Piezo Injector Electrical Connection Strain Relief

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Solution Overview

Problem

Existing injectors for internal combustion engines with piezo-actuated control units face challenges in providing a reliable and robust electrical connection between the piezo-actuated control unit and the connecting plug, which is susceptible to damage and complex to produce for series production.

Innovation Solution

A contact element with integrated conductor tracks in an insulating body, connected to the terminals of the control unit and connector plug, featuring an elastic device for bracing and strain relief, ensuring mechanical stability and protection against vibrations, and allowing for thermal expansion and axial movements without additional stress on connection points.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If insulated wires with silicone casting are used for electrical connection, then the connection is protected against vibrations, but the construction becomes complex and susceptible to damage

Engineering Contradiction:
Improveprotection against vibrationsVSAvoidconstruction complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the electrical connection function with the insulating body into a single integrated component. The contact element with conductor tracks embedded in the insulating body eliminates the need for separate insulated wires and silicone casting, reducing construction complexity while maintaining vibration protection through the integrated structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The contact element acts as an intermediary component between the piezo-actuator control unit and the connecting plug. It provides a robust electrical connection through its integrated conductor tracks and insulating body, mediating the electrical connection while protecting against vibrations without requiring complex assembly of multiple separate components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the insulating body is rigidly fixed at both ends, then mechanical stability is improved, but thermal expansion and axial movements cause additional stress on connection points

Engineering Contradiction:
Improvemechanical stabilityVSAvoidstress on connection points
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The patent applies a dynamic bracing concept where the insulating body is braced with an axial force at one end while the other end remains free to move. This dynamic arrangement allows the contact element to accommodate thermal expansion and axial movements without transmitting additional stress to the connection points, while still providing sufficient mechanical stability through the axial bracing.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the boundary conditions of the insulating body from rigid fixation at both ends to bracing with axial force at one end and free movement at the other. This parameter change allows the system to accommodate thermal and mechanical variations while maintaining mechanical stability where needed.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the electrical connection is designed for simplicity, then assembly efficiency is improved, but reliability against vibrations and thermal changes deteriorates

Engineering Contradiction:
Improveassembly efficiencyVSAvoidresistance to vibrations and thermal changes
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The integrated contact element with embedded conductor tracks and insulating body simplifies assembly by eliminating multiple separate components (wires, connectors, insulation materials), while the bracing concept ensures reliability against vibrations and thermal changes through proper mechanical support and stress relief.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The contact element design allows for self-aligning and self-accommodating features where the braced insulating body automatically adjusts to thermal expansion and vibration conditions, maintaining reliability without requiring complex adjustment mechanisms or additional assembly steps.

Inventive Principle:
Principle #25Self-service

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 solution provides a simple, robust, and durable electrical connection that is resistant to vibrations and thermal changes, ensuring a stable and reliable power supply to the piezoactuator while allowing for necessary movements, thus enhancing the injector's durability and assembly efficiency.

Implementation Method 1

the contact element has an elastic device for bracing the insulating body resting on the control unit or the connecting plug with the control unit or the connecting plug

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3060790B1Injector
Publication Date: 2021.05.26 VITESCO TECHNOLOGIES GMBH
  • EP3060790B1 patent drawingFigure 1~2

AI summary

The invention describes an injector of injection system of an internal combustion engine. The injector has an injector housing, a piezo-actuator control unit, a connecting plug on the head of the injector housing, and an electrical connection between the control unit and the connecting plug within the injector housing. The electrical connection comprises a contact element with an elastic device for bracing the contact element against the control unit or the connecting plug. One end of the contact element bears against the control unit or the connecting plug, whereas the other end is arranged with a corresponding spacing. In this way, movements of the control unit and thermal expansions can be compensated.