Suction Device for SMA Wire Handling in Actuator Assembly

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Solution Overview

Problem

Existing methods for handling Shape Memory Alloy (SMA) wires in actuator assembly, such as in miniature cameras, are prone to damage and result in significant wire wastage due to the use of mechanical grippers, which are difficult to position accurately, especially in compact designs with multiple wires, leading to inefficient crimping processes.

Innovation Solution

A suction device using gas pressure to manipulate and hold SMA wires along an edge, eliminating the need for mechanical grippers, thereby reducing damage and wastage, and allowing for more precise and efficient crimping of multiple wires simultaneously.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If mechanical grippers are used to hold and position SMA wires during crimping, then the wires can be manipulated and positioned for crimping, but the wires are prone to damage and significant wire wastage occurs

Engineering Contradiction:
Improvewire manipulationVSAvoidwire wastage
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

The patent replaces mechanical grippers with a suction-based positioning system. The suction device uses gas pressure differential (vacuum) to hold and position the SMA wires along the edge of the device, eliminating direct mechanical contact that causes damage and wastage during the crimping process

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention employs pneumatic principles through the suction device that uses gas pressure to manipulate and hold the SMA wires. The suction openings create a vacuum field that captures and positions the wires without mechanical contact, reducing damage and enabling more efficient material utilization

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Ease of operation

If mechanical grippers are used to position wires for crimping, then wire handling is possible, but the grippers are difficult to position accurately, especially in compact designs with multiple wires

Engineering Contradiction:
Improvewire positioningVSAvoidpositioning accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The suction device replaces bulky mechanical grippers with a planar array of suction openings along the edge. This allows precise positioning of multiple wires simultaneously in compact spaces, as the suction force can be applied at multiple discrete locations without the spatial constraints of mechanical gripper structures

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The suction device is segmented into multiple independent suction openings distributed along the edge. Each opening can independently capture and position individual wires, enabling precise multi-wire positioning in compact configurations without interference between positioning elements

Inventive Principle:
Principle #1Segmentation

3Productivity

If mechanical grippers are used to hold wires outside crimps, then wires can be presented to crimps for closing, but the bulk of grippers interferes with crimping multiple wires simultaneously

Engineering Contradiction:
Improvecrimping efficiencyVSAvoidgripper bulk
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The suction device replaces bulky mechanical grippers with a flat, distributed array of suction openings. This eliminates the spatial bulk that prevents simultaneous crimping of multiple wires, allowing all wires to be held and positioned in close proximity to their respective crimps without interference

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention transitions from three-dimensional mechanical gripper structures to a two-dimensional planar arrangement of suction openings along the edge. This dimensional change allows multiple wires to be positioned and held in a compact plane, enabling simultaneous crimping operations without the spatial interference caused by bulky grippers

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 suction device effectively reduces wire damage and wastage by using gas pressure to position and hold SMA wires, enabling accurate crimping of all wires in a single operation without the bulk and interference issues associated with mechanical grippers, thus improving the efficiency of SMA actuator assembly processes.

Implementation Method 1

The suction device is configured to hold a piece of SMA wire along the edge of the suction device by gas pressure generated by suction

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP3423715B1SMA wire handling with air suction
Publication Date: 2022.02.16 CAMBRIDGE MECHATRONICS
  • EP3423715B1 patent drawingFigure 1
  • EP3423715B1 patent drawingFigure 2
  • EP3423715B1 patent drawingFigure 3

AI summary

A suction device holds an SMA wire to a profiled edge, in order to accurately position a length of SMA wire during manufacture of an SMA actuator. The wire is held by air pressure, avoiding damage of the wire or its surface. Once the wire has been offered up to crimps on the actuator sub-assembly and the crimps closed, suction is turned off, releasing the wire in position. The device and process of the invention reduce wire wastage and increase manufacturing throughput.