Multi-Cylinder Diesel Engine Common Rail Cooling Layout

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Solution Overview

Problem

In multi-cylinder diesel engines, the placement of the air intake portion in front of the common rail blocks engine cooling air, leading to low heat radiation for the common rail and resulting in thermal damage and excessive fuel temperature rises.

Innovation Solution

The air intake portion of the intake manifold is relocated laterally outward of the common rail, allowing engine cooling air to be blown directly onto the common rail, enhancing heat radiation, and the fuel supply pump is positioned to receive cooling air for improved heat dissipation, while a power takeoff portion is placed rearward of the pump driving chamber to maintain pump accuracy and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the air intake portion is placed in front of the common rail, then the structure is compact and easy to manufacture, but the engine cooling air is blocked and heat radiation from the common rail is reduced

Engineering Contradiction:
Improvestructural simplicityVSAvoidcommon rail temperature
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The air intake portion is repositioned from a front-facing location to a lateral position beside the common rail, changing the spatial arrangement from longitudinal to lateral. This dimensional repositioning allows cooling air to flow along the lateral surface of the common rail without being blocked by the air intake structure, thereby maintaining effective heat radiation while preserving structural compactness.

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

2Device complexity

If the air intake portion blocks the cooling air path, then the engine structure is simplified, but thermal damage to the common rail and fuel temperature rise occur

Engineering Contradiction:
Improveair intake arrangementVSAvoidcommon rail thermal damage resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The air intake portion is relocated to the lateral side of the common rail, changing the airflow path from a front-to-back direction to a lateral flow direction. This repositioning in another dimension allows the air intake and cooling functions to coexist without interference, maintaining device simplicity while preventing thermal damage by ensuring continuous cooling air supply to the common rail.

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

3Temperature

If the common rail is positioned to receive cooling air directly, then heat radiation is enhanced and thermal damage is prevented, but the air intake portion requires lateral repositioning which increases design complexity

Engineering Contradiction:
Improvecommon rail cooling efficiencyVSAvoidair intake positioning
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The air intake portion is repositioned laterally beside the common rail, utilizing the lateral dimension rather than the front-facing position. This repositioning creates an unobstructed lateral airflow path that directly cools the common rail, enhancing heat radiation efficiency. The lateral arrangement actually simplifies the design by eliminating the need for complex airflow routing around obstructions.

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

This configuration enhances heat radiation for both the common rail and fuel supply pump, preventing thermal damage and excessive fuel temperature rises, while maintaining pump accuracy and durability.

Implementation Method 1

the common rail is disposed in a region to which engine cooling air produced by the engine cooling fan is blown

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

the heat radiation of the common rail is enhanced

Methodology Applied
Scientific EffectThermal Radiation: Thermal Radiation

Data Source

PatentEP2295783B1Multi-cylinder diesel engine
Publication Date: 2016.05.18 KUBOTA CORP
  • EP2295783B1 patent drawingFigure 1
  • EP2295783B1 patent drawingFigure 2
  • EP2295783B1 patent drawingFigure 3

AI summary

A multi-cylinder diesel engine which has a common rail (3) extending in a fore-and-aft direction and is disposed above an intake manifold (2), and an engine cooling fan 4 is disposed at the front of the engine. A air intake portion (6) of the intake manifold (2) is disposed laterally outwardly of the common rail 3 and opposite a head cover (5). The common rail 3 is disposed in the path of cooling air blown by the engine cooling fan (4).