Motor Vehicle Door Latch Retaining Element for Post-Accident Access
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Solution Overview
Problem
Motor vehicle door latches often become jammed or deformed during accidents, preventing the door from being opened by emergency services due to deformities in the door panel, which requires specialized tools and delays life-saving treatment.
Innovation Solution
A mechanical retaining element made of high-strength steel, integrated with the latch plate, maintains the inlet opening's size and shape, acting as a stop to prevent deformities from reaching the latch holder, ensuring the door can still be opened even after accidents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the motor vehicle door is designed with standard materials and structure, then manufacturing cost and complexity are kept low, but the door panel deforms during accidents causing the latch to jam
Solution Approach 1:
The door latch system is segmented into distinct functional components: the latch holder mounted on the door panel, the latch mechanism in the door frame, and the retaining element as a separate protective component. This segmentation allows the retaining element to independently prevent deformities from reaching the critical inlet opening, ensuring latch functionality even when other parts deform during accidents.
Solution Approach 2:
The retaining element is pre-positioned to protrude into the inlet opening before any accident occurs. This preliminary positioning creates a mechanical barrier that prevents deformities from the door panel from reaching the latch holder during lateral or offset impacts, ensuring the inlet opening remains accessible for emergency door opening.
2Strength
If high-strength materials are used for the retaining element, then resistance to accident-induced deformities is improved, but manufacturing cost increases
Solution Approach 1:
Instead of strengthening the entire door latch system or door panel, high-strength material is applied locally only to the retaining element where it is most needed to prevent deformities from reaching the inlet opening. This localized application of high-strength material minimizes manufacturing costs while maximizing protection where it critically matters for post-accident door opening.
Solution Approach 2:
The door latch system employs a composite material strategy where the retaining element is made from high-strength steel (yield strength >350 N/mm², preferably >500 N/mm²) while other components can use standard materials. This composite approach allows the critical retaining element to resist accident forces while keeping overall manufacturing costs reasonable by not over-engineering the entire system.
3Reliability
If the retaining element protrudes into the inlet opening, then prevention of deformity is improved, but the opening area is reduced
Solution Approach 1:
The retaining element acts as an intermediary barrier between the door panel and the latch holder. It protrudes into the inlet opening just enough to intercept and prevent deformities from reaching the critical latch components, while its strategic positioning and dimensions are optimized to maintain sufficient opening area for the latch holder to engage and disengage during normal operation and emergency opening.
Data Source
AI summary
The invention relates to a motor vehicle door locking system, comprising a motor vehicle door lock (1) on a motor vehicle door (2) and a lock retainer (3), interacting therewith, on a motor vehicle body (4), or vice versa, according to patent application DE 10 2014 007 119.7, characterized in that a hold-back element (5) is provided which keeps clear an inlet opening (6) for the lock retainer (3) in the motor vehicle door lock (1) even in the event of deformations of the motor vehicle door (2) caused by an accident, wherein the hold-back element (5) keeps the opening clear on account of a shaping of the hold-back element.