Rectangular Coil Spring Coating for Noise and Wear Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Coil springs in vehicle suspension devices face issues with damage and noise due to contact between coil portions, and existing coatings concentrate stress, affecting durability and performance.
Innovation Solution
A coil spring with a wire rod featuring a rectangular cross-sectional portion and an elastic coat made of cured resin with urethane bonds, applied continuously along the wire rod, including a round, varying, and rectangular cross-sectional portions to distribute stress and prevent peeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a coating portion made of thermoplastic resin is provided on coil portions with round cross section to mitigate striking sound, then noise is reduced, but stress concentrates on the coating portion causing durability issues
Solution Approach 1:
The patent applies an elastic coat specifically on the first and second planes of the rectangular cross-sectional portion where coil portions contact each other, rather than uniformly coating the entire wire rod. This localized application targets the specific contact zones to reduce striking sound while avoiding stress concentration on curved surfaces, thereby improving coating durability.
Solution Approach 2:
Instead of coating round cross-sections (conventional approach), the patent inverts the approach by using a rectangular cross-sectional portion with elastic coat applied on its flat planes. This inversion eliminates the stress concentration problem inherent in coating curved surfaces while achieving the same noise mitigation function.
2Adaptability or versatility
If a wire rod with small cross sectional portion (tapered or flat-tapered) is used to achieve nonlinear characteristics, then suspension performance is improved, but scratches lead to serious damage
Solution Approach 1:
The patent applies an elastic coat specifically on the first and second planes of the rectangular cross-sectional portion, providing localized protection where coil portions contact each other during compression. This protects the critical small cross-sectional area from scratches and damage while maintaining the nonlinear suspension characteristics.
Solution Approach 2:
The elastic coat serves as a protective cushion applied beforehand on the rectangular cross-sectional portion, preventing direct contact and potential scratching between coil portions before damage can occur. This prior protection ensures durability while maintaining the desired nonlinear performance.
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 effectively suppresses damage and noise by distributing stress evenly and securing the elastic coat firmly, enhancing durability and reducing wear, while maintaining nonlinear characteristics for improved load handling.
Implementation Method 1
an elastic coat provided on at least one of the first plane and the second plane... to distribute stress and prevent peeling
Implementation Method 2
an elastic coat provided on at least one of the first plane and the second plane... tear strength... shear stress... compressive stress
Implementation Method 3
an elastic coat made of a cured material of a resin having urethane bonds... firmly secured to the wire rod to suppress defects such as peeling off
Data Source
AI summary
A coil spring includes a wire rod and an elastic coat provided on the wire rod. The coil spring includes a coil section including a plurality of coil portions. The wire rod includes a round cross-sectional portion, a cross-section varying portion, and a rectangular cross-sectional portion along the longitudinal direction of the wire rod. The cross section of the rectangular cross-sectional portion is substantially square and has a first plane and a second plane. The first plane and the second plane oppose each other in the coil section. The elastic coat is provided on at least one of the first plane and the second plane. The elastic coat is continuous from the round cross-sectional portion to the cross-sectional variation portion and the rectangular cross-sectional portion.