Motor Vehicle Door Lock Actuation Force Reduction

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Solution Overview

Problem

Existing motor vehicle locks require significant force to transition between safety unit positions, particularly in purely mechanical systems, limiting the ease of actuation and efficiency.

Innovation Solution

A motor vehicle lock design featuring a spring unit and cam that define two positions with a relative movement comparable to an unstable equilibrium, reducing operational forces required for position change, where the spring unit is connected to an actuation nut and can be made from plastic, allowing for easy implementation and low-force operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a purely mechanical assessment is used in the safety unit, then the structural simplicity is improved, but the force required for actuation increases significantly

Engineering Contradiction:
Improvestructural simplicityVSAvoidactuation force
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

A cam element is introduced as an intermediary between the adjustment element and the clutch element. The cam profile transforms the actuation motion into a mechanical advantage, enabling the purely mechanical safety unit to operate with reduced force requirements while maintaining structural simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The cam element creates a dynamic mechanical advantage during actuation. By designing the cam profile with specific geometric characteristics, the system achieves variable force transmission during the actuation process, reducing the peak force required compared to a direct mechanical connection.

Inventive Principle:
Principle #15Dynamics

2Reliability

If multiple levers are moved in the safety unit, then the functional reliability is improved, but the force required for position transition increases

Engineering Contradiction:
Improvefunctional reliabilityVSAvoidposition transition force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

Multiple lever movements are merged into a single coordinated motion through the cam mechanism. The cam profile synchronizes the actuation of different components, allowing them to move together in a coordinated fashion rather than requiring separate high-force actuations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cam element utilizes curved surface geometry to transform linear actuation motion into rotational or complex multi-axis movements. This curvature-based mechanism allows multiple levers to be actuated simultaneously with reduced force by distributing the mechanical work across the curved contact surface.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Device complexity

If a direct mechanical connection is used between the adjustment element and clutch element, then the structural complexity is reduced, but the ease of operation deteriorates

Engineering Contradiction:
Improvestructural complexityVSAvoidease of actuation
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The cam element serves as a simple intermediary component that significantly improves ease of operation. It can be implemented as a basic geometric feature on existing components rather than a complex separate mechanism, maintaining low structural complexity while providing substantial operational improvement.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The cam profile changes the mechanical parameters of force and motion during actuation. By carefully designing the cam geometry, the system transforms a difficult high-force operation into an easier low-force operation while maintaining the same functional outcome, all with a simple geometric modification.

Inventive Principle:
Principle #35Parameter changes

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

Enables easy manual or motorized switching between safety unit positions with minimal operational force, enhancing the power conditions and usability of the lock.

Implementation Method 1

a relative movement between the cam and the spring unit or between the cam including the spring unit and a contour comparable to a unstable equilibrium for the change between both positions ensures

Methodology Applied
Scientific EffectUnstable equilibrium: Metastability

Implementation Method 2

whereby the spring unit, which interact with the adjustment element, is intended to take the two positions

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3822435B1Motor vehicle lock, in particular motor vehicle door lock
Publication Date: 2022.12.28 KIEKERT AG
  • EP3822435B1 patent drawingFigure 1
  • EP3822435B1 patent drawingFigure 2~3
  • EP3822435B1 patent drawingFigure 4~6

AI summary

The invention relates to a motor vehicle lock, in particular a motor vehicle door lock, which is equipped with a locking mechanism (1, 2) consisting essentially of a rotary latch (1) and a pawl (2). Furthermore, an actuating lever chain (3, 4) for actuating the locking mechanism (1, 2) and a locking unit (5, 6) are provided. In its "on" position, the locking unit (5, 6) disables the actuating lever chain (3, 4). In its "off" position, the locking unit (5, 6) engages the actuating lever chain (3, 4). The locking unit (5, 6) has a mechanically and/or motor-driven actuating element (5). A spring unit (6), which interacts directly or indirectly with the actuating element (5), is also provided to assume the two positions. According to the invention, the spring unit (6), together with a cam (7), defines the two positions of the locking unit (5, 6).This occurs in a manner comparable to an unstable equilibrium and causes the change between the two positions.