Load Cell Overload Beam Fracture for Hygiene
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Solution Overview
Problem
Existing load cells in dynamic weighing applications face challenges with high precision, overload capacity, and hygiene requirements, as they are prone to damage from vibrations and accumulate dust and bacteria, leading to metrology issues and reduced lifespan.
Innovation Solution
A load cell design with an internal overload protection mechanism featuring a strain hole with an overload beam that fractures to create a gap for protection, combined with sealed strain gages and adjustable notches for balanced strain distribution, enhancing lateral and torsion resistance while preventing dust accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If external overload protection is added to load cells, then overload capacity is improved, but dust and bacteria accumulate in the gaps affecting metrology and food hygiene
Solution Approach 1:
The overload protection mechanism is nested within the strain hole of the elastic body, with the overload beam integrated into the strain part structure. This internal nesting eliminates external gaps where dust could accumulate while maintaining overload protection functionality through the fracture mechanism of the overload beam.
Solution Approach 2:
The overload protection function is extracted from an external additive structure and integrated directly into the strain part of the load cell. The overload beam is formed as part of the strain part itself, removing the need for separate external protection components that would create cleaning difficulties.
2Measurement precision
If sensitive beams are made thinner for low capacity applications, then measurement precision is improved, but the load cell becomes more prone to destruction in dynamic weighing
Solution Approach 1:
The overload beam is designed with a predetermined fracture point that acts as a sacrificial element. Before the thin sensitive beams can be destroyed by excessive dynamic loads, the overload beam fractures first, absorbing the harmful forces and protecting the precision measurement elements while allowing the thin-beam design to maintain its sensitivity.
3Ease of manufacture
If the load cell structure is simplified for ease of manufacture, then manufacturing cost is reduced, but lateral and overload protection may be compromised
Solution Approach 1:
The overload protection mechanism is merged with the strain part in a unified structure. The overload beam is formed as an integral part of the strain part, sharing the same material and manufacturing process. This merging eliminates the need for separate protection components, simplifying manufacture while providing robust protection through the fracture 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
The design provides robust overload protection, increased lifespan, and easy cleaning, ensuring high precision and hygiene standards in dynamic weighing applications, while maintaining high natural frequency and overload capacity.
Implementation Method 1
The strain part comprises a strain hole, stain gages fixed in the strain hole
Implementation Method 2
A seal welded on the load cell seals the strain hole to protect the strain gages
Implementation Method 3
An overload protection mechanism disposed in the strain hole has an overload gap β... the overload protection mechanism comprises an overload beam disposed in the strain hole and the overload beam fractures
Data Source
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AI summary
The invention relates to a load cell counterforce. The counterforce comprises a fixed part and a strain part. The fixed part comprises a PCB mounting hole and a PCB. The PCB connects with a cable gland. The strain part comprises a strain hole, stain gages fixed in the strain hole. Seals fixed on the counterforce are to seal the strain hole. The strain hole comprises an overload protection mechanism which has overload gap β. On the other hand, the fixed part comprises a PCB mounting hole and a pair of strain gages. The counterforce has a cross-shaped overload beam in the stain hole. The present invention is directed to a load cell counterforce with an internal overload protection mechanism. The load cell counterforce has good lateral and overload protection. And it's easy to be machined. Dusts cannot accumulate in the gaps. It can meet the requirement of food hygiene.