Motor Vehicle Lock Pawl Axial Constraint Mechanism
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Solution Overview
Problem
Existing motor vehicle locks, particularly side door locks, face instability issues during high tearing forces in the vehicle transverse direction, leading to potential axial movement of the pawl and failure to maintain the locking mechanism's closing function, despite reinforcement measures.
Innovation Solution
The pawl is equipped with an extension that engages under a hook to limit axial movement, ensuring the pawl remains secured within the bearing opening, enhancing mechanical stability by integrating the hook as a deformed component of the lock plate through shaping processes, and optionally supported by a reinforcing plate spanning both axes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If reinforcement measures are taken to increase mechanical stability, then the lock can withstand higher forces, but the pawl may still move axially under extreme transverse loads
Solution Approach 1:
The locking mechanism is divided into functionally independent components: the hook for axial constraint, the extension for engagement, the bearing bolt for rotational support, and the thickened edge area for structural reinforcement. This segmentation allows each element to specialize in addressing specific failure modes, collectively achieving comprehensive stability under extreme loads.
Solution Approach 2:
The hook and extension are pre-configured in specific geometric relationships during manufacturing, creating a predetermined axial constraint system. This preliminary configuration ensures that when transverse forces are applied, the pawl is already positioned to engage the hook and prevent axial movement, rather than relying on reactive measures during failure.
2Strength
If the lock plate is made of solid metal to ensure mechanical stability, then safety is improved, but weight increases
Solution Approach 1:
Instead of uniformly reinforcing the entire lock plate, the invention applies material thickness increases only in the specific area of the bearing opening where high forces act on the bearing bolt. This localized thickening provides necessary strength at the critical stress point while maintaining lighter weight in non-critical areas of the lock plate.
Solution Approach 2:
The lock plate combines different material properties in a single structure: solid metal provides overall strength, while the thickened edge area provides localized reinforcement. The composite structure of varying thickness within the same material allows optimization of both weight and strength by placing material only where mechanically necessary.
3Reliability
If the pawl is constrained axially to prevent movement, then reliability is improved, but the device complexity increases
Solution Approach 1:
The hook is integrated as a deformed component of the lock plate itself rather than being a separate part, and the extension is formed as part of the pawl structure. This merging of components reduces the number of discrete parts and assembly steps while achieving the axial constraint function, thereby improving reliability without proportionally increasing device complexity.
Solution Approach 2:
The hook and extension form a self-contained axial constraint system that automatically engages and disengages based on the pawl's position. The geometric relationship between the hook and extension creates a self-regulating mechanism that prevents axial movement without requiring external control systems, sensors, or additional actuating components, thus maintaining simplicity.
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 significantly increases mechanical stability, allowing the lock to withstand forces exceeding 13.6 kN, up to 18 kN or more, ensuring the locking mechanism functions effectively during crashes by preventing axial movement of the pawl and reinforcing the lock's structural integrity.
Implementation Method 1
at least one thickened edge area with locally increased sheet thickness is created. The edge area produced and thickened in this way is generally located in the area of the bearing opening. This provides increased material thickness in this area, enabling it to absorb high forces acting on the bearing bolt
Implementation Method 2
The pawl is equipped with an extension that engages under a hook to limit axial movement, ensuring the pawl remains secured within the bearing opening
Implementation Method 3
at least the locking pawl is inserted into a bearing opening of the lock plate by means of a bearing bolt and is fixed therein
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a motor vehicle door lock, particularly a motor vehicle side door lock, provided with a locking plate (1) and a catch (2, 3) which is mounted on the locking plate (1) and which consists of a rotary latch (2) and a pawl (3). At least the pawl (3) is inserted into a bearing opening (8) of the locking plate (1) with the aid of a bearing pin (5) and fixed therein. According to the invention, the pawl (3) is equipped with an extension (6) which engages under a hook (9, 10, 11) limiting an axial movement of the pawl (3).