One-Piece Nozzle Body With 3D Printed Cooling Matrix

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Solution Overview

Problem

Existing fuel injector nozzle bodies with cooling channels require complex designs and manufacturing processes, leading to structural weakening and connection issues such as lack of tightness or reduced strength.

Innovation Solution

A one-piece nozzle body with optimized cooling channels produced using 3D printing, featuring a cooling matrix with a large convection surface, designed in shapes like fences, meanders, or spirals, and integrated with thermally conductive materials, eliminating the need for complex manufacturing techniques and seals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling channels are integrated into the nozzle body, then cooling effectiveness is improved, but manufacturing complexity increases and structural strength decreases

Engineering Contradiction:
Improvenozzle tip temperatureVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the cooling channels directly into the nozzle body as an integrated single-piece component, eliminating the need for separate cooling caps or additional parts. This integration is achieved through 3D printing technology, which allows complex internal cooling geometries to be manufactured within the nozzle body itself, thereby improving cooling effectiveness while avoiding the complexity of assembling multiple components with seals and connections.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes a cooling matrix with porous structure formed through 3D printing within the nozzle body. This porous cooling matrix provides extensive surface area for heat transfer while being integrated into the solid nozzle structure. The porous material allows efficient coolant flow and heat exchange without requiring complex external cooling systems, thus improving cooling effectiveness while maintaining manufacturing simplicity.

Inventive Principle:
Principle #31Porous materials

2Temperature

If cooling channels are added to the nozzle body, then cooling effectiveness is improved, but manufacturing effort increases

Engineering Contradiction:
Improvenozzle tip temperatureVSAvoidmanufacturing effort
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent changes the manufacturing parameter from traditional subtractive methods (turning, drilling) to additive manufacturing (3D printing). This parameter change enables the direct formation of complex internal cooling channel geometries within the nozzle body in a single manufacturing process, eliminating the need for multiple machining steps, tool changes, and complex fixture setups, thereby improving cooling effectiveness while reducing manufacturing effort.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The 3D printing process allows the nozzle body to self-form its internal cooling channels during manufacturing, without requiring external tooling or subsequent assembly operations. The cooling matrix is built layer-by-layer directly within the nozzle body structure, enabling the component to manufacture itself with its cooling features integrated, thus improving cooling effectiveness while minimizing manufacturing effort.

Inventive Principle:
Principle #25Self-service

3Temperature

If cooling channels are integrated into the nozzle body, then cooling effectiveness is improved, but connection reliability decreases

Engineering Contradiction:
Improvenozzle tip temperatureVSAvoidconnection tightness
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent merges the cooling channels and coolant supply connections directly into the nozzle body as an integrated structure. The coolant inlet and outlet channels are formed as continuous internal passages within the printed nozzle body, eliminating the need for separate coolant supply components, seals, or external connections. This integration improves cooling effectiveness while ensuring reliable, leak-free coolant flow paths without connection points that could fail.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts the cooling function from separate external components and integrates it directly into the nozzle body structure. By taking out the need for separate cooling caps, coolant supply lines, and sealing elements, the design eliminates potential connection failure points while maintaining effective cooling through internally formed channels, thus improving both cooling effectiveness and connection reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

4Temperature

If complex cooling channel geometries are manufactured using conventional methods, then cooling effectiveness is improved, but manufacturing complexity and structural weakening increase

Engineering Contradiction:
Improvenozzle tip temperatureVSAvoidnozzle body strength
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The patent changes the manufacturing parameter from conventional subtractive methods to additive manufacturing (3D printing). This enables the creation of complex, optimized cooling channel geometries that follow the heat flow paths within the nozzle body, maximizing cooling effectiveness. The additive process builds material rather than removing it, maintaining the nozzle body's structural integrity and strength while incorporating sophisticated internal cooling features that would be impossible or highly damaging to create through traditional machining.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes the third dimension in additive manufacturing to create complex, multi-level cooling channel geometries within the nozzle body structure. The cooling matrix is built layer-by-layer with intricate internal pathways that optimize heat transfer while maintaining external nozzle dimensions and structural strength. This dimensional approach allows cooling channels to be embedded within the nozzle body volume without compromising external integrity or requiring material removal that would weaken the structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 provides effective cooling of the nozzle tip, enhancing the robustness and service life of the fuel injector by maximizing heat transfer while avoiding connection problems and maintaining structural integrity.

Implementation Method 1

The cooling matrix has the largest possible total surface area effective for cooling, thus maximizing the heat transfer from the nozzle tip to the cooling medium

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

making the cooling of the nozzle body particularly effective

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP3475555B1Nozzle body for a fuel injector
Publication Date: 2020.10.28 ROBERT BOSCH GMBH
  • EP3475555B1 patent drawingFigure 1
  • EP3475555B1 patent drawingFigure 2
  • EP3475555B1 patent drawingFigure 3~4

AI summary

The invention relates to a nozzle body (16), in particular in use in a fuel injector (100) for injecting fuel into the combustion chamber of an internal combustion engine. The nozzle body (16) is made in one piece. The nozzle body (16) comprises a pressure chamber (8) which can be supplied, via a supply bore (64), with high-pressure fuel. A nozzle needle (6), which opens or closes at least one injection opening (60), is arranged in the pressure chamber (8) so as to be able to move longitudinally. The at least one injection opening (60) is formed in a nozzle tip (16a) of the nozzle body (16). Cooling channels (30), through which coolant can be made to flow, are formed in the nozzle body (16). The cooling channels (30) include a cooling matrix (35) formed in the nozzle tip (16a).