Low-Absorption Resin Power Transmission Member for Cold Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Resin-based power transmission members in seat belt systems face performance instability due to water absorption characteristics and strength decreases in low-temperature environments, with existing patents lacking detailed descriptions for manufacturing these components.
Innovation Solution
A resin power transmission member with a water absorption rate of 1% or less and mechanical characteristics such as tensile yield stress of 40 to 54 MPa, tensile fracture strain of 50% or more, tensile elastic modulus of 1200 to 1900 MPa, and unnotched Charpy impact strength of no fracture at −30° C. or higher, using a polyacetal homopolymer base resin and an elastomer, is developed, along with a method for manufacturing that selects the base resin by water absorption characteristics and determines elastomer composition based on mechanical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a resin-based power transmission member is used to transmit power to the gear while being plastically deformed, then the device complexity is reduced and ease of manufacture is improved, but the reliability deteriorates due to performance fluctuation based on water absorption characteristics and strength decrease in low-temperature environments
Solution Approach 1:
The patent applies parameter changes by precisely controlling the water absorption rate (1% or less) and mechanical properties (tensile yield stress 40-54 MPa, tensile fracture strain 50% or more, tensile elastic modulus 1200-1900 MPa, bending elastic modulus 1100-1700 MPa, unnotched Charpy impact strength no fracture at -30°C or higher) of the resin material to resolve the contradiction between ease of manufacture and reliability
Solution Approach 2:
The patent uses composite materials by combining base resin with specific elastomers to create a power transmission member that achieves both manufacturability and reliable performance across varying environmental conditions, particularly regarding water absorption and low-temperature strength
2Reliability
If the water absorption rate of the base resin is reduced to stabilize performance, then the reliability is improved, but the mechanical characteristics such as tensile yield stress and impact strength may deteriorate
Solution Approach 1:
The patent resolves this contradiction by creating a composite material system where base resin with low water absorption (1% or less) is combined with specifically selected elastomers that provide the necessary mechanical strength and toughness, achieving both reliability and strength requirements simultaneously
Solution Approach 2:
The patent applies parameter changes by optimizing the elastomer composition and content to achieve the desired balance between water absorption resistance and mechanical properties, specifically targeting tensile yield stress of 40-54 MPa and unnotched Charpy impact strength of no fracture at -30°C or higher
3Ease of operation
If the tensile fracture strain is increased to 50% or more to improve deformability for power transmission, then the power transmission capability is improved, but the tensile elastic modulus may decrease affecting structural stability
Solution Approach 1:
The patent resolves this contradiction by precisely controlling the parameter range of tensile elastic modulus (1200-1900 MPa) while maintaining high tensile fracture strain (50% or more) through optimized elastomer selection and composition, achieving both deformability for power transmission and structural stability
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 stabilizes the performance of the power transmission member across various environments, ensuring reliable operation in seat belt systems by minimizing water absorption and maintaining mechanical integrity at low temperatures.
Implementation Method 1
an elastomer that imparts mechanical characteristics, and as the mechanical characteristics, tensile yield stress (ISO 527) is 40 to 54 MPa, tensile fracture strain (ISO 527) is 50% or more, tensile elastic modulus (ISO 527) is 1200 to 1900 MPa, bending elastic modulus (ISO 178) is 1100 to 1700 MPa
Implementation Method 2
a power transmission member that is made of resin and transmits power to a gear while being plastically deformed
Data Source
AI summary
A power transmission member including a base resin that has a water absorption characteristic that a water absorption rate is 1% or less when Method 1 of ISO 62 (a method for measuring a weight increasing rate after being immersed in water at 23° C. for 24 hours) is used and an elastomer that imparts mechanical characteristics to the power transmission member 32a, in which as the mechanical characteristics, tensile yield stress (ISO 527) is 40 to 54 MPa, tensile fracture strain (ISO 527) is 50% or more, tensile elastic modulus (ISO 527) is 1200 to 1900 MPa, bending elastic modulus (ISO 178) is 1100 to 1700 MPa, and unnotched Charpy impact strength (ISO 179) is no fracture at −30° C. or higher.