Electromagnetic Switching Valve Noise Reduction via Plastic Disc

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Solution Overview

Problem

High-pressure fuel pumps in internal combustion engines generate noise due to the contact between moving parts and limitations in the electromagnetic switching valve, leading to noise emissions that are not effectively minimized by existing solutions.

Innovation Solution

An electromagnetic switching valve design featuring a plastic disc with a recessed surface that decouples the armature and pole piece components, absorbing the impact and reducing noise transmission, combined with a spring arrangement that supports the armature and pole piece for efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the armature directly contacts the pole piece to ensure reliable switching, then the switching reliability is improved, but the noise emission increases due to impulse radiation

Engineering Contradiction:
Improveswitching reliabilityVSAvoidnoise emission
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

A plastic disc is introduced as an intermediary element between the armature and pole piece. The disc has a recessed contact surface that receives the armature impact, preventing direct metal-to-metal contact. This intermediary absorbs the switching impulse and prevents its radiation as noise, while still ensuring reliable mechanical coupling for actuation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The plastic disc with its recessed surface is pre-positioned between the armature and pole piece to cushion the upcoming impact. The recess geometry is designed to absorb the kinetic energy of the armature before it reaches the pole piece, thereby preventing the generation of harmful impulses and noise emissions during the switching operation.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Productivity

If the spring force is increased to improve valve closure speed, then the productivity is improved, but the impulse force on the pole piece increases, worsening the noise emission

Engineering Contradiction:
Improvevalve closure speedVSAvoidnoise emission
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The plastic disc serves as a mediator that decouples the spring force transmission from the pole piece. While the spring can be optimized for fast valve closure, the disc absorbs the resulting impulse forces, preventing their direct transmission to the pole piece and subsequent radiation as noise.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The recessed surface of the plastic disc provides beforehand cushioning for the spring-driven armature impact. This allows the spring force to be increased for faster valve closure without proportionally increasing the impulse force on the pole piece, as the disc absorbs the excess energy.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Productivity

If the electromagnetic actuator force is increased to improve switching speed, then the productivity is improved, but the impulse generated upon contact increases, worsening the noise emission

Engineering Contradiction:
Improveswitching speedVSAvoidnoise emission
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The plastic disc acts as an intermediary that allows the electromagnetic actuator to generate higher forces for faster switching. The disc's recessed surface absorbs the impulse from the armature, preventing direct transmission to the pole piece and eliminating the noise penalty associated with high-speed actuation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The plastic disc with its recessed geometry provides beforehand cushioning that enables the electromagnetic actuator to operate at higher forces and speeds. The cushioning effect absorbs the impulse energy, allowing fast switching without the harmful noise emissions that would result from direct high-force contact.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

The design significantly reduces noise emissions by dampening the impulse during operation, minimizing sound radiation and enhancing the overall performance of the fuel injection system.

Implementation Method 1

the plastic disc can metallically decouple the armature and pole piece components from each other. The impulse generated when the armature strikes the pole piece is dampened.

Methodology Applied
Scientific EffectImpact absorption: Damping

Implementation Method 2

a spring with a spring force acting on the closing element to bias the closing element into an open or closed position

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

an actuator section for moving the closing element with an actuator force opposing the spring force

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnet

Data Source

PatentEP3346122B1Electromagnetic switching valve and high-pressure fuel pump
Publication Date: 2019.07.17 VITESCO TECHNOLOGIES GMBH
  • EP3346122B1 patent drawingFigure 1
  • EP3346122B1 patent drawingFigure 2~3
  • EP3346122B1 patent drawingFigure 4~5

AI summary

The invention relates to an electromagnetic switching valve (26) with a pole piece (52) and an armature (50), wherein the armature (50) and the pole piece (52) move towards each other during operation with an armature approach surface (56) and a pole piece approach surface (58), wherein a recess (60) is provided in the pole piece approach surface (58) in which a plastic disc (62) is attached, the disc surface (64) of which is arranged offset from the pole piece approach surface (58). This is intended to dampen sound radiation. The invention further relates to a high-pressure fuel pump (20) which has such an electromagnetic switching valve (26).