Closure Latch Dual-Drive Gearset for High Seal Loads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power-operated vehicle door latch mechanisms require motors with excessive output force to overcome high seal loads, leading to increased size, weight, and cost, and fail to maintain functionality during crash conditions.
Innovation Solution
A power latch assembly with a multistage gear reduction mechanism that includes two power takeoffs, one for normal conditions and another for high seal loads, utilizing different gear reductions to optimize motor size and force, and incorporates a mechanical feature to prevent inadvertent unlatching during crashes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a motor with excessive output force is used to overcome high seal loads, then the door can be opened under increased seal load conditions, but the motor size, weight, and cost increase
Solution Approach 1:
The patent divides the motor operation into two distinct modes: normal operation mode with first gear reduction ratio and emergency/high-load mode with second gear reduction ratio. This segmentation allows the motor to use appropriate force multiplication for each condition, avoiding the need for an oversized motor that must continuously handle maximum loads.
Solution Approach 2:
The system dynamically switches between two gear reduction mechanisms based on operational conditions. The control system activates the appropriate gear reduction ratio depending on whether normal or high seal load conditions are detected, enabling the motor to optimize its output force for each specific operating scenario.
2Reliability
If a motor with excessive output force is used to overcome high seal loads, then the door can be opened under increased seal load conditions, but the motor size increases
Solution Approach 1:
The patent divides the motor operation into two distinct modes: normal operation mode with first gear reduction ratio and emergency/high-load mode with second gear reduction ratio. This segmentation allows the motor to use appropriate force multiplication for each condition, avoiding the need for an oversized motor that must continuously handle maximum loads.
Solution Approach 2:
The system dynamically switches between two gear reduction mechanisms based on operational conditions. The control system activates the appropriate gear reduction ratio depending on whether normal or high seal load conditions are detected, enabling the motor to optimize its output force for each specific operating scenario.
3Reliability
If a motor with excessive output force is used to overcome high seal loads, then the door can be opened under increased seal load conditions, but the cost increases
Solution Approach 1:
The patent divides the motor operation into two distinct modes: normal operation mode with first gear reduction ratio and emergency/high-load mode with second gear reduction ratio. This segmentation allows the motor to use appropriate force multiplication for each condition, avoiding the need for an oversized motor that must continuously handle maximum loads.
Solution Approach 2:
The system dynamically switches between two gear reduction mechanisms based on operational conditions. The control system activates the appropriate gear reduction ratio depending on whether normal or high seal load conditions are detected, enabling the motor to optimize its output force for each specific operating scenario.
4Ease of operation
If the pawl is designed to easily release from the ratchet, then normal operation is smooth, but the pawl may inadvertently release during crash conditions
Solution Approach 1:
The patent incorporates a crash detection system that preemptively activates the high seal load mode with increased gear reduction ratio when crash conditions are detected. This preliminary anti-action prevents inadvertent pawl release by providing additional mechanical retention force during impact events.
Solution Approach 2:
The control system continuously monitors operational parameters and switches between gear reduction modes based on detected conditions. During normal operation, the system uses first gear reduction for smooth pawl movement, while during crash conditions, it switches to second gear reduction to prevent inadvertent release, creating a feedback-controlled adaptive system.
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
The solution provides a compact and cost-effective motor that efficiently operates under normal and high seal loads, ensuring the door remains closed during impacts and allows controlled opening when needed.
Implementation Method 1
a multistage reduction mechanism operably connects an output of the powered actuator to the pawl
Implementation Method 2
utilizing different gear reductions to optimize motor size and force
Data Source
AI summary
A latch assembly for a motor vehicle swing door arranged for movement between open and closed positions includes a frame plate and a ratchet operably coupled to the frame plate for movement between a striker capture position and a striker release position. A release chain component is configured for release from a ratchet holding position, whereat the ratchet is maintained in the striker capture position to maintain the vehicle swing door in the closed position, to a ratchet releasing position, whereat the ratchet is moved to the striker release position to allow the vehicle swing door to be moved to the open position. A mechanical feature operably coupled to the frame plate is configured to be deformed by a force in a crash condition to prevent inadvertent movement of the release chain component from the ratchet holding position to the ratchet releasing position.