Fuel Pump Metering Valve With Axial-Radial Discharge Flow

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing metering valves for fuel pumps, such as those used in diesel engines, face challenges in increasing fuel flow without increasing design costs or modifying existing components, particularly due to restricted cross-sectional flow areas in lateral channels.

Innovation Solution

The metering valve design includes a plug-shaped piston with side openings that cooperate with the sleeve, and a plug with an axial through-hole and inset portions to increase the overall aperture for fuel discharge, ensuring proportional fuel flow and uniform spring load transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If lateral flow channels are used for fuel discharge, then the valve structure is simplified, but the cross-sectional flow area is restricted and hourly fuel flow cannot be increased

Engineering Contradiction:
Improvevalve structureVSAvoidhourly fuel flow
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The discharge path is segmented into multiple independent flow channels (central axial channel and multiple lateral flow channels) within the plug. This segmentation increases the total cross-sectional flow area while maintaining the compact valve structure, directly resolving the contradiction between structural simplicity and fuel flow capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from purely lateral flow channels to a three-dimensional discharge structure combining axial and radial flow paths. The central axial through-hole provides a vertical discharge dimension, while lateral openings provide radial discharge, creating multi-dimensional flow paths that significantly increase total flow area without increasing overall valve size.

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

2Productivity

If the number of lateral flow channels is increased to enhance fuel flow, then the discharge capacity is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvefuel discharge capacityVSAvoidplug structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Multiple flow channels (central axial channel and lateral openings) are merged into a single integrated plug structure. This consolidation achieves high discharge capacity through combined flow paths while avoiding the complexity of separate components, directly addressing the contradiction between discharge capacity and device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The plug serves multiple functions simultaneously: it acts as a flow distributor with multiple channels, a structural support element, and a sealing component. This multi-functionality increases discharge capacity through multiple flow paths while avoiding additional components, resolving the contradiction between productivity and device complexity.

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

3Reliability

If the spring load is increased to improve valve closing force, then the sealing performance is improved, but the uniformity of load distribution on the plug becomes difficult to maintain

Engineering Contradiction:
Improvevalve sealing performanceVSAvoidload distribution uniformity
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The plug incorporates asymmetric features including an inset portion with specific radius and an axial step that creates asymmetric load distribution surfaces. These asymmetric geometries are strategically designed to distribute spring load uniformly across the plug's contact surfaces, maintaining both sealing performance and load uniformity simultaneously.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Different regions of the plug have different geometric properties: the inset portion has a smaller radius than the contact portion, and an axial step creates localized load distribution zones. This local variation in geometry ensures uniform stress distribution under spring load while maintaining the overall plug structure, resolving the contradiction between sealing force and load uniformity.

Inventive Principle:
Principle #3Local quality

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 design enhances fuel flow capacity without increasing design costs, ensuring efficient fuel delivery to internal combustion engines by increasing the overall aperture for fuel discharge through the valve.

Implementation Method 1

a spring arranged between the plug and the inner surface of the closed end of the piston, the plug being shaped so that, when housed inside the axial discharge opening of the sleeve, the load of the spring is transmitted to the plug in a uniform manner around the axis A

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3698037B1Metering valve for a pump unit for feeding fuel to an internal combustion engine and pump unit comprising such a valve
Publication Date: 2021.12.29 ROBERT BOSCH GMBH
  • EP3698037B1 patent drawingFigure 1~2
  • EP3698037B1 patent drawingFigure 3~6

AI summary

A metering valve (7) for a pump unit (1) for feeding fuel from a tank (2) to an internal combustion engine (3); the metering valve comprising: a sleeve (27) having an axis (A) and provided with a first open end for receiving a thruster (21), a second opposite end provided with an opening (35) for axially discharging the fuel and at least one side opening (28) for feeding fuel; a plug-shaped piston (30) housed slidably along the axis (A) inside the sleeve (27), the piston (30) being provided with a closed end (31) having an outer surface in contact with the thruster (21), an open opposite end and at least one side opening (34); a plug (33) housed inside the discharge opening (35) of the sleeve (27) and provided with an axial opening (38); a spring (32) arranged between the plug (33) and the inner surface of the closed end (31) of the sleeve (27).