Powerfold Exterior Mirror Pivot Locking Against Vibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing exterior rearview mirror assemblies for vehicles lack efficient mechanisms for securely locking the mirror head in place during folding and extended positions, leading to vibration issues and reduced durability due to the pivot washer and mirror head/arm bracket interface weaknesses.
Innovation Solution
The implementation of a powerfold actuator with a conical pivot tube and biasing element that securely aligns the pivot tube with the mounting base, combined with a zero draft insert and spring loaded touchpads or toggle touchpads to enhance stability and durability, and a light module for improved visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pivot washer and mirror head/arm bracket interface is used to connect the mirror head to the mounting base, then the mirror head can be positioned and moved between extended and folded positions, but the interface is weak and prone to vibration issues, reducing durability
Solution Approach 1:
The patent employs a conical pivot tube with a conical interface that mates with a corresponding conical surface in the mounting base. This curved/conical geometry provides superior surface area contact and load distribution compared to a flat pivot washer interface, enhancing the strength and durability of the connection while reducing vibration susceptibility.
Solution Approach 2:
The solution integrates multiple materials and components in the pivot assembly, including the conical pivot tube, biasing element (spring), and detent mechanism, creating a composite structural system that distributes stresses and improves overall interface strength and reliability compared to a single pivot washer design.
2Stability of the object's composition
If the mirror head is made movable between extended and folded positions without a secure locking mechanism, then the mirror can be adjusted for different viewing positions, but the mirror head becomes loose and unstable during operation due to vibrations
Solution Approach 1:
The patent implements a dynamic positioning system where the mirror head can be freely adjusted to various positions during operation, then securely locked into place using a detent mechanism. The biasing element (spring) provides continuous force to maintain engagement with the detent, ensuring stable locking while allowing easy repositioning when needed.
Solution Approach 2:
The detent mechanism acts as an intermediary between the mirror head and mounting base, providing secure locking at specific positions without preventing adjustment. The biasing element serves as a mediator that maintains constant force on the detent, ensuring reliable engagement while allowing the mirror to be repositioned when required.
3Reliability
If a simple pivot mechanism is used to allow mirror head movement, then the structure remains simple, but the mechanism lacks secure locking capability, leading to vibration issues and reduced durability
Solution Approach 1:
The powerfold actuator is divided into distinct functional segments: the conical pivot tube for positioning, the biasing element for maintaining force, and the detent mechanism for locking. This segmentation allows each component to perform its specific function efficiently while keeping the overall design manageable and reliable.
Solution Approach 2:
The conical pivot tube serves multiple functions: it provides the pivot axis for mirror movement, maintains angular positioning through its conical geometry, and works with the biasing element and detent to provide secure locking. This multi-functionality reduces the need for separate components, balancing reliability with controlled complexity.
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 improved stability against vertical vibrations, enhanced durability, and increased visibility with the secure locking mechanism and additional light module features, ensuring reliable operation and optimal rearview functionality.
Implementation Method 1
The powerfold actuator includes a biasing element disposed between the housing of the powerfold actuator and an upper end of the pivot tube, and the biasing element releasably retains the powerfold actuator in at least one detent state of the powerfold actuator.
Implementation Method 2
The lower end of the pivot tube includes a conical portion having an outer conical-shaped surface that engages a corresponding conical portion of the channel of the mounting base.
Data Source
AI summary
A vehicular exterior rearview mirror assembly includes a mirror head movable relative to a mounting base between an extended position and a folded position. An actuator is electrically operable to move the mirror head between the folded and extended positions. A pivot tube extends from the mounting base and through a base portion of the actuator. The pivot tube includes a tapered portion at least partially received at a channel of the mounting base. An inner surface of the channel includes a shape that corresponds to a shape of an outer surface of the tapered portion. A biasing element disposed between a housing of the actuator and an upper end of the pivot tube biases the tapered portion toward engagement with the inner surface of the mounting base along the channel.