Cut-off bar actuation using electromagnet and permanent magnet
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor vehicle headlamp systems require large and costly mechanisms to control the cut-off bar for adjusting light beam patterns, with safety concerns and high return torque requirements, and previous magnetic solutions are unsuitable due to temperature limitations of halogen lamps.
Innovation Solution
A switch bar control mechanism using an electromagnet with a ferromagnetic core and a permanent magnet, where the magnet is attracted to the core without current and repelled with current flow, allowing for a lighter and less complex system, and incorporating a return spring to facilitate precise positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional motor and spring mechanism is used to control the cut-off bar, then the bar can be positioned between two angular positions, but the mechanism requires a large motor and high return torque spring due to safety requirements
Solution Approach 1:
The patent replaces the traditional mechanical motor and spring system with an electromagnetic actuation system. The electromagnet uses magnetic fields to directly actuate the cut-off bar, eliminating the need for complex mechanical transmission components, large motors, and high-torque springs while maintaining reliable positioning between dipped beam and main beam positions
2Device complexity
If a magnetic attraction mechanism is used to control the bar, then the system becomes lighter and less complex, but the magnet components risk demagnetization due to high temperatures from halogen lamps
Solution Approach 1:
The patent changes the thermal parameter conditions by transitioning from halogen lamp technology to LED or laser lamp technology. These alternative lighting technologies operate at significantly lower temperatures compared to halogen lamps, thereby eliminating the demagnetization risk for the permanent magnet components while enabling the use of simpler magnetic attraction mechanisms
3Illumination intensity
If halogen lamps are used, then the lighting function is provided, but the high temperature causes demagnetization of magnetic components
Solution Approach 1:
The patent changes the operational parameters of the lighting system by replacing halogen lamps with LED or laser lamp technologies. This substitution maintains the required illumination intensity for vehicle headlighting while dramatically reducing the operating temperature, thereby preventing demagnetization of permanent magnet components in the cut-off bar actuation mechanism
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 solution reduces the size, cost, and complexity of the headlamp control mechanism while ensuring safe and precise adjustment of the light beam, addressing the limitations of previous technologies and temperature issues with new lamp types.
Implementation Method 1
said permanent magnet being attracted in the direction of said ferromagnetic core in the absence of flow of a current in said induction coil
Implementation Method 2
said permanent magnet being pushed away from the ferromagnetic core when a current flows in said induction coil
Data Source
Figure 1~3
Figure 4~6
Figure 7~8
AI summary
A motor vehicle headlight cut-off mechanism comprising a bar (5) formed by a shutter plate carried by a movable assembly configured to move said plate in a plane and thus more or less block a light beam so as to change the optical operating mode, further comprising an actuation mechanism (3) of said movable assembly by means of an electromagnet (9) comprising an induction coil associated with a ferromagnetic core, characterized in that said electromagnet comprises at least one ferromagnetic core fixed relative to its induction coil and in that said movable assembly comprises at least one permanent magnet (54) configured to cooperate magnetically with said ferromagnetic core.