Vehicle Seat Back Lock Mechanism with Cam-Return Spring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle seat-back lock mechanisms fail to securely lock the backrest in the upright position against external forces such as cargo or sudden deceleration, and lack an efficient mechanism for easy folding and reconfiguration between upright and flat positions for cargo loading.
Innovation Solution
A seat-back motion controller with a seat-back lock mechanism that includes a blocker, cam-return spring, and a sector plate, coupled with a pinion gear and actuation device, allows for secure locking and controlled pivoting of the seat back between upright and flat positions using a motor-driven actuation system, ensuring stability and ease of use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple lock mechanism is used, then the device complexity is reduced, but the reliability of locking the backrest against external forces deteriorates
Solution Approach 1:
The lock mechanism is segmented into distinct functional components: a blocker element for engagement, a cam-return spring for automatic resetting, and a sector plate with defined engagement zones. This segmentation allows each component to perform its specific function efficiently while maintaining overall system reliability without excessive complexity.
Solution Approach 2:
The cam-return spring is pre-loaded and positioned to automatically engage the blocker in the locked position before any external force is applied. This preliminary action ensures the backrest is secured against cargo or sudden deceleration forces without requiring additional active control systems.
2Reliability
If a secure lock mechanism is implemented, then the reliability of the upright position is improved, but the ease of operation for folding deteriorates
Solution Approach 1:
The lock mechanism transitions dynamically between locked and unlocked states based on the backrest position. The cam-return spring automatically disengages the blocker when the backrest reaches the folded position, and automatically re-engages it when the backrest returns to upright, eliminating the need for manual intervention and maintaining ease of operation.
Solution Approach 2:
The cam-return spring performs self-service by automatically resetting the lock mechanism to the engaged position after folding operations. This self-resetting capability maintains reliable locking without requiring additional actuators or manual operations, preserving ease of use while ensuring upright position stability.
3Ease of operation
If a motor-driven actuation system is used, then the ease of operation is improved, but the device complexity increases
Solution Approach 1:
The motor-driven actuation system is merged with the existing lock mechanism components. The same motor and transmission elements that drive the backrest folding also control the lock/unlock transitions through the sector plate and cam-return spring assembly. This merging reduces overall system complexity by eliminating separate actuation systems while maintaining ease of operation.
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 secure resistance to external forces in the upright position while enabling easy conversion to a flat position for cargo loading, enhancing safety and usability by maintaining the seat back's structural integrity and facilitating easy operation through a user-friendly interface.
Implementation Method 1
a cam-return spring, and a sector plate
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A vehicle seat includes a seat base and a seat back coupled to the seat base. The seat back moves about a seat-back pivot axis from an upright position to a fold-flat position.