Requirement
Build an in-line weight checking system in the logistics and handling sector.
The project is designed for the transit and weighing of pallets weighing up to 3000 kg with standard dimensions (1200x800 mm) on a motorized roller conveyor, in a system where the PLC is positioned well away from the weighing system.
The roller conveyor has dimensions of 1500 mm x 850 mm and the unladen weight of just the mechanical structure (tare) is 1000 kg.
At the moment of weighing the pallet is to be placed on the roller conveyor by a lift truck, which is why it is necessary to design a static weighing system that takes into account any dynamic stresses caused by impact.
Our solution
The system consists of:
The total full scale of the system is 8000 kg. This is obtained by multiplying the capacity of each individual load cell (2000 kg) by the total number of load cells employed (4).
Knowing the system's full scale is very important. In order to avoid damage to the load cells due to accidental dynamic overloads, it is in fact good practice to have these types of systems work at a maximum of 60/70% of their capacity.
How does it work?
A motor and a photocell are also mounted on the structure.
A forklift truck rests the pallet on the motorized roller conveyor, which allows the pallet to slide to the point where the photocell is located.
When the pallet passes, the photocell is obscured and stops the system.
The pallet is thus located in the middle of the structure, right at the exact point where it is going to be weighed.
This is the moment when static weighing takes place and the measured weight is transmitted to the PLC via the Profinet fieldbus.
Once the weight has been recorded, the PLC instructs the system to restart.
Added value
With this solution and a few small precautions, the pallet is weighed in complete safety, avoiding potential damage to the weighing system caused by overloading or accidental knocks.
What makes the weighing system so safe and functional?
Weight transmitters
Weight transmitters
Shear beam load cells
Shear beam load cells
Mounting Kits for load cells
Weight transmitters