Connection piece for a fuel injector in an internal combustion engine

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Solution Overview

Problem

In common rail injection systems, pressure waves generated by the high-pressure pump propagate through fuel lines into injectors, disrupting uniform fuel flow.

Innovation Solution

A connector for fuel injectors with separate high-pressure channels for inlet and outlet connections, which are indirectly fluidically connected via an internal high-pressure accumulator, and include throttles in the supply channels to dampen pressure pulsations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate high-pressure channels with an internal accumulator and throttles are implemented, then pressure pulsations are dampened and fuel flow uniformity is improved, but device complexity increases

Engineering Contradiction:
Improvefuel flow uniformityVSAvoidconnector structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The high-pressure accumulator is integrated within the connector body, with supply channels and throttles nested inside the connector structure. This nesting approach dampens pressure pulsations while avoiding the need for separate external dampening components, thus improving fuel flow uniformity without proportionally increasing overall device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The internal high-pressure accumulator acts as an intermediary element between the high-pressure supply and the injector. It absorbs pressure pulsations generated by the pump before they reach the injector, while the throttles in the supply channels further mediate and dampen these fluctuations, ensuring uniform fuel flow to the injector.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If throttles are installed in high-pressure supply channels, then pressure pulsations are dampened, but pressure loss increases

Engineering Contradiction:
Improvepressure stabilityVSAvoidpressure loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

Throttles are installed in the supply channels, but their opening degree is optimized to provide sufficient damping of pressure pulsations while minimizing pressure loss. The throttle design applies partial restriction rather than complete closure, achieving the necessary pressure stabilization without excessive energy loss.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The connector design incorporates throttles that replicate the damping function previously requiring separate external components. By integrating the throttling function directly into the connector's supply channels, the system achieves pressure stabilization with minimized additional pressure loss that would occur with separate external dampening devices.

Inventive Principle:
Principle #26Copying

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 effectively eliminates or dampens pressure pulsations, preventing their transmission from one injector to another in a series connection, thereby ensuring uniform fuel flow.

Implementation Method 1

the transmission of these fluctuations from a first injector in the series connection to at least one downstream injector is prevented or at least reduced

Methodology Applied
Scientific EffectPressure pulsation damping: Damping

Implementation Method 2

via which channels the respective connections open separately from one another within an internal high-pressure accumulator

Methodology Applied
Scientific EffectHydraulic accumulation: Hydraulic Accumulator

Implementation Method 3

A variant in which a throttle is provided in only one of the two high-pressure supply channels is therefore conceivable

Methodology Applied
Scientific EffectFlow restriction: Pressure Drop

Implementation Method 4

By using at least one throttle within at least one of these high-pressure supply channels, the aforementioned pressure pulsations within the high-pressure lines can be dampened even more

Methodology Applied
Scientific EffectPressure pulsation damping: Damping

Data Source

PatentEP3827166B1Connection piece for a fuel injector in an internal combustion engine
Publication Date: 2025.06.18 LIEBHERR COMPONENTS DEGGENDORF GMBH
  • EP3827166B1 patent drawingFigure 1
  • EP3827166B1 patent drawingFigure 2
  • EP3827166B1 patent drawingFigure 3

AI summary

The invention relates to a connection piece (10) for a fuel injector in an internal combustion engine, comprising at least one high-pressure inlet port (A) and at least one high-pressure outlet port (B), said high-pressure inlet port (A) and said high-pressure outlet port (B) extending, via separate high-pressure feed channels (11A, 11B), into an internal high-pressure accumulator (15) of the connection piece and/or of the injector.