Motor Vehicle Door Lock Pawl Overcomes Self-Locking
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Solution Overview
Problem
Motor vehicle locks with double ratchet mechanisms face issues with increased self-locking forces due to years of use and environmental conditions, making it difficult to open the locking mechanism with sufficient force.
Innovation Solution
A dual-function pawl that secures the comfort pawl in the closed position and actively pushes it open during the opening process, utilizing a latching contour for securing and an opening contour for actuation, allowing the mechanism to overcome self-locking forces without additional springs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the comfort pawl is secured by the pawl in the closed position, then the locking mechanism maintains reliability, but increased self-locking forces develop over time due to deposits such as dust or dirt
Solution Approach 1:
The opening contour is designed to enable preliminary action by the pawl on the comfort pawl before the comfort pawl becomes stuck. The pawl acts on the actuating arm with a large translation at its radially outer end during the opening process, providing sufficient force to overcome self-locking forces before they fully develop, allowing the comfort pawl to be pushed in the opening direction proactively rather than reactively.
2Reliability
If additional springs are added to overcome self-locking forces, then the opening reliability improves, but the device complexity increases
Solution Approach 1:
The pawl is designed with multi-functionality to perform both the traditional function of securing the comfort pawl in the closed position and the additional function of actively pushing the comfort pawl in the opening direction during the opening process. This is achieved through the dual-contour design where the pawl interacts with the latching contour for securing and the opening contour for actuation, eliminating the need for separate spring mechanisms.
Solution Approach 2:
The opening contour is merged with the actuating arm structure, integrating the opening function directly into the existing pawl mechanism. The intermediate space between the actuating arm and stop arm is utilized as part of the opening contour, combining multiple functions into a single integrated structure rather than adding separate components.
3Force
If the pawl acts on the actuating arm with a large translation at its radially outer end, then the opening force increases, but the manufacturing precision requirements increase
Solution Approach 1:
The opening contour is designed in another dimension by utilizing the radial dimension of the actuating arm. The pawl acts on the actuating arm at its radially outer end, leveraging the radial distance from the rotation axis to create a large translation effect. This dimensional approach allows force multiplication through lever arm geometry rather than requiring precise linear positioning.
Data Source
Figure 1
Figure 2A~2D
Figure 3A~3B
AI summary
The invention relates to a motor vehicle lock, in particular motor vehicle door lock, which is designed in its basic structure with a locking mechanism having a rotary latch (1), a comfort catch (2) and a pawl (3). At least in the closed position of the locking mechanism (1, 2, 3), the pawl (3) latches the comfort catch (2) engaged in the rotary latch (1). According to the invention, the pawl (3) additionally urges the comfort catch (2) in the opening direction during at least one opening operation of the locking mechanism.