Magnet Assembly for Injection Valve Dynamics

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Solution Overview

Problem

Existing magnet assemblies for fuel injection valves face challenges in achieving rapid dynamics due to high spring forces requiring high magnetic forces and increased voltage, which negatively impact both opening and closing behaviors.

Innovation Solution

A magnet assembly incorporating a ring-shaped permanent magnet integrated into the magnetic core, where the permanent magnet's basic magnetic flux either complements or opposes the coil's magnetic flux to adjust the acting force on the armature, allowing for reduced energization during opening and enhanced closing dynamics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If high spring force is used to achieve rapid closing, then closing speed is improved, but opening dynamics deteriorate due to high magnetic force requirements

Engineering Contradiction:
Improveclosing speedVSAvoidmagnetic force requirement
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The permanent magnet is pre-installed in the magnetic core to generate a basic magnetic flux before the coil is energized. This preliminary magnetic field reduces the additional magnetic force needed from the coil during opening, thereby lowering energy consumption while maintaining rapid closing performance through the spring force.

Inventive Principle:
Principle #10Preliminary action

2Speed

If increased voltage is applied to improve opening dynamics, then opening speed is improved, but closing behavior deteriorates and energy consumption increases

Engineering Contradiction:
Improveopening speedVSAvoidvoltage consumption
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The permanent magnet provides a preliminary magnetic flux that reduces the voltage needed from the coil to achieve rapid opening. This prevents excessive voltage application and associated energy losses while maintaining fast opening dynamics.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The permanent magnet changes the magnetic flux parameter in the circuit, providing a baseline flux that reduces the additional flux required from the coil. This parameter change enables faster opening at lower voltages and prevents energy-wasting over-energization during the holding phase.

Inventive Principle:
Principle #35Parameter changes

3Force

If high magnetic force is generated to overcome high spring force, then opening capability is improved, but closing bounce increases

Engineering Contradiction:
Improvemagnetic forceVSAvoidclosing bounce
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The permanent magnet's basic magnetic flux is established before coil energization, providing a controlled magnetic force that opens the valve without excessive force. This prevents the high closing bounce that would result from abruptly cutting off a much stronger coil-generated magnetic field.

Inventive Principle:
Principle #10Preliminary 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 configuration improves the dynamics of the injection valve by enabling rapid opening and closing with reduced voltage requirements, minimizing closing bounces and maintaining efficient operation.

Implementation Method 1

the permanent magnet influences the polarity of the magnet assembly. This is the case when the basic magnetic flux generated by the permanent magnet increases or decreases the magnetic force when the magnet coil is energized.

Methodology Applied
Scientific EffectMagnetic flux: Magnetic Field

Implementation Method 2

a magnet coil which can be energized in dependence on the polarity of the permanent magnet in the same or in opposite direction with respect to the polarity of the permanent magnet

Methodology Applied
Scientific EffectElectromagnetic interaction: Electromagnetic Induction

Implementation Method 3

When the magnetic coil is energized, a magnetic force is generated which causes the armature to be lifted against the spring force of the closing spring

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP2392815B1Magnet assembly and injection valve with same
Publication Date: 2014.11.12 ROBERT BOSCH GMBH
  • EP2392815B1 patent drawingFigure 1
  • EP2392815B1 patent drawingFigure 2
  • EP2392815B1 patent drawingFigure 3

AI summary

The component has a magnetic core (1) provided for direct or indirect control of an injection valve member, and a recess (2) arranged for receiving the magnetic core wound with a solenoid coil (3). A lifting-motion armature (4) interacts with the coil and an annular shaped permanent magnet (5). The magnet integrates into an outer pole (6), inner pole (7) or bottom (8) of the magnetic core or into the armature and produces the magnetic flux that energizes the coil and amplifies or attenuates magnetic force acting on the armature.