Gas-Filled Pressure Pulsation Damper for Fuel Injection Systems

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Solution Overview

Problem

Fuel injection systems face mechanical stress and efficiency issues due to pressure pulsations, which can damage components and impair the filtering effect of fuel filters, and existing solutions like overflow valves reduce upstream pressure, affecting high-pressure pump efficiency.

Innovation Solution

A pressure pulsation damper with a tubular line section and a pressure damping chamber filled with gas, connected via shell-side openings, absorbs pressure peaks, reducing mechanical stress and enhancing pump filling efficiency by releasing energy back into the system during pressure drops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If an overflow valve is used to dampen pressure pulsations, then pressure peaks are reduced, but upstream pressure is reduced affecting high-pressure pump filling efficiency

Engineering Contradiction:
Improvepressure peaksVSAvoidhigh-pressure pump filling efficiency
Core Design Contradiction:
Stress or pressureVSProductivity

Solution Approach 1:

A gas-filled pressure damping chamber is introduced as an intermediary element between the fuel injection system components. The gas volume absorbs pressure pulsations through compression and expansion, acting as a mediator that dampens pressure peaks without creating a permanent pressure drop like an overflow valve. This allows the high-pressure pump to maintain adequate upstream pressure for efficient filling while still protecting downstream components from pressure surges.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention utilizes pneumatic principles by employing a compressible gas volume in the pressure damping chamber. The gas acts as a hydraulic-pneumatic cushion that absorbs and releases energy dynamically, contrasting with the purely hydraulic overflow valve approach. This pneumatic element provides elastic energy storage and release, dampening pressure pulsations while maintaining system pressure levels necessary for pump operation.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Productivity

If pressure pulsations are allowed to propagate through the fuel system, then pump filling is maintained, but mechanical stress damages components and backwashes fuel filters

Engineering Contradiction:
Improvepump fillingVSAvoidmechanical stress on components
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention converts the harmful pressure pulsations into a beneficial energy absorption mechanism. The gas-filled pressure damping chamber captures the harmful pressure energy through gas compression, transforming the harmful mechanical stress into stored pneumatic energy. This energy is then gradually released, preventing the harmful effects of pressure peaks on filters and components while maintaining overall system productivity.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The pressure damping chamber with its compressible gas volume provides beforehand cushioning against pressure pulsations. The gas acts as a pre-positioned energy buffer that is already in place to absorb incoming pressure shocks before they can propagate through the system and cause damage to filters and other sensitive components.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Stress or pressure

If a traditional pressure damper design is used, then pressure pulsations are dampened, but integration into the fuel injection system is complex and expensive

Engineering Contradiction:
Improvepressure pulsation dampingVSAvoidintegration complexity
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The pressure damping chamber is merged with the existing fuel line structure, forming an integrated component rather than a separate auxiliary device. The tubular line section with shell-side openings combines the fuel passage and pressure damping functions in a single integrated unit, simplifying installation and reducing system complexity while maintaining effective pressure pulsation damping.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pressure damping chamber serves multiple functions simultaneously: it acts as a fuel passage conduit, a pressure damping element, and an energy absorption chamber. This multi-functionality eliminates the need for separate components for each function, reducing overall device complexity and integration difficulty in the fuel injection system.

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

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 dampens pressure pulsations, reducing mechanical stress on fuel injection system components, preventing filter backwashing, and improving high-pressure pump efficiency by absorbing and releasing energy, thus increasing system robustness and optimal filter performance.

Implementation Method 1

pressure peaks bring about a compression of a gas volume in the pressure damping chamber, so that the pressure peaks are damped or compensated for

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

If the pressure in the system then drops again, for example during the intake phase of a high-pressure pump in the fuel injection system, the energy absorbed by the gas is released back into the fuel

Methodology Applied
Scientific EffectElastic energy release: Elasticity

Data Source

PatentEP3353410B1Pressure pulsation damper for a fuel injection system, and fuel injection system
Publication Date: 2019.10.16 ROBERT BOSCH GMBH
  • EP3353410B1 patent drawingFigure 1~2
  • EP3353410B1 patent drawingFigure 3~4

AI summary

The invention relates to a pressure pulsation damper (1) for a fuel injection system, in particular a common-rail injection system, comprising a tubular line section (2) in which a fuel duct (3) is formed, which line section is connected, by way of at least one opening (4) in the shell in the tubular line section (2), to a pressure damping chamber (5). According to the invention, the pressure damping chamber (5) is at least partially filled with gas (6) and/or comprises at least one gas-filled element (7). The invention also relates to a fuel injection system, in particular a common-rail injection system, having a pressure pulsation damper (1) of said type.