Motor Vehicle Door Lock Crash Unit Inertia Lever

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Solution Overview

Problem

Existing motor vehicle locks face challenges in maintaining functionality and reliability during crashes due to unintentional opening caused by deceleration forces, which can be complex and costly to address.

Innovation Solution

A simplified motor vehicle lock design where the clutch lever is part of both the crash unit and actuating lever system, remaining locked during crashes due to inertia, ensuring the locking mechanism remains closed, and transitioning to an unlocked position only during normal operation through a spring-loaded mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a crash unit with a locking element is designed to be variable in shape to prevent unintentional opening during crashes, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvefunctional reliabilityVSAvoidconstruction complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking element is designed to change its shape dynamically based on the operational state. In its normal form, the locking element is engaged by the actuating lever mechanism without any function. In the event of a crash, the locking element transforms into a locking form that corresponds to rendering the actuating lever mechanism and/or locking mechanism ineffective. This dynamic transformation allows the same component to serve multiple functions without requiring separate structures for each state.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The locking element serves multiple functions: in its normal form, it is engaged by the actuating lever mechanism for normal operation, and in its locking form, it renders the actuating lever mechanism and locking mechanism ineffective during crashes. By making the locking element variable in shape and multi-functional, the patent eliminates the need for separate crash prevention mechanisms, thereby improving reliability while controlling complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If the clutch lever is designed to remain locked during crashes using inertia, then reliability is improved, but the mechanism requires additional control components

Engineering Contradiction:
Improvefunctional reliabilityVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The clutch lever is designed to automatically remain locked during crashes by utilizing its own inertia. The control lever is set up to control the clutch lever, and during normal operation, the clutch lever moves to its unlocked position. However, during crashes with deceleration forces, the inertia of the clutch lever and control lever ensures that the clutch lever remains locked, automatically preventing unintentional opening without requiring additional active control systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The spring is configured to counteract the inertial forces acting on the control lever during crashes. The spring acts on the control lever to maintain the clutch lever in its locked position during deceleration events, effectively using elastic force to balance the inertial effect and ensure reliable locking during crashes.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

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 design enhances functional reliability and cost-effectiveness by maintaining the locked state of the actuating lever mechanism, preventing unintentional openings during crashes while allowing normal operation unlocking, thus ensuring the vehicle remains securely locked during accidents.

Implementation Method 1

the control lever and an actuating lever of the actuating lever mechanism are coupled to each other by means of the spring... the control lever, due to its inertia, retains its position

Methodology Applied
Scientific EffectInertia: Inertia

Implementation Method 2

the crash unit is equipped with at least one spring which acts on a lever

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP4041971B1Motor vehicle lock, in particular a motor vehicle door lock
Publication Date: 2023.07.26 KIEKERT AG
  • EP4041971B1 patent drawingFigure 1A
  • EP4041971B1 patent drawingFigure 1B
  • EP4041971B1 patent drawingFigure 1C

AI summary

The present invention relates to a motor vehicle lock and in particular a motor vehicle door lock, which is equipped with a locking mechanism (1, 2) substantially comprising a catch (1) and pawl (2), and which is also equipped with an actuating lever mechanism (3, 4, 5, 7) for releasing the locking mechanism (1, 2) and with a crash unit (3, 7, 9, 10, 11). The crash unit deactivates the actuating lever mechanism (3, 4, 5, 7) and/or the locking mechanism (1, 2) at least in the event of deceleration forces having a predefined magnitude and direction, for example in the event of an accident (crash). For this purpose, the crash unit (3, 7, 9, 10, 11) is equipped with at least one spring (11) which acts on a lever (9). According to the invention, the lever (9) is designed as a control lever (9) of the crash unit (3, 7, 9, 10, 11), which control lever is designed to control a coupling lever (7) of the actuating lever mechanism (3, 4, 5, 7). The coupling lever (7) is continuously in its "locked" position and transitions into its "unlocked" position during normal operation only by means of the control lever (9) that is thus moved together with the actuating lever mechanism (3, 4, 5, 7).