteristics of vehicles in upward/downward, forward/rearward, and leftward/rightward directions due to single hardness compounds, leading to suboptimal NVH, ride quality, and R&H performance.
Innovation Solution
The CTBA bushing incorporates a bushing rubber with first, second, and third compounds of varying hardness and directions, integrated to provide distinct elastic restoring forces in different vehicle directions, enhancing NVH and R&H performance by optimizing hardness distribution across these axes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If single hardness compound is used in bushing rubber, then manufacturing is simple, but it is difficult to optimally cope with behavior characteristics in upward/downward, forward/rearward, and leftward/rightward directions
Solution Approach 1:
The bushing rubber is divided into multiple regions with different hardness characteristics. Specifically, it includes a first region with first hardness, a second region with second hardness, and a third region with third hardness, where the hardness values differ to optimize performance in different directional behaviors (upward/downward, forward/rearward, leftward/rightward). This local differentiation allows each region to specifically address the behavioral characteristics in its corresponding direction.
Solution Approach 2:
The bushing rubber employs a composite structure combining multiple materials or material phases with different hardness properties within a single component. This composite approach enables the bushing to simultaneously exhibit different mechanical characteristics in different directions, resolving the contradiction between simplicity and adaptability by integrating multiple functions into one composite element.
2Reliability
If multiple compounds with different hardness are used in bushing rubber, then NVH and R&H performance are improved, but manufacturing complexity increases
Solution Approach 1:
The bushing rubber is segmented into distinct regions (first, second, and third regions) with different hardness characteristics. Each region is positioned to address specific directional behaviors, allowing optimized NVH and R&H performance while maintaining a unified component structure that can be manufactured as a single integrated piece rather than assembling multiple separate components.
Solution Approach 2:
The invention varies the physical parameter of hardness across different regions of the bushing rubber. By controlling the hardness parameter to create first, second, and third regions with different hardness values, the design achieves superior NVH and R&H performance while the variations are implemented within a single manufacturing process, avoiding the need for complex multi-step assembly operations.
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
This configuration optimally copes with vehicle behavior characteristics, improving noise, vibration, and harshness (NVH) and ride and handling (R&H) performance by providing tailored hardness and elastic restoring forces in each direction.
Implementation Method 1
a bushing rubber disposed in the through-hole and positioned between an outer peripheral surface of the inner pipe and an inner peripheral surface of the outer pipe, in which the bushing rubber includes: first compounds extending in a first direction, which is a diameter direction of the inner pipe, with the inner pipe interposed therebetween; and a second compounds integrated with the first compounds and extending in a second direction, which is perpendicular to the first direction
Implementation Method 2
the bushing rubber includes a compound having single hardness... there is a problem in that it is difficult to optimally cope with behavior characteristics
Data Source
AI summary
A coupled torsion beam axle (CTBA) bushing is press-fitted into a bushing bracket provided at a tip of a trailing arm at each of two opposite sides of a CTBA suspension system. In particular, the CTBA bushing includes: an outer pipe including a through-hole formed therein; an inner pipe positioned in the through-hole; and a bushing rubber disposed in the through-hole and positioned between an outer peripheral surface of the inner pipe and an inner peripheral surface of the outer pipe, in which the bushing rubber includes: first compounds extending in a first direction, which is a diameter direction of the inner pipe, with the inner pipe interposed therebetween; and a second compounds integrated with the first compounds and extending in a second direction, which is perpendicular to the first direction, with the inner pipe interposed therebetween.