Facade Shading Slat Orientation via Shape Memory Wedge Locking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing slat orientation systems for facade solar protection, which use shape memory alloy actuators, require continuous energy to maintain slat positions and lack precision in angular adjustments, leading to inefficiencies and complexity in long-term positioning and precise control.
Innovation Solution
Incorporating controlled wedges that can immobilize the drive carriage in intermediate positions between extreme positions, eliminating the need for continuous energy and enhancing precision by using shape memory alloy actuators in conjunction with elastic return mechanisms and Joule effect heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If shape memory alloy actuators are used to control slat orientation, then the system eliminates motors and reduces noise, but continuous energy is required to maintain slat positions
Solution Approach 1:
A wedge element is introduced as an intermediary between the drive carriage and the slats. This wedge can be positioned to mechanically lock the drive carriage at specific locations along its path, allowing the slats to maintain their angular position without continuous power to the shape memory alloy actuator. The wedge acts as a passive mechanical holder that releases and engages to maintain position.
Solution Approach 2:
The shape memory alloy actuator operates periodically rather than continuously - it is activated only when position changes are needed to move the drive carriage and slats to new orientations. Once positioned, the wedge maintains the position passively without requiring continuous energy input, enabling periodic rather than continuous actuation.
2Device complexity
If shape memory alloy actuators are used for slat orientation, then the system simplifies the drive mechanism, but precision in angular adjustments is reduced
Solution Approach 1:
The wedge element serves as a precision positioning intermediary with specific geometric features that engage with corresponding features on the drive carriage. This mechanical interface provides precise angular positioning by defining specific engagement points along the carriage path, thereby improving angular adjustment precision despite the simplified actuator mechanism.
Solution Approach 2:
The system utilizes controlled temperature variation of the shape memory alloy actuator to achieve precise positioning. By carefully controlling the thermal parameters (heating rate, temperature range, cooling rate), the actuator can be made to stop at specific positions where the wedge can engage, thereby achieving precise angular adjustments through parameter control.
3Ease of operation
If the drive carriage is allowed to move freely between extreme positions, then the system improves ease of operation, but the ability to maintain intermediate positions is lost
Solution Approach 1:
The wedge element acts as a selective intermediary that can engage to stabilize the drive carriage at specific intermediate positions along its path. The wedge is positioned such that it can engage with the moving carriage to hold it steady at desired locations, providing position stability while still allowing the carriage to move freely between positions when the wedge is disengaged.
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
Enables precise and energy-efficient maintenance of slat positions without continuous heating, improving durability and reducing energy consumption, while allowing for precise angular adjustments of slats for optimal solar protection.
Implementation Method 1
a controlled actuator (31) for the movements of the drive carriage, comprising a variable-length element (34) made of a shape-memory material, the length of which varies according to its temperature
Implementation Method 2
The variable length shape memory element (32) of the controlled actuator (31) is a longitudinal wire element made of a shape memory alloy whose controlled temperature variation is achieved by heating this wire element by Joule effect
Implementation Method 3
a drive carriage (37) which is translationally mobile in both directions along a longitudinal direction orthogonal to the pivot axes (22) of the slats (20) and over a determined stroke between a first extreme position towards which it is elastically returned by a spring (34) and a second extreme position
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a system and a method for protecting a facade comprising a series of slats (24), each of which is pivotable in both directions, and a slat drive device (24) comprising a carriage (44) for pivoting the slats, an actuator for the carriage (44) for the drive which includes a wire (52) made of a shape memory material, characterized in that the system includes a controlled wedge (60) for adjusting the angular orientation of the slats (24) which is mounted movably between a retracted position and an active wedge position in which the wedge (60) immobilizes the carriage (44) for the drive in a longitudinal position intermediate between its two extreme positions.