Modeling, validation, and investigation of an electrohydraulic crimping hand tool

Due to their high power density, hydraulic systems are increasingly adapted for human scale devices. For example, commercial and utility electricians use electrohydraulic cutting and crimping tools, rather than human powered tools, to cut and crimp wires that exceed 25mm in diameter. These tools greatly reduce worker-related fatigue and strain-type injuries. To improve electrohydraulic tool technology, there is a need to increase the number of applications from a single battery charge. This paper develops a high fidelity nonlinear lumped parameter model of an electrohydraulic crimping hand tool used by professional electricians. The eleventh-order model can predict tool performance with an average error of 6.9% and 4.4% with respect to the maximum energy consumption and crimp time, respectively. Simulation studies were conducted to investigate reducing the energy consumption of the tool. An independent parameter sweep was performed on the pump piston diameter. The gear ratio was a dependent parameter linked through the maximum motor torque. Increasing the pump piston diameter while increasing the gear ratio was shown to decrease the energy consumption of the tool during crimping applications. Simulations suggest that up to 30% energy can be saved per crimp by increasing the pump piston diameter and gear train ratio.