Motor Vehicle Door Rotary Latch Vibration Stability

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Solution Overview

Problem

Existing motor vehicle door locking mechanisms are prone to opening due to vibration forces, leading to noise and insecurity when closing, as the pawl can be displaced from the rotary latch, compromising the door's secure closure.

Innovation Solution

The locking mechanism features a rotary latch and pawl mechanism where the force from the rotary latch generates a torque that reinforces the blocking between the pawl and rotary latch, with the door seal providing additional stability, and a locking lever that can be manually or motor-driven to disengage the pawl, allowing for a rolling movement that reduces noise during opening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the pawl is arranged to be loaded in the opening direction by vibration forces, then the door can open easily, but the door becomes insecure and generates noise during closing

Engineering Contradiction:
Improveease of openingVSAvoidsecurity of closed position
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent inverts the loading direction of the pawl mechanism. Instead of loading the pawl in the opening direction (prior art), the patent loads the pawl in the closing direction through the rotary latch. This inversion ensures that vibration forces cannot displace the pawl in the opening direction, preventing unwanted door opening while maintaining secure closure. The pawl is now stabilized against vibration-induced displacement by the closing-direction load from the rotary latch.

Inventive Principle:
Principle #13The other way round (Inversion)

2Force

If the pawl is loaded in the opening direction, then the door can open with less force, but the pawl can be displaced by vibrations causing the door to open unintentionally

Engineering Contradiction:
Improveopening forceVSAvoidvibration displacement
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The patent applies a counteracting force principle by loading the pawl in the closing direction through the rotary latch. This closing-direction load acts as a counterweight to vibration forces that would otherwise displace the pawl in the opening direction. The spring-loaded rotary latch continuously applies this stabilizing force, preventing vibration-induced pawl displacement and unintentional door opening while still allowing controlled opening when needed.

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

3Ease of operation

If the pawl and rotary latch are arranged to generate torque in the opening direction, then the door opens smoothly, but the positive connection is compromised under vibration

Engineering Contradiction:
Improvesmooth openingVSAvoidpositive connection stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent inverts the torque generation direction. Instead of arranging the pawl and rotary latch to generate torque in the opening direction (prior art), the patent configures them to generate torque in the closing direction. This inversion stabilizes the positive connection between the pawl and rotary latch under vibration conditions, as the closing-direction torque reinforces their engagement rather than working against it, while still permitting controlled opening through the lifting magnet mechanism.

Inventive Principle:
Principle #13The other way round (Inversion)

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 mechanism ensures the door remains securely closed under vibrations and reduces noise during opening by maintaining a stable connection between the pawl and rotary latch, preventing unwanted opening and minimizing pulse-like noise.

Implementation Method 1

the force of the rotary latch generates a torque that reinforces the blocking between the pawl and the rotary latch

Methodology Applied
Scientific EffectTorque: Torque

Implementation Method 2

A spring loads the rotary latch in the opening direction

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

Both the pawl spring and the door seal exert pressure on the pawl via the striker and the rotary latch

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP2492423B1Barrier with opening trends
Publication Date: 2018.12.26 BROSE SCHLIESSSYSTEME GMBH & CO KG
  • EP2492423B1 patent drawingFigure 1
  • EP2492423B1 patent drawingFigure 2
  • EP2492423B1 patent drawingFigure 3

AI summary

The mechanism (6) has a rotary latch (1) pivotally connected with a closing bracket in a closed motor vehicle door. A locking pawl (3) blocks the rotary latch in a pre-latching position or main latching position in the closed motor vehicle door. An assembly consists of an intermediate lever (4), and the locking pawl is mounted on the intermediate lever. The rotary latch loads the locking pawl in the closed motor vehicle door along closing direction, and the assembly of the intermediate lever and locking pawl is loaded along opening direction.