Motor Vehicle Door Lock Coupling Lever Guide Contour
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Solution Overview
Problem
Existing motor vehicle door locks face issues where the coupling lever fails to properly interact with the mass inertia element during a crash, leading to potential inadvertent opening of the locking mechanism due to minimal mechanical contact and potential contamination or corrosion, compromising safety features like side airbags.
Innovation Solution
The design features a guide contour on the mass inertia element and a contact contour on the coupling lever that exert forces tangentially to their respective axes, ensuring a smooth transition of the coupling lever from the 'engaged' to the 'disengaged' position during a crash, even with contamination or corrosion, through a rolling motion that prevents hooking and maintains functionality over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a journal and stop or arcuate contour are used for interaction between coupling lever and mass inertia element, then the coupling lever can be guided during crash, but manufacturing tolerances cause functional impairments via mutual hooking
Solution Approach 1:
The patent replaces the traditional journal-stop contact with a spherical contact element that interacts with a curved guide contour. The spherical geometry provides self-centering action and tolerance compensation, eliminating the mutual hooking problem caused by precise dimensional requirements of flat journal-stop interfaces. The curvature of both contact surfaces allows for smooth guidance during crash events while being insensitive to manufacturing variations.
2Device complexity
If minimal mechanical contact is provided between coupling lever and mass inertia element, then the structure is simplified, but contamination and corrosion lead to functional impairments over time
Solution Approach 1:
The patent introduces a spherical contact element as an intermediary between the coupling lever and mass inertia element. This spherical mediator provides optimal contact geometry that distributes loads and minimizes stress concentration points where contamination and corrosion would typically initiate failure. The spherical interface allows for easier self-cleaning action and maintains functional reliability over the vehicle's lifetime.
3Reliability
If the coupling lever transitions smoothly from engaged to disengaged position during crash, then safety is improved, but additional forces beyond torque are required
Solution Approach 1:
The patent utilizes the mass inertia element as a counterweight that remains substantially stationary during crash events due to its high moment of inertia. The spherical contact element on the coupling lever interacts with the guide contour of this mass counterweight, allowing smooth transition from engaged to disengaged position through torque alone. The mass element's resistance to acceleration provides the necessary counterbalancing effect without requiring additional actuating forces.
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 ensures a secure and reliable interaction between the coupling lever and mass inertia element, preventing inadvertent opening of the locking mechanism during crashes and maintaining operational integrity over the vehicle's lifespan by creating a large contact surface and transferring torques without additional forces, thus enhancing safety and reliability.
Implementation Method 1
a mass inertia element (10) which is rotatable about an additional axis (11), which is spaced apart from the axis (8) of the coupling lever (7), in order to guide the coupling lever (7), at least in the event of a crash
Implementation Method 2
the guide contour (14) and/or the contact contour (13) is configured so that a force which is exerted upon it runs essentially tangentially to the diameter of the associated axis
Data Source
AI summary
A motor vehicle door lock includes a locking mechanism having a rotary latch, a pawl, and an actuating lever mechanism having at least one coupling lever rotatable about an axis and a mass inertia element rotatable about an additional axis spaced apart from the axis of the coupling lever to guide the coupling lever, at least in the event of an accident. The coupling lever in its “engaged” position connects the actuating lever mechanism mechanically with the locking mechanism and in its “disengaged” position ensures that the actuating lever mechanism is locked and/or separated from the locking mechanism. The mass inertia element has a guide contour for the coupling lever that interacts with a contact contour of the coupling lever so that the guide contour and/or contact contour is configured so that a force exerted upon it runs essentially tangentially to the diameter of the associated axis.