Agricultural and forestry tractors are equipped of quick-action hydraulic couplers designed to operate different implements used for agricultural and forestry works. Power supplied by engine can be easy conveyed by high pressure hydraulic fluid in pipes to rotary tools or to cylinders driving apparatus with linear movements on agricultural machinery pulled, pushed or carried by tractors.
Higher available oil flow and the rising number of connections for fluid power present on modern agricultural and forestry tractors increase interest in determination of the performance of their hydraulic system.
Hydraulic power provided by agricultural and forestry tractors can be evaluated using two different standards: a specific section of OECD Code 1 and 2 and ISO 789-10.
A testing rig to able to perform tests in accordance with this two standard has been set up at IMAMOTER.
It is made up of a temperature transducer, two pressure gauge, one at the outlet and one at the inlet of the tractor, a flow meter, an adjustable restrictor valve and a double acting cylinder. All components are closed in a mobile case and are connected, by a conditioning system, to a computer equipped with an acquisition data board and running a software for tests management.
The software for control and acquisition of data from the instrumentation of testing rig used to determine hydraulic power at the hydraulic coupler pairs on agricultural tractors has been developed in graphical LabVIEW environment. It is essentially consisting of two sections. First section, the initialization one, in which the operator can personalize the standard settings of the test (acquisition frequency, acceptable tolerances in measurements and system stabilization, etc.) and can select characteristic parameters of the tractor under test (category, type and viscosity index of hydraulic fluid, engine speed, etc.). A second operating section in which test regulations and data acquisition procedures are actually executed. Both sections are designed to give remarkable importance to the graphical user interface behind which all technological and algorithmical aspects are hidden.
The operational conditions are reached by digital control loops that carry out pressure or flow rate stabilization driving the adjustable restrictor valve. This to facilitate the use of the testing rig to not skilled people.
At the end of test session, measurements are suitably processed and a report is automatically produced.
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