Vehicle Door Handle Assembly with Dual-Threshold Inertial Blocking
Solution Overview
Problem
Existing vehicle door handle assemblies struggle to efficiently block door openings during a wide range of crashes, particularly due to varying accelerations, which can lead to inefficient or damaged inertial mechanisms.
Innovation Solution
A vehicle door handle assembly with a dual inertial blocking mechanism featuring a first and second inertial mass, each reacting to different acceleration thresholds, and stops to prevent excessive rotation, utilizing elastic means and a pin for overlapping motion, ensuring reliable operation across crash severities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single inertial mass is used in the blocking mechanism, then the device complexity is reduced, but the reliability of blocking across a wide range of crash accelerations deteriorates
Solution Approach 1:
The inertial blocking mechanism is divided into two independent inertial masses (first and second inertial masses), each responsible for blocking at different acceleration thresholds. The first inertial mass handles lower accelerations (e.g., 10-20G) while the second handles higher accelerations (e.g., 30-50G), ensuring comprehensive coverage across the full crash spectrum without requiring an overly complex single-mass system.
Solution Approach 2:
The first inertial mass is positioned within the rotational path of the second inertial mass, creating a nested configuration. When the second inertial mass rotates at high acceleration, its pin engages and pushes the first inertial mass into its blocking position. This nested arrangement allows one inertial mechanism to activate and assist the other, ensuring reliable blocking across both low and high acceleration ranges while maintaining a compact structure.
2Speed
If the inertial masses are allowed to rotate freely to their active positions, then the blocking response is faster, but the risk of damage to the inertial mechanism increases
Solution Approach 1:
The stops are pre-positioned in the mechanism housing at specific angular positions before any crash occurs. When acceleration causes the inertial masses to rotate, these pre-positioned stops automatically engage to limit the rotation range, preventing excessive movement that could damage pins, bearings, or other mechanism components while still allowing sufficient rotation for effective blocking.
Solution Approach 2:
The stops act as pre-prepared protective elements that cushion the inertial masses against over-rotation damage. By having these mechanical limits in place beforehand, the system protects itself from the harmful effects of uncontrolled rotation during high-intensity crashes, ensuring the mechanism survives repeated crash events without degradation.
3Manufacturing precision
If the stops are positioned at the same angular position for both inertial masses, then the manufacturing precision is improved, but the functionality to account for pin flexion deteriorates
Solution Approach 1:
Each inertial mass system has its stop positioned at a locally optimized angular position tailored to its specific mechanical characteristics. The second stop is positioned at a different angle than the first stop to account for the flexion and geometric characteristics of the pin connecting the second inertial mass. This localized customization ensures each inertial path achieves optimal blocking angles despite manufacturing variations and dynamic flexion during crash events.
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 dual inertial blocking mechanism effectively prevents door opening during crashes by using two inertial masses and stops to manage a broad range of accelerations, reducing the risk of damage and ensuring functionality post-crash.
Implementation Method 1
a first inertial mass configured for rotating around a second axis between a rest position and an active position wherein the first inertial mass is configured for blocking the rotation of the rotatable lever in its active position, the rotation of the first inertial mass being associated with a first predetermined acceleration
Implementation Method 2
a second inertial mass configured for rotating around the second axis between a rest position and an active position wherein the first and the second inertial masses comprise an overlapping part so that the second inertial mass pushes the first inertial mass towards its active position when the second inertial mass is rotated towards its active position, the rotation of the second inertial mass being associated with a second predetermined acceleration higher than the first acceleration
Implementation Method 3
a first elastic mean configured for constraining the first inertial mass in its rest position
Implementation Method 4
a second elastic mean configured for constraining the second inertial mass in its rest position
Data Source
AI summary
A vehicle door handle assembly includes a rotatable lever for rotating around a first axis between a rest position and an active position for opening the vehicle door, an inertial blocking mechanism including a first inertial mass for rotating around a second axis between a rest position and an active position, a second inertial mass for rotating around the second axis between a rest position and an active position, a first stop for stopping the rotation of the first inertial mass when the first inertial mass is in its active position, and a second stop for stopping the rotation of the second inertial mass when the second inertial mass is its active position. The rotation of the first inertial mass is associated with a first predetermined acceleration. The rotation of the second inertial mass is associated with a second predetermined acceleration higher than the first acceleration.