Fuel Distributor Retainer Damping Element

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Solution Overview

Problem

Existing holders for fastening fuel distributors in internal combustion engines face issues with material fatigue due to uneven loading and high peak loads, leading to inadequate vibration damping and noise reduction over the engine's service life.

Innovation Solution

A damping element with a rigid inner and outer metallic layer and a viscoelastic damping layer in between, designed to dissipate vibration energy through shear stress, reducing material stress and ensuring consistent damping performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If damping rings made of elastomer are used in existing holders, then vibration damping is provided, but the material becomes fatigued over service life due to heavy stress and peak loads

Engineering Contradiction:
Improvevibration dampingVSAvoidmaterial fatigue resistance
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The damping element uses a composite structure with a viscoelastic damping layer sandwiched between two rigid metallic layers. This composite design allows the viscoelastic material to dissipate vibrations while the rigid metallic layers bear the mechanical loads and protect the damping material from fatigue, resolving the contradiction between providing vibration damping and preventing material fatigue.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different layers of the damping element have different material properties optimized for specific functions: the rigid metallic layers provide structural strength and load-bearing capacity, while the viscoelastic damping layer provides vibration dissipation. This local differentiation of material qualities allows each layer to perform its specialized function without suffering from the limitations of the other.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If the damping layer is made entirely of viscoelastic material, then vibration energy can be dissipated, but the material cross-section is small and stress concentration occurs

Engineering Contradiction:
Improvevibration energy dissipationVSAvoidstress concentration
Core Design Contradiction:
Object-affected harmful factorsVSStress or pressure

Solution Approach 1:

The composite structure distributes mechanical stresses across the rigid metallic layers while the viscoelastic damping layer focuses on energy dissipation through shear deformation. The rigid layers have larger cross-sections that bear the primary mechanical loads, preventing stress concentration in the viscoelastic material.

Inventive Principle:
Principle #40Composite materials

3Strength

If the fuel distributor is rigidly seated on the add-on structure, then functional strength requirements are met, but vibration-related damping and noise reduction are restricted

Engineering Contradiction:
Improvefunctional strengthVSAvoidvibration damping
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The damping element creates a semi-rigid connection that maintains structural strength through the rigid metallic layers while allowing vibration damping through the viscoelastic layer. This composite connection provides both the strength required for functional requirements and the vibration damping capability needed to reduce noise and vibrations.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The damping element changes the mechanical parameters of the connection by introducing a viscoelastic layer that provides both stiffness for strength requirements and damping characteristics for vibration reduction. This parameter modification allows the connection to simultaneously meet strength and damping requirements.

Inventive Principle:
Principle #35Parameter changes

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 provides improved vibration damping and noise reduction, maintaining the fuel distributor's rigid position while preventing material fatigue, thus effectively reducing structure-borne noise and vibration loads on components.

Implementation Method 1

a viscoelastic damping layer (38) arranged between the inner layer (36) and the outer layer (37)

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 2

designed to dissipate vibration energy through shear stress

Methodology Applied
Scientific EffectShear stress: Shear Stress

Data Source

PatentEP2864625B1Retainer for mounting a fuel distributor on an internal combustion engine and fuel injection system with such a retainer
Publication Date: 2018.04.04 ROBERT BOSCH GMBH
  • EP2864625B1 patent drawingFigure 1
  • EP2864625B1 patent drawingFigure 2~3
  • EP2864625B1 patent drawingFigure 4

AI summary

A holder used for mounting at least one component on an add-on structure, e.g., an internal combustion engine, includes: a base element able to be connected to a component; a fixation element, which extends through the through bore of the base element and a damping element disposed in the through bore, in order to mount the base element on the add-on structure; a fixation sleeve; and a damping element surrounding an outer side of the fixation sleeve and form-fittingly connected to the fixation sleeve on at least one side along the longitudinal axis, and on at least one side the damping element is form-fittingly connected to the base element along the longitudinal axis.