Fuel Injector Support Disk for Secure Rail Pre-Assembly

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Solution Overview

Problem

Fuel injectors in internal combustion engines face issues of accidental dislodgment during transport and handling due to vibrations and forces, which can lead to improper sealing and potential fuel leakage, especially when pre-assembled in a compact structural unit before final installation on the cylinder head.

Innovation Solution

A radial support disk is arranged on the inlet connection of the fuel injector, featuring alternating pressing areas and a slot for easy attachment and tolerance compensation, preventing axial slippage and ensuring secure retention on the fuel distribution line during transport and assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sealing ring is used to seal the inlet nozzle against the fuel distribution line, then sealing is achieved, but the fuel injector can still accidentally dislodge during transport and handling

Engineering Contradiction:
Improvesealing reliabilityVSAvoidposition stability during transport
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

A radial support disk is introduced as an intermediary component between the inlet nozzle and the fuel distribution line. This disk provides both sealing support and mechanical retention through engagement features (lugs or clips) that prevent axial displacement, while the sealing ring maintains the seal. The radial support disk acts as a mediator that simultaneously addresses both sealing and position stability requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the radial support disk has a large outer diameter to prevent dislodgment, then retention is improved, but the pressing force during assembly increases

Engineering Contradiction:
Improveretention stabilityVSAvoidpressing stress during assembly
Core Design Contradiction:
Stability of the object's compositionVSStress or pressure

Solution Approach 1:

The outer circumference of the radial support disk is segmented into alternating pressing areas and non-pressing areas. The pressing areas (with larger radius) provide retention stability by engaging with the fuel distribution line, while the non-pressing areas (with smaller radius) reduce the overall pressing force during assembly. This segmentation allows the disk to maintain its retention function while minimizing assembly stress.

Inventive Principle:
Principle #1Segmentation

3Stability of the object's composition

If the radial support disk is made rigid to prevent tilting, then position stability is improved, but the difficulty of mounting increases

Engineering Contradiction:
Improvetilt preventionVSAvoidmounting ease
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The radial support disk incorporates a slot that runs axially through it, transforming the rigid structure into a slightly flexible component. This slot allows the disk to deform elastically during mounting, enabling it to pass through the receiving opening more easily. Once mounted, the disk returns to its rigid state, providing tilt prevention and position stability. The dynamic flexibility during assembly resolves the contradiction between rigidity for stability and flexibility for ease of mounting.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3662156B1Fuel injection valve
Publication Date: 2024.02.21 ROBERT BOSCH GMBH
  • EP3662156B1 patent drawingFigure 1
  • EP3662156B1 patent drawingFigure 2
  • EP3662156B1 patent drawingFigure 3~4

AI summary

The fuel injection valve (1) according to the invention is in particular characterized in that it is can be pre-mounted in a receiving opening (12) of a fuel distribution line (4) in a structural unit as a fuel charge assembly so as to be loss-proof for transport to final assembly at the vehicle manufacturer. To this end, a radial support disk (30) is arranged at the inflow-side end (3) of the inflow connecting piece (7) for loss-proofing the fuel injection valve (1) by pressing the radial support disk (30) in the receiving opening (12). The fuel injection valve is particularly suitable for the direct injection of fuel into a combustion chamber of a mixture-compressing spark-ignited internal combustion engine.