Fuel Injector Control Signal Timing to Reduce Armature Bouncing

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Solution Overview

Problem

The existing injector units for internal combustion engines face issues with armature bouncing due to the magnetic force striking a stop, leading to temporal variance in nozzle needle movement, increased fuel consumption, wear on components, and thermal challenges, which are not adequately addressed by prior art solutions.

Innovation Solution

The injector unit incorporates a control unit that reduces the electromagnet's control signal before the anchor element contacts the stop, interrupting the signal to minimize the magnetic force and prevent armature bouncing, allowing for precise control and reduced wear by ensuring the anchor element hits the stop at zero or low speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the electromagnet applies full magnetic force to lift the armature element, then the opening speed is improved, but armature rebound against the stop occurs causing temporal variance

Engineering Contradiction:
Improveopening speedVSAvoidtemporal variance
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The control signal is applied in a periodic manner: first activating the electromagnet to lift the armature element quickly, then deactivating it before the armature contacts the stop to prevent rebound. This periodic on-off action sequence resolves the contradiction by maintaining high opening speed while eliminating temporal variance through controlled interruption.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The control signal is deactivated in advance before the armature element reaches the stop, preventing the rebound condition from occurring. This preliminary deactivation eliminates the harmful effect while preserving the beneficial quick opening action that occurred earlier in the cycle.

Inventive Principle:
Principle #10Preliminary action

2Speed

If the electromagnet applies full magnetic force continuously, then the opening speed is improved, but wear on the armature and stop increases

Engineering Contradiction:
Improveopening speedVSAvoidcomponent wear
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The control signal is deactivated before the armature element contacts the stop, preventing rebound and the associated wear. This preliminary interruption of the magnetic force eliminates the harmful impact while maintaining the beneficial quick opening action.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The potential harmful rebound action is converted into a controlled deceleration phase by timing the signal deactivation. The armature naturally decelerates due to spring force and friction before contact, transforming what would be a harmful high-speed impact into a controlled, low-wear operation.

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

3Speed

If the electromagnet applies full magnetic force continuously, then the opening speed is improved, but thermal heat generation increases

Engineering Contradiction:
Improveopening speedVSAvoidthermal heat
Core Design Contradiction:
SpeedVSTemperature

Solution Approach 1:

The control signal is applied periodically rather than continuously - activated for the brief duration needed to lift the armature, then deactivated before contact with the stop. This periodic operation significantly reduces the total energy consumption and thermal heat generation while maintaining the required opening speed performance.

Inventive Principle:
Principle #19Periodic 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

This approach significantly reduces armature bouncing, enabling more precise injection quantity control, minimizing wear, and reducing thermal issues, thus improving the operational efficiency and longevity of the injector unit.

Implementation Method 1

an electromagnet (6, 7) that is designed to apply a magnetic force to the armature element (4) in order to lift the armature element (4) from the seat plate (2)

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 2

a spring element (5) that urges the armature element (4) toward the seat plate (2) in order to close the through-opening (3)

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP3921536B1Injector unit for the injection of fuel, and method for the operation of an injector unit of this type
Publication Date: 2024.04.03 LIEBHERR COMPONENTS DEGGENDORF GMBH
  • EP3921536B1 patent drawingFigure 1~2

AI summary

In accordance with the invention, the injector unit for the injection of fuel comprises a seat plate with a through opening which extends through the seat plate, an armature element which can be placed onto the seat plate, in order to close the through opening, a spring element which pushes the armature element in the direction of the seat plate, in order to close the through opening, an electromagnet which is designed to load the armature element with a force, in order to lift the armature element from the seat plate, and a stop for limiting a stroke of the armature element in a state in which it is lifted from the seat plate. The injector unit is characterized by a control unit which is designed to reduce an actuating signal of the electromagnet for lifting the armature element from the seat plate before the armature element makes contact with the stop for the first time after being lifted from the seat plate.