Powerfold Detent Inversion for Impact Compliance
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Solution Overview
Problem
Conventional mirror powerfold assemblies with a detent mechanism located at the bottom can lock, bind, or jam during impact, failing to meet regulations such as the ECE R46 and associated tests like Pendulum and Impact Tests, especially when the motor is outside the mirror head.
Innovation Solution
A modified powerfold assembly with a raised detent mechanism located at the top, allowing the mirror or camera assembly to freely fold inward during impact, reducing resistance and enabling compliance with regulatory tests by unlocking attachments between the detent mechanism and the mirror base.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the detent mechanism is located at the bottom of the powerfold assembly, then the mirror assembly can be securely held in position during normal operation, but the detent mechanism locks, binds, or jams during impact with pedestrian, cyclist, or other object
Solution Approach 1:
The detent mechanism is inverted from its conventional bottom location to a top location on the powerfold assembly. This inversion changes the mechanical interaction during impact: instead of the detent engaging and locking during downward impact forces, the raised top detent allows the mirror assembly to fold inward freely upon impact, preventing binding and jamming while maintaining positional stability during normal operation through gravitational alignment
2Ease of manufacture
If the motor is located outside of the mirror head, then the powerfold assembly can be modular and easier to manufacture, but the mirror assembly resists folding into the vehicle upon impact, making it difficult to pass ECE R46 regulation and associated tests
Solution Approach 1:
By inverting the detent mechanism to the top of the powerfold assembly, the modular motor-outside-mirror-head configuration achieves regulatory compliance. The raised detent position ensures that during impact, the mirror assembly folds inward without the detent interfering, thus passing ECE R46 Pendulum and Impact Tests while retaining the manufacturing advantages of modular design
Solution Approach 2:
The detent mechanism is specifically positioned at the top of the powerfold assembly rather than uniformly distributed or located elsewhere. This localized placement creates a specific mechanical behavior during impact where only the raised detent area engages differently, allowing the rest of the modular assembly to maintain its manufacturing advantages while achieving the required impact response
3Stability of the object's composition
If the detent mechanism mechanically resists movement of the mirror assembly, then the mirror remains stable during driving, but the resistance to movement causes the detent to lock or bind during impact
Solution Approach 1:
Inverting the detent to the top position creates a gravitational alignment where the detent naturally engages to provide stability during normal driving conditions. During impact, the force direction causes the mirror assembly to fold inward, and the raised detent position prevents it from locking or binding, thereby reducing impact damage while maintaining driving stability
Solution Approach 2:
The detent mechanism's effect is made dynamic rather than static: during normal operation, gravity keeps the detent engaged for stability; during impact, the sudden force changes the engagement state, allowing free folding motion. This dynamic behavior resolves the contradiction between stability and impact safety
Data Source
AI summary
A vehicle mirror assembly includes a mirror base configured to attach one or more accessories to the mirror base at an attachment point. The mirror base is attachable to a vehicle door. The vehicle mirror assembly also includes a powerfold assembly. The powerfold assembly includes a motor configured to move the mirror base, a motor assembly shield, a powerfold motor frame surrounding the motor, and a detent mechanism located between the powerfold assembly and the mirror base. The powerfold assembly is located in the vehicle door and is configured to allow movement of the mirror base when the mirror base experiences impact. Methods of manufacturing and operating the mirror assembly are also disclosed.