Fuel Rail Coupling Device With Metal And Plastic Spring Elements
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Solution Overview
Problem
Existing coupling devices for fuel rails and cylinder heads in combustion engines face challenges in minimizing pressure fluctuations and noise transmission, while ensuring reliable and precise mechanical coupling.
Innovation Solution
A coupling device featuring metal first spring elements to control fuel injector cup displacement and plastic second spring elements to compensate component tolerances, allowing for noise reduction and precise assembly without direct contact between the cylinder head and fuel rail components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If rigid fastening is used to ensure precise mechanical coupling, then mechanical strength is improved, but noise transmission and mechanical stress increase
Solution Approach 1:
The patent applies beforehand cushioning by introducing spring elements (both metallic and plastic) between the fastening elements and the fuel rail/cylinder head components. These spring elements are pre-installed to absorb mechanical stresses and dampen vibrations before they can propagate as noise, thereby maintaining strong mechanical coupling while reducing noise transmission.
Solution Approach 2:
The spring elements serve as intermediary components between the rigid fastening elements and the fuel rail/cylinder head. These intermediaries decouple the direct rigid connection, allowing the fastening elements to maintain mechanical strength while the spring elements absorb vibrations and reduce noise transmission to the surrounding components.
2Object-affected harmful factors
If spring elements are introduced to reduce noise, then noise transmission is minimized, but assembly precision and tolerance compensation become more complex
Solution Approach 1:
The patent segments the cushioning function into two distinct types of spring elements: metallic spring elements for primary structural support and vibration absorption, and plastic spring elements for secondary tolerance compensation and fine-tuning. This segmentation allows each material type to optimize its specific function while collectively achieving both noise reduction and assembly precision.
Solution Approach 2:
The patent employs composite materials by combining metallic and plastic spring elements in the same assembly. The metallic springs provide high strength and elasticity for major vibration damping, while the plastic springs offer flexibility for tolerance compensation. This composite approach enables simultaneous achievement of noise reduction and precise assembly without increasing complexity.
3Manufacturing precision
If metal spring elements are used for fuel injector cup fastening, then displacement control is improved, but weight increases
Solution Approach 1:
The patent applies local quality by using metal spring elements specifically at the fuel injector cup fastening locations where precise displacement control is critical for injection accuracy. In contrast, plastic spring elements are used at other fastening points where tolerance compensation is needed but high precision displacement control is less critical. This localized material selection optimizes performance while minimizing overall weight.
Solution Approach 2:
The patent changes material parameters by selecting different materials (metal vs. plastic) based on the specific functional requirements of each fastening location. The metal spring elements have higher elastic modulus and strength for precise displacement control, while plastic elements have appropriate flexibility for tolerance compensation. This parameter-based material selection achieves optimal performance-to-weight ratio.
4Adaptability or versatility
If plastic spring elements are used for support element fastening, then tolerance compensation is improved, but load-bearing capacity decreases
Solution Approach 1:
The patent segments the load-bearing and tolerance-compensation functions between different spring element types. The metallic spring elements are positioned to handle primary load-bearing requirements, while the plastic spring elements are positioned to provide tolerance compensation and fine-adjustment. This functional segmentation allows each material to operate within its optimal performance range.
Solution Approach 2:
The patent applies partial action by having the plastic spring elements handle only the tolerance compensation portion of the mechanical coupling, while the metallic spring elements handle the majority of the load-bearing function. This division of labor allows the plastic elements to be optimized for flexibility and tolerance accommodation without requiring them to bear full loads.
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 minimizes mechanical stress and noise transmission, ensuring reliable and precise coupling while maintaining low pressure fluctuations, thereby enhancing fuel injection precision and reducing component wear.
Implementation Method 1
at least one first spring element being arranged between the first fastening element and the fuel injector cup and/or being arrangeable between the fuel injector cup and the cylinder head, wherein the at least one first spring element consists of a metal or comprises a metal
Implementation Method 2
at least one second spring element being arranged between the second fastening element and the support element and/or being arrangeable between the support element and the cylinder head, wherein the at least one second spring element consists of a plastic or comprises a plastic
Data Source
AI summary
A coupling device for coupling a fuel rail to a cylinder head of a combustion engine may include: a fuel injector cup coupled to the fuel rail and facing the cylinder head, a first fastening element facing the fuel injector cup and fixedly coupled to the cylinder head, at least one first spring element arranged between the first fastening element and the fuel injector cup and/or between the fuel injector cup and the cylinder head, a support element arranged between the fuel rail and the cylinder head and fixedly coupled to the fuel rail, a second fastening element engaged with the support element and fixedly coupled to the cylinder head, and at least one second spring element arranged between the second fastening element and the support element and/or between the support element and the cylinder head. The first spring element(s) may comprise metal, and the second spring element(s) may comprise plastic.