BMG – distributors of the Hydraforce range of proportional valves in southern Africa – works closely with Hydraforce engineers and customers in diverse industries to design and manufacture customised hydraulic control solutions.
That’s according to Ryno Landman, Product Manager, Hydraulics, Fluid Technology High Pressure division, BMG, who said a thorough understanding of the latest fluid power technologies is critical for the design of efficient and cost-effective hydraulic systems.
“Coupled with technical expertise, is the need for the selection of high-performance valves and controllers, which must be installed and supported by a team of hands-on specialists.”
Landman said the range of HydraForce electro-proportional valves supplied by BMG are suitable for use in many applications in agriculture, construction, materials handling, fluid conveyance, mining and quarrying.
“Hydraforce hydraulic cartridge valves and controls are subjected to rigorous field testing and are proven for dependable operation in heavy-duty conditions. Efficiency, response times and signal integrity are optimised using Pulse Width Modulation (PWM) digital signal logic.”
He said PWM works by pulsating DC current and varying the amount of time that each pulse stays ‘on’ to control the amount of current that flows to a device.
“PWM is digital, which means that it has two states – on and off. The main advantage of PWM is that power loss in the switching devices is negligible. When a switch is off, there is virtually no current and when it is on and power is being transferred to the load, there is a minimal voltage drop across the switch.”
BMG’s range of Hydraforce proportional valves includes flow control (PV) and pressure compensating flow regulator valves (PFR), directional control (SP) and pressure control (TS) valves, with a focus on proportional control.
Unlike directional control valves, which allows full flow when energised – proportional control directional valves control flow proportional to an electrical input signal. In pressure regulating / limiting valves this signal corresponds to a pressure setting.
Proportional valves provide a change in output pressure or flow in the same ratio as the change in the input signal. For example, a 4mA to 20mA input signal may correspond to a 50bar to 200bar pressure setting. If the input signal is 4 mA, then the output pressure setting will be 50bar.
As it gradually increases to 20mA, so too does the pressure setting increase to 200bar. This feature offers machine cycles, which are safely operated at greater speeds, with controlled start and stop characteristics. Regulated acceleration and deceleration results in improved overall machine cycle times and enhanced production rates.
Hydraforce has compiled a quick-reference electronics guide, designed to assist with the selection of the best controller for every application. The configurator platform, HF-Impulse is available from the HydraForce electronics portal: http://hydraforce.com/Literature/BUL_Electronic%20Products_10-2018.pdf.