Electromagnetic Fuel Injector Closing Disk with Elastic Sealing Rims

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Solution Overview

Problem

Existing electromagnetic fuel injectors face challenges in increasing fuel flow rate without escalating the size, weight, cost, and energy consumption of the electromagnetic actuator, as enlarging the through hole in the closing disk increases hydraulic/pneumatic force, and raising fuel pressure also requires increased electromagnetic force.

Innovation Solution

The design incorporates a closing disk with elastic material for sealing rims and a metal outer portion, allowing for elastic deformation to ensure sealing and reduce constructional precision, along with a distributed injection nozzle structure to maintain hydraulic/pneumatic force while enhancing fuel flow rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the size of the through hole made through the closing disk is increased, then the rate of fuel that flows through the injection nozzle is improved, but the hydraulic/pneumatic force that pushes the open/close element against the closing disk increases, requiring increased electromagnetic force

Engineering Contradiction:
Improvefuel flow rateVSAvoidhydraulic/pneumatic force
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The closing disk is segmented into two distinct material zones: a metal outer portion providing structural strength and an elastic inner portion providing sealing. This segmentation allows the through hole to be enlarged for higher fuel flow while the elastic material compensates for pressure variations, maintaining sealing without requiring proportionally increased electromagnetic force.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the physical parameters of the closing disk by introducing elastic material with specific elastic modulus characteristics. This parameter change allows the sealing surface to deform elastically under hydraulic/pneumatic pressure, maintaining tight sealing even with larger through hole areas that would otherwise require significantly higher electromagnetic forces to counteract the increased pressure differential.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the pressure of supply of the fuel is increased, then the rate of fuel that flows through the injection nozzle is improved, but the hydraulic/pneumatic force that pushes the open/close element against the closing disk increases, requiring increased electromagnetic force

Engineering Contradiction:
Improvefuel flow rateVSAvoidhydraulic/pneumatic force
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The patent changes the physical parameters of the closing disk by introducing elastic material with specific elastic modulus characteristics. This parameter change allows the sealing surface to deform elastically under hydraulic/pneumatic pressure, maintaining tight sealing even with larger through hole areas that would otherwise require significantly higher electromagnetic forces to counteract the increased pressure differential.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The closing disk uses a composite structure combining metal and elastic materials. The metal outer portion provides structural integrity to withstand high fuel supply pressures, while the elastic inner portion provides compliant sealing that adapts to pressure variations. This composite approach enables high fuel flow rates at elevated pressures without requiring proportional increases in electromagnetic actuator force.

Inventive Principle:
Principle #40Composite materials

3Strength

If the closing disk is made entirely of metal, then the structural strength is improved, but the sealing precision deteriorates due to inability to compensate for tolerances and deformation

Engineering Contradiction:
Improvestructural strengthVSAvoidsealing precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The closing disk uses a composite structure combining metal and elastic materials. The metal outer portion provides structural integrity to withstand high fuel supply pressures, while the elastic inner portion provides compliant sealing that adapts to pressure variations. This composite approach enables high fuel flow rates at elevated pressures without requiring proportional increases in electromagnetic actuator force.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The closing disk applies different material qualities to different regions: the outer portion uses rigid metal for structural strength while the inner portion uses elastic material for sealing precision. This local differentiation of material properties allows each region to perform its specific function optimally - the metal provides overall strength while the elastic material ensures precise sealing by compensating for manufacturing tolerances and pressure-induced deformations.

Inventive Principle:
Principle #3Local quality

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 design achieves a high fuel flow rate with reduced hydraulic/pneumatic force and lower production costs, as the elastic material compensates for tolerances and the distributed nozzle structure maintains force balance, optimizing fuel supply and injector efficiency.

Implementation Method 1

the closing disk (9) comprises an inner portion (14), which is made of elastic material, constitutes a top part of the through holes (10) and defines the seal rims (12)

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

an electromagnetic actuator (7), governed to displace the open/close element (11) from the closing position to the opening position

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnetic Induction

Data Source

PatentEP2253827B1Electromagnetic fuel injector
Publication Date: 2012.05.09 FAB ITAL MAGNETI MARELLI SPA
  • EP2253827B1 patent drawingFigure 1
  • EP2253827B1 patent drawingFigure 2
  • EP2253827B1 patent drawingFigure 3

AI summary

An electromagnetic fuel injector (1) provided with: a tubular body (4), which has a cylindrical seat (5) that performs the function of fuel pipe; an injection nozzle (3) regulated by an injection valve (8); a closing disk (9), which forms part of the injection valve (8), is laterally fixed to the tubular body (4), and has a through hole (10) that defines the injection nozzle (3); a mobile open/close element (11), which forms part of the injection valve (8) and is mobile away from/towards the closing disk (9) for regulating the flow of fuel; and an electromagnetic actuator (7), which is designed to displace the open/close element (11) between a closing position and an opening position of the injection valve (8); the closing disk (9) has a plurality of through holes (10) that together define the injection nozzle (3); and present around each hole (10) is an annular sealing rim (12), which juts out from the closing disk (9), surrounds the hole (10), and in the closing position is in contact with a bottom surface (13) of the open/close element (11).