Seat with armrest, and armrest unlocking device for use therewith
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Solution Overview
Problem
The locking mechanism of armrests in vehicles can be unintentionally unlocked due to gravitational acceleration during collisions, and existing solutions require larger anti-G springs to prevent this, which increases the size of the spring.
Innovation Solution
An armrest unlocking device with a lock gear biased by an elastic member, where the rotation center is aligned with the gravity center, reducing the need for a large anti-G spring by minimizing the moment of inertia during collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional locking mechanism with offset rotation center is used, then the armrest can be locked securely, but the anti-G spring becomes large in size due to gravitational acceleration during collisions
Solution Approach 1:
The rotation center of the lock gear is positioned at its gravity center, creating an equipotential condition where gravitational force acts directly through the rotation axis. This eliminates the gravitational moment arm that would otherwise cause the lock gear to rotate unintentionally during vehicle collisions, allowing a smaller anti-G spring to suffice for maintaining locking reliability.
Solution Approach 2:
The position parameter of the rotation center is changed from an offset location to the gravity center location. This parameter change fundamentally alters the mechanical behavior under gravitational acceleration, reducing the required spring force and allowing for a more compact anti-G spring design while maintaining reliable locking.
2Ease of operation
If the rotation center is offset from the gravity center, then the lock gear can be actuated by the spring, but gravitational acceleration causes unintended unlocking during collisions
Solution Approach 1:
By positioning the rotation center at the gravity center, the system achieves equipotentiality where gravitational force creates no rotational moment. This eliminates the reliability issue of unintended unlocking during collisions while the elastic member provides the necessary actuation force for normal locking operation.
Solution Approach 2:
The elastic member acts as a counterweight mechanism, providing the necessary actuation force to overcome gravitational effects during normal operation, while the gravity-center alignment ensures gravitational forces do not interfere with locking stability during collisions.
3Reliability
If a larger anti-G spring is used to prevent unlocking during collisions, then reliability improves, but the device size increases
Solution Approach 1:
The gravity-center alignment creates an equipotential system where gravitational acceleration during collisions produces no rotational moment on the lock gear. This fundamentally reduces the anti-G spring size requirement compared to conventional offset designs, as the spring only needs to prevent unlocking from normal vibration, not counteract gravitational moments during collisions.
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 configuration allows for a smaller anti-G spring, preventing unintended unlocking during vehicle collisions while maintaining effective locking functionality.
Implementation Method 1
a lock gear (15) configured to be biased by an elastic member (17) and rotated about a rotation center (16) of the lock gear (15)
Implementation Method 2
the rotation center (16) is matched with a gravity center position
Data Source
AI summary
In the case of a seat with an armrest on an automobile, an armrest lock mechanism may be released by, for example, the gravitational acceleration (G) in the event of vehicle collision. Accordingly, it is necessary to provide an anti-G spring for biasing to prevent the lock mechanism from being easily released. The purpose of the present invention is to provide an armrest unlocking device that enables a decrease in size of the anti-G spring. In order to solve the problem, provided is an armrest unlocking device in gear, the device operating such that the locking of the lock gear and the sector gear can be released by operating a lever link bracket so as to raise the lock gear, wherein the lock gear has a center of rotation thereof aligned with the position of the center of gravity.