Fuel Injector Retaining Element for Noise Isolation

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Solution Overview

Problem

Existing high-pressure fuel injection systems for internal combustion engines have complex and numerous fastening elements, making initial assembly and potential disassembly during service cumbersome, and they often result in direct metallic contact between the fuel injector and the cylinder head, leading to noise transmission.

Innovation Solution

A simplified fastening system using a retaining element with non-parallel legs that pivot to create a clamping force, allowing radial tolerance compensation and reducing noise transmission by eliminating direct metallic contact, featuring a form fit and clamping mechanism to secure the fuel injector to the cup, which can be made from bent and embossed sheet metal for cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional fastening elements are used to secure the fuel injector, then the fuel injector can be firmly fixed, but the number and complexity of fastening elements increases

Engineering Contradiction:
Improvefixing reliabilityVSAvoidfastening element complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple fastening functions into a single integrated retaining element. This retaining element simultaneously provides mechanical retention, noise isolation, and positioning functions that were previously distributed across multiple separate components, thereby reducing fastening element complexity while maintaining fixing reliability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The retaining element is designed as a multi-functional component that serves multiple purposes: it secures the fuel injector mechanically, provides acoustic isolation through material selection, and enables radial tolerance compensation. This multi-functionality eliminates the need for separate fastening elements, reducing overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If direct metallic contact is used between fuel injector and cylinder head, then the structure is simple, but noise transmission increases

Engineering Contradiction:
Improvestructural complexityVSAvoidnoise transmission
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an acoustic isolation element as an intermediary between the fuel injector and the cylinder head. This element, made from elastomeric or polymeric materials, acts as a mediator that transmits mechanical forces while blocking noise transmission, thus reducing harmful noise without significantly increasing structural complexity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The retaining element is constructed from composite or specially selected materials that combine mechanical strength for fastening with acoustic damping properties. This use of composite materials allows the single component to fulfill both structural and acoustic isolation functions, addressing noise transmission without adding complex multi-component structures

Inventive Principle:
Principle #40Composite materials

3Reliability

If multiple fastening elements are used, then the fuel injector can be securely held, but assembly and disassembly effort increases

Engineering Contradiction:
Improveholding securityVSAvoidassembly ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

By merging multiple fastening functions into a single retaining element, the patent reduces the number of assembly and disassembly operations required. The single component design maintains secure holding of the fuel injector while significantly simplifying the assembly process, as technicians no longer need to manipulate multiple separate fastening elements

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs homogeneous material properties within the retaining element to ensure uniform mechanical behavior and simplified assembly. The consistent material characteristics throughout the single component facilitate easier handling and installation compared to assemblies with multiple heterogeneous fastening elements

Inventive Principle:
Principle #33Homogeneity

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

This solution reduces the complexity and number of fastening elements, enabling easier assembly and disassembly while effectively isolating noise sources, allowing for radial tolerance compensation and increased load capacity suitable for higher operating pressures.

Implementation Method 1

The first leg and the second leg are not oriented parallel to one another in an initial state. The first leg and the second leg of the holding element are at least partially pivoted in order to clamp the holding element in the at least one recess.

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a hold-down device is provided between the fuel injector and the connecting piece. The hold-down device is designed as a bow-shaped component.

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2841759B1High pressure fuel injection arrangement
Publication Date: 2021.07.28 ROBERT BOSCH GMBH
  • EP2841759B1 patent drawingFigure 1~2
  • EP2841759B1 patent drawingFigure 3~4
  • EP2841759B1 patent drawingFigure 5~6

AI summary

The invention relates to an arrangement (1) which is used in particular as a fuel injection system for high-pressure fuel injection in internal combustion engines, comprising a fuel distributor and multiple fuel injection valves. Each of the fuel injection valves is arranged on a cup (2) of the fuel distributor. At least one of the fuel injection valves is secured to the corresponding cup (2) by a retaining element (4). The retaining element (4) has a first limb (5) which is at least substantially straight and a second limb (6) which is at least substantially straight. The cup (2) has at least one recess (7, 8) which extends through a wall (9) of the cup (2). The first limb (5) and the second limb (6) are guided through the at least one recess (7, 8). Furthermore, the connecting sleeve (3) of the fuel injection valve has a collar (15) which is supported on the first limb (5) of the retaining element (4) and on the second limb (6) of the retaining element (4) in order to secure the fuel injection valve to the cup (2). In this manner, the fuel injection valve can be reliably secured to the cup (2).