Resin Sliding Layer Composition for Stable Shock Absorber Friction
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Solution Overview
Problem
Conventional sliding members for shock absorbers in automobiles fail to maintain a small difference between static and dynamic frictional forces as they wear, affecting riding comfort and driving stability.
Innovation Solution
A sliding member with a back metal layer and a sliding layer containing a resin material, porous metal, and a solid lubricant, where the sliding layer has a specific Martens hardness and creep deformation ratio, ensuring a consistent frictional force difference regardless of wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the composition of the sliding layer is adjusted to reduce the change rate of static and dynamic frictional forces, then the frictional force stability is improved, but the effect is limited to 20% reduction and further improvement is difficult
Solution Approach 1:
The patent changes the physical and chemical parameters of the sliding layer by controlling Martens hardness to 25-45 N/mm² and creep deformation ratio to 10-30%, which fundamentally alters the frictional force characteristics and enables reduction of the change rate between static and dynamic frictional forces to 15% or less
Solution Approach 2:
The patent uses a composite sliding layer containing resin material, porous metal, and solid lubricant, where each component contributes specific properties: the resin provides low friction, the porous metal provides structural support and lubricant retention, and the solid lubricant reduces wear, achieving synergistic effect that improves frictional force stability beyond what single materials can achieve
2Reliability
If an uneven surface is formed on the sliding surface to control the relationship between static and dynamic frictional forces, then the frictional force control is improved, but the shape of unevenness is lost as the sliding surface wears
Solution Approach 1:
Instead of relying on surface geometry (unevenness) that degrades with wear, the patent changes the material parameters by controlling Martens hardness and creep deformation ratio, which are intrinsic properties that remain stable throughout the service life, ensuring consistent frictional force control from new to worn condition
Solution Approach 2:
The patent replaces the durable but wear-sensitive uneven surface structure with a material composition approach using resin, porous metal, and solid lubricant that maintains its functional properties throughout the entire service life, effectively making the frictional force control mechanism wear-resistant rather than replaceable
3Ease of operation
If the difference between static frictional force and dynamic frictional force is reduced to improve riding comfort, then the riding comfort is improved, but driving stability may be affected
Solution Approach 1:
The patent precisely controls Martens hardness (25-45 N/mm²) and creep deformation ratio (10-30%) to achieve an optimal balance where the change rate between static and dynamic frictional forces is 15% or less, providing both riding comfort and driving stability simultaneously
Solution Approach 2:
The patent applies different materials with specific properties to different functional requirements within the sliding layer: resin material for low friction and comfort, porous metal for structural integrity and stability, and solid lubricant for wear resistance, creating local quality variations that satisfy both comfort and stability requirements
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 sliding member maintains a small difference between static and dynamic frictional forces, enhancing riding comfort and driving stability by adjusting Martens hardness and creep deformation ratio within specific ranges.
Implementation Method 1
a sliding member in which a difference between a static frictional force and a dynamic frictional force of a sliding surface is small
Implementation Method 2
regardless of a degree of progress of wear
Data Source
AI summary
A sliding member comprising a back metal layer, and a sliding layer, wherein the sliding layer contains a resin material, a surface of the sliding layer is an exposed sliding surface, and the sliding layer has Martens hardness of 25 to 45 N/mm2 and a creep deformation ratio of 10% to 30%.