Vehicle Door Latch Lever Decoupling for Motor Failure Override
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical door latch devices can become disabled when the motor fails to operate, preventing the door from being locked to the striker, compromising safety and theft prevention.
Innovation Solution
A door latch device with a manual cancellation mechanism that allows the latch disabled state to be canceled by a manual operation, independent of the motor, and a vehicle interior operation disabling mechanism to enhance safety and theft prevention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an electrical door latch device is used with motor-driven release mechanism, then the door can be easily opened by electrical actuation, but the device becomes unreliable when the motor fails to operate
Solution Approach 1:
The release lever is divided into a first lever (operated by motor) and a second lever (engaged with latch mechanism), which can be coupled or decoupled independently. This segmentation allows the manual release mechanism to operate the latch through the second lever even when the motor-driven first lever fails, resolving the contradiction between ease of electrical operation and reliability of door closure.
Solution Approach 2:
The system changes the operational state parameter of the levers from a fixed coupled state to a variable state where coupling can be switched on or off. The control mechanism allows switching between motor-driven operation and manual operation modes, enabling the system to adapt to motor failure conditions and maintain reliable door closure capability.
2Reliability
If a manual release mechanism is added to the electrical door latch device, then the reliability of door closure is improved, but the device complexity increases
Solution Approach 1:
The manual release mechanism is merged with the existing electrical release mechanism by using a common second lever that can be operated by both the motor-driven first lever and the manual operation portion. This integration allows the manual release function to be added without requiring a completely separate mechanism, thus improving reliability while minimizing the increase in device complexity.
Solution Approach 2:
The second lever serves dual functions: it can be actuated by the motor-driven first lever for normal electrical operation, and it can also be directly operated by the manual operation portion when the motor fails. This multi-functionality allows a single component to fulfill both automated and manual release requirements, reducing overall system complexity.
3Productivity
If the first lever and second lever are always coupled, then the motor operation is efficient, but the manual release mechanism cannot operate when motor fails
Solution Approach 1:
The coupling between the first lever and second lever is made dynamic rather than fixed. The control mechanism enables the coupling state to change based on operational needs: coupled during normal motor operation for efficiency, and decoupled when manual operation is required due to motor failure. This dynamic adaptability resolves the contradiction between operational efficiency and emergency reliability.
Solution Approach 2:
The control mechanism acts as an intermediary that manages the coupling state between the first lever and second lever. It can disconnect the coupling to allow manual operation of the second lever when the motor fails, while maintaining coupling during normal operation for efficient motor-driven performance. This intermediary control enables the system to switch between operational modes as needed.
Data Source
AI summary
A door latch device has a latch mechanism maintaining a door in a closed state, an electric release mechanism canceling a latched state by driving a motor, and a manual release mechanism canceling the latched state by a manual operation. The electric release mechanism includes an electric release lever operated by driving the motor. The electric release lever includes a first lever operated by driving the motor, and a second lever engaged with the latch mechanism. The manual release mechanism includes an inner lever operated by manually operating a vehicle interior operation portion. The door latch device further has a cancellation mechanism canceling a coupled state between the first lever and the second lever by an operation force of the vehicle interior operation portion, and a vehicle interior operation disabling mechanism selectively switching between a set state and an unset state.