Fuel Injection Filter With Segmented Filtration Zones

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Solution Overview

Problem

Fuel injectors in high-pressure common rail fuel injection systems are susceptible to debris and impurities, which can erode sealing surfaces, obstruct nozzles, and reduce injector performance and lifespan due to the inability of existing filters to effectively remove particulates at various sizes.

Innovation Solution

A filter with multiple filtration zones, including a first filtration zone defined by an edge and a second filtration zone with perforated portions, positioned within the inlet channel of the fuel injector to filter particulates of different sizes, ensuring clean fuel delivery and preventing clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single-stage filter is used in the fuel injection system, then the device complexity is reduced, but the filtration effectiveness for different sized particulates is insufficient

Engineering Contradiction:

Improvefiltration effectivenessVSAvoidfilter structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The filter is divided into multiple filtration zones with different filtration mechanisms. The first filtration zone uses an edge filter structure to capture larger particulates, while the second filtration zone uses a perforated structure to capture smaller particulates. This segmentation allows each zone to specialize in filtering specific size ranges, improving overall filtration effectiveness without requiring a completely separate filter for each function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the filter are designed with different structural properties to address local filtration needs. The edge portion of the filter body provides one type of filtration (first filtration zone), while the perforated portions provide another type of filtration (second filtration zone). Each local region is optimized for its specific function, allowing the filter to handle a broader range of particulate sizes effectively.

Inventive Principle:

Principle #3Local quality

2Reliability

If existing filters are used, then the device complexity remains low, but debris and impurities erode sealing surfaces and obstruct nozzles

Engineering Contradiction:

Improveinjector performanceVSAvoiddebris and impurities

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The filter is positioned in the fuel flow path upstream of the fuel injector components to perform preliminary filtration before fuel reaches critical areas. By removing particulates early in the fuel flow path, the filter prevents debris from reaching and damaging sealing surfaces and nozzles, extending injector life and maintaining performance.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The filter acts as an intermediary component between the fuel source and the fuel injector components. It intercepts and removes harmful particulates from the fuel, providing a protective barrier that prevents direct contact between debris and sensitive injector components like sealing surfaces and nozzles.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If no filtration is provided, then the device complexity is minimized, but fuel-borne debris interferes with fuel injection events

Engineering Contradiction:

Improvefiltration system complexityVSAvoidinjection accuracy

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

Rather than attempting to filter all possible particulate sizes with a single complex filter, the design uses multiple filtration zones that collectively provide sufficient filtration for the critical size ranges. The first zone handles larger particulates and the second zone handles smaller particulates, providing partial filtration actions that together achieve the necessary level of fuel cleanliness for accurate injection.

Inventive Principle:

Principle #16Partial or excessive action

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 two-stage filtration system effectively removes particulates greater than 75 μm and 1 mm × 65 μm × 65 μm, extending injector life, improving injection accuracy and efficiency by maintaining component tolerances and preventing fuel-borne debris from interfering with fuel injection events.

Implementation Method 1

The edge and an inlet channel of the fuel injection system are adapted to define a first filtration zone

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 2

the perforated portion defines a second filtration zone

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentUS10267281B2Filter for fuel injection systems

Publication Date: 2019.04.23 CATERPILLAR INC

AI summary

A filter for a fuel injection system includes a body that defines a longitudinal axis, a first end face, a second end, an outer surface extending between the first end face and the second end, an inner surface defining an inner chamber closed at the first end face and open at the second end. The body also defines at least one perforated portion formed in the outer surface extending from the outer surface to the inner surface, at least one slot extending axially along the outer surface. The slot is open and is in fluid communication with the first end face and defines an edge along the outer surface. The edge provides fluid communication between the slot and the perforated portion. Additionally, the edge and an inlet channel of the fuel injection system are adapted to define a first filtration zone. The perforated portion defines a second filtration zone.