Solenoid Valve Injector Opening Time Determination

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Solution Overview

Problem

Solenoid valve injectors in internal combustion engines experience delays in opening and closing due to tolerances, leading to uneven fuel distribution, which existing methods fail to accurately determine and account for, affecting the precision of fuel injection.

Innovation Solution

A method to determine the opening time of a solenoid valve injector by calculating the armature impact time and opening delay time, using voltage curve analysis and models to account for electromagnetic and biasing forces, allowing for precise determination of the opening time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If solenoid valve injectors are electrically controlled to enable precise fuel injection, then fuel injection precision is improved, but opening and closing delays occur due to tolerances causing uneven fuel distribution

Engineering Contradiction:
Improvefuel injection precisionVSAvoidfuel distribution uniformity
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by determining the armature impact time and opening delay time in advance through voltage curve analysis. The control unit calculates these parameters before the actual injection event, allowing the system to compensate for tolerances and predict the actual opening time, thereby ensuring both precision and uniformity in fuel distribution.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by monitoring the voltage curve of the solenoid valve during actuation and using this information to determine the armature impact time and opening delay time. This feedback mechanism allows the control unit to adjust and compensate for variations in opening and closing delays, ensuring uniform fuel distribution while maintaining precise injection control.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If existing methods are used to determine opening time, then device complexity is reduced, but measurement precision of opening time is insufficient leading to inaccurate fuel injection timing

Engineering Contradiction:
Improveopening time determination accuracyVSAvoidmethod complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical measurement methods with electrical field-based measurement. Instead of using complex mechanical sensors or physical measurement devices, the system analyzes the voltage curve of the solenoid valve's electrical field during actuation. This substitution achieves high measurement precision for opening time while keeping the device complexity low, as the voltage curve analysis can be performed using existing control unit capabilities.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If voltage curve analysis is performed to determine armature impact time, then opening time measurement precision is improved, but computational requirements and processing time increase

Engineering Contradiction:
Improvearmature impact time accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies partial action by focusing the voltage curve analysis on specific critical portions of the curve that contain the armature impact time information. Instead of analyzing the entire voltage curve in detail, the method identifies and processes only the relevant segments, achieving high measurement precision while minimizing computational requirements and processing time.

Inventive Principle:
Principle #16Partial or excessive action

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

Enables precise and efficient determination of the opening time of solenoid valve injectors, improving fuel distribution uniformity and reducing operational tolerances.

Implementation Method 1

The injector has a coil for generating a magnetic field, so that the coil can be used as an electromagnet

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

During this opening phase, the magnetic force exceeds the biasing force of the biasing element. Thus, during the opening phase, the armature mounted on the valve needle can be moved by the magnetic force

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnet

Implementation Method 3

the valve needle is pressed into a valve seat by a biasing element, e.g. a spring

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP4237675B1Method for determining an opening time of an injector having a solenoid valve, computer program, control apparatus, internal combustion engine and motor vehicle
Publication Date: 2024.12.11 VOLKSWAGEN AG
  • EP4237675B1 patent drawingFigure 1a~1b
  • EP4237675B1 patent drawingFigure 2
  • EP4237675B1 patent drawingFigure 3

AI summary

The invention relates to a method for determining an opening time of an injector having a solenoid valve. The method comprises: determining a time of contact of the armature, at which an armature of a solenoid valve comes into contact with a valve needle of the solenoid valve; determining an opening delay time of the injector, which corresponds to a time span between the time of contact of the armature and an opening time of the solenoid valve; and determining an opening time of the injector based on the time of contact of the armature and the opening delay time.