Riassunto analitico
Flexible hoses are fundamental components that are employed in any vehicle, from conventional passenger automobiles to heavy duty trucks and a wide range of applications as agricultural and construction equipment. They are employed to guarantee the conveyance of a given fluid (usually hydraulic oil, fuel, coolant, air, etc.) for the correct operation of different circuits at the vehicle.
Hoses quality must be guaranteed, especially when upon failure, leakage of the fluid could be present, which will then interact with the surrounding elements of the vehicle, could be perceived by the customer, and will possibly reduce the performance of the vehicle subsystem in which the leakage is present.
This is a source of significant concern at construction equipment, in which a hydraulic oil leakage is a cause of a full machine stop, a problematic situation in the heavy machinery industry in which the vehicles work in a sensitive limited time window and is less simple to replace the affected unit with another one, as compared to passenger vehicles or buses, introducing financial losses for the user.
Nowadays to prevent these issues, there is a deep use of experimental stages, both on test benches and in-field to assess design choices. However, this is not sustainable on the long term and implies additional effort from a financial and time point of view. The development of new tools to enhance virtual testing provides additional opportunities to improve the current approach.
For such reasons, the aim of this work is to propose a design methodology for virtual validation and optimization of hydraulic hoses routing that can be integrated to the current design process with the aim of solving the main lacks of the approach currently adopted.
The methodology is explored, as it permits to consider the hoses mechanical properties, contacts, and gravitational effects. Thanks to collaboration with CNH Industrial at the Modena site, the methodology is employed by using the tool IPS Cable Simulation to perform the study for the next model of the Compact Wheel Loader CASE 321F, vehicle corresponding to the construction equipment segment, by focusing on the hydraulic hoses on the loader arms and quick coupler region of the machine.
The introduction of bending radius, elongation, torsion, and clearance & collision as Key Performance Indicators to evaluate the quality of the routing is discussed. The first loop of the analysis is performed, and collision issues are encountered, which permit the implementation of a successful optimization loop to solve those issues, while maintaining the other KPIs on target, thus generating significant routing improvements even before any prototype build takes place.
The use case selected to assess the proposed method demonstrated the capability to provide in advance the behavior of the routing proposed, and therefore to drive the subsequent improvements. By adopting reference KPIs, virtual validation ensures to meet the expected engineering requirements, while the application of optimization is possible to select the best configuration.
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