Vehicle Lens Wiper Using Shape Memory Alloy Kinematics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wiper devices for motor vehicle optical devices face high torque issues due to the conversion of torsional movement into rotary movement, requiring significant driving force, which is inefficient and costly.
Innovation Solution
The wiper device employs a kinematic system allowing the wiping element to transition from one end position to another via a translational movement, utilizing shape memory elements and guide means, such as guide rails and carriage elements, to reduce torque and enhance cleaning efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If torsional movement is converted into rotary movement using torsion bars, then the wiper element can be transferred between end positions, but high torques occur requiring significant driving force
Solution Approach 1:
The patent replaces the traditional mechanical torsion bar system with a shape memory alloy-based drive mechanism. The shape memory element directly converts electrical energy to mechanical displacement through phase transformation, eliminating the need for torsional movement conversion and reducing the driving force requirement.
Solution Approach 2:
The patent utilizes the phase transformation parameter change in shape memory alloy (from austenite to martensite phase) to achieve controlled displacement. This parameter change allows the drive mechanism to produce motion through material property transformation rather than mechanical torque conversion.
2Force
If shape memory elements are used in drive means, then torque requirements are reduced, but the system requires thermal activation control
Solution Approach 1:
The patent exploits the reversible phase transition of shape memory alloy between austenite and martensite phases. Electrical heating triggers the phase change, which directly produces mechanical displacement. The phase transition inherently provides the actuation mechanism, simplifying the overall control system despite the thermal activation requirement.
Solution Approach 2:
The patent utilizes thermal expansion and phase transformation of the shape memory alloy element. When electrically heated, the material undergoes phase change and dimensional change, directly converting thermal energy to mechanical work without requiring complex intermediate mechanisms.
3Force
If guide means are added to enforce translational movement, then kinematics are improved and torque is reduced, but device complexity increases
Solution Approach 1:
The guide means creates a constrained path that ensures the drive unit moves along an optimal trajectory. By providing physical guidance, the system maintains consistent contact between the wiping element and optical component throughout the motion, ensuring uniform cleaning performance.
Solution Approach 2:
The guide means acts as an intermediary between the shape memory drive element and the wiping element. It translates the complex motion of the shape memory alloy into controlled translational movement, ensuring proper kinematics while reducing the torque required for operation.
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 design reduces torque requirements, ensures homogeneous contact pressure for improved cleaning, and allows for cost-effective and efficient operation with automatic return mechanisms, increasing the service life of the wiping element.
Implementation Method 1
at least one shape memory element at least in sections
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a wiping device (2) for an optical device (4) of a motor vehicle, comprising at least one wiping element (6) which is movable over a surface of a disc- and/or dome-shaped optical element (8) of the optical device (4) when moving from a first end position to a second end position, and comprising at least one drive unit (10) which includes at least one retaining means (16) for fixing the wiping element (6) to the drive unit (10) as well as at least one first drive means (12) and at least one second drive means (14), of which at least one drive means (12, 14) has at least a shape memory element at least partially.It is characterized by the fact that the first drive means (12) and/or the second drive means (14) comprises at least one kinematics by which the wiper element (6) can be moved from the first end position to the second end position by a translational movement, in particular a linear movement.