Motor Vehicle Tailgate Lock Pawl Blocking Contour

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Solution Overview

Problem

Existing motor vehicle locks, particularly tailgate locks, face issues with the pawl unintentionally falling back into the rotary latch during the opening process, leading to unreliable functionality and the need for repeated operator intervention.

Innovation Solution

The driven pulley is equipped with a blocking contour that interacts with the pawl to prevent it from falling back into the rotary latch, utilizing an existing plastic output pulley and a spring for additional security, ensuring the pawl remains in its open position and is detected accurately by a sensor unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a motorized opening drive is used to open the lock remotely, then the convenience of operation is improved, but the reliability deteriorates because the pawl can unintentionally fall back into the rotary latch during the opening process

Engineering Contradiction:
Improveremote opening capabilityVSAvoidfunctional reliability of opening process
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The blocking contour on the driven pulley proactively prevents the pawl from falling back into the rotary latch by creating a mechanical barrier during the opening process. This preliminary protective measure eliminates the need for repeated operator intervention and ensures reliable remote opening operation.

Inventive Principle:
Principle #9Preliminary anti-action

2Reliability

If a blocking contour is added to the driven pulley to prevent pawl re-engagement, then the reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvefunctional reliability of opening processVSAvoidstructural complexity of driven pulley
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The blocking contour is integrated directly into the driven pulley structure, merging the blocking function with the existing drive mechanism. This approach avoids adding separate blocking components and minimizes structural complexity while achieving the reliability improvement.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The driven pulley is designed to serve multiple functions: transmitting motor torque to open the pawl and simultaneously providing the blocking contour to prevent accidental re-engagement. This multi-functionality reduces the need for additional dedicated components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If the pawl is lifted from engagement with the rotary latch during opening, then the opening function is achieved, but the risk of accidental re-engagement increases

Engineering Contradiction:
Improveopening speedVSAvoidrisk of accidental pawl re-engagement
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The blocking contour is positioned to act preventively during the pawl's opening trajectory, creating a mechanical barrier that stops the pawl before it can accidentally re-engage with the rotary latch. This eliminates the harmful effect while maintaining efficient opening operation.

Inventive Principle:
Principle #9Preliminary anti-action

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 solution provides a functionally reliable and secure opening mechanism with reduced design complexity, preventing accidental pawl re-engagement and ensuring the motor vehicle lock is properly closed, thus enhancing operational convenience and safety.

Implementation Method 1

the driven pulley has a spring that interacts with at least one ramp stop to secure the end position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3812541B1Motor vehicle lock, in particular lock of a vehicle boot lid
Publication Date: 2023.12.20 KIEKERT AG
  • EP3812541B1 patent drawingFigure 1
  • EP3812541B1 patent drawingFigure 2
  • EP3812541B1 patent drawingFigure 3A

AI summary

The invention relates to a motor vehicle lock, in particular a motor vehicle door lock and preferably a motor vehicle tailgate lock. In its basic design, this lock comprises a locking mechanism (1, 2) consisting essentially of a rotary latch (1) and a pawl (2). Furthermore, a motorized opening drive (7, 8, 9, 10, 11) for the pawl (2) is provided, wherein the motorized opening drive (7, 8, 9, 10, 11) has a drive screw (8) for the rotary actuation of a drive disk (9, 10, 11). The drive disk (9, 10, 11) also acts indirectly or directly on the pawl (2). According to the invention, the output disk (9, 10, 11) has an additional blocking contour (13) that interacts with the pawl (2), which prevents the pawl (2) from falling into the rotary latch (1) at least during the opening process of the locking mechanism (1, 2).