Motor Vehicle Door Lock U-Shaped Spring Composite Design

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Solution Overview

Problem

Existing motor vehicle door locks with uniform material design for control elements and springs suffer from long-term functional impairments due to material brittleness, leading to potential spring breakage and reduced reliability.

Innovation Solution

A motor vehicle door lock design featuring a U-shaped spring with distinct contour and fixing legs, where the spring is made of steel and the control element of plastic, ensuring long-lasting functionality by minimizing plastic-steel friction and allowing manual actuation between functional positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the control element and spring are made of the same material (plastic), then manufacturing and assembly are simplified, but long-term reliability deteriorates due to material brittleness and spring breakage

Engineering Contradiction:
Improvemanufacturing and assembly simplicityVSAvoidlong-term functional reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies composite materials by combining plastic for the control element and steel for the spring. This material differentiation allows the plastic control element to provide ease of manufacture and assembly, while the steel spring provides long-term reliability and resistance to brittleness. The spring is designed with a U-shape and made of steel, while the control element remains plastic, creating a composite structure that resolves the contradiction between manufacturing simplicity and long-term reliability.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If the spring is made of plastic to match the control element, then assembly costs are reduced, but functional reliability deteriorates over time due to brittleness

Engineering Contradiction:
Improveassembly costsVSAvoidfunctional reliability over time
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent uses composite materials with the control element made of plastic and the spring made of steel. This combination maintains cost-effectiveness while significantly improving functional reliability over time. The steel spring resists brittleness and material degradation that would occur with plastic, ensuring the door lock maintains its functionality throughout its service life.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by using different materials in different locations within the same assembly. The control element that requires ease of manufacture is made of plastic, while the spring that requires long-term reliability is made of steel. This localized material selection optimizes each component for its specific functional requirements while maintaining overall system reliability.

Inventive Principle:
Principle #3Local quality

3Device complexity

If a uniform material design is used for all components, then device complexity is reduced, but long-term operation reliability is compromised

Engineering Contradiction:
Improvematerial design complexityVSAvoidlong-term operation reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements composite materials with a plastic control element and a steel spring, creating a multi-material design that enhances long-term operation reliability. While this increases material design complexity slightly, it prevents the brittleness and failure issues associated with uniform plastic construction, ensuring reliable operation throughout the door lock's service life.

Inventive Principle:
Principle #40Composite materials

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 guarantees high functional reliability and long-lasting operation with reduced installation and assembly costs, maintaining flawless functionality over extended periods by using different materials for the spring and control element.

Implementation Method 1

a spring (9) made of different materials, in particular a spring (9) made of metal, in particular steel

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

maintaining flawless functionality over extended periods by using different materials for the spring and control element

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3580413B1Motor vehicle door lock
Publication Date: 2021.03.17 KIEKERT AG
  • EP3580413B1 patent drawingFigure 1
  • EP3580413B1 patent drawingFigure 2
  • EP3580413B1 patent drawingFigure 3

AI summary

The invention relates to a motor vehicle door lock, the basic construction of which is equipped with a locking mechanism and a control element (2) that can be moved back and forth between at least two functional positions. The control element is a child-proof lock element (2) or an emergency locking element for example. The control element (2) is equipped with at least one spring (9) which is made of a different material for assuming the two functional positions in a reversible manner in each case. According to the invention, the spring (9) is mostly U-shaped with two limbs (9a, 9b). One limb (9a) is designed as a contoured limb (9a) and interacts with a stationary contour (11) for assuming the two functional positions. Conversely, the other limb (9b) is used as a fixing limb (9b) for securing the spring (9) to the control element (2).