Reliability, flexibilty and safety are key elements to any hydraulic system. This is why Thomas Magnete GmbH launched the EHA electrohydraulic actuator at Bauma last month. This compact, self-regulating hydraulic control unit is designed for use in all kinds of work machines.
The actuator consists of two proportional pressure-reducing valves encased within a single electronic control unit with a redundant sensor system. It transforms electric signals that originate from a control unit into physical quantities. The vehicle’s control unit communicates with the installed EHA-units via a bus signal.
Once the user moves the vehicle’s joystick, the electrohydraulic actuator controls the client’s system through both valves. The integrated linear sensor serves an additional safety purpose by closing the control loop via the position signal. A microcontroller installed within the EHA board picks up the actual signal of the linear sensor, compares it with the command signal of the operator, and automatically adjusts the proportional valves accordingly via the operating pressure.
It is possible to activate up to 30 different modular functions, which realize an individual initial setup of the different hydraulic functions of a machine. This happens quite easily through a graphic interface. This way, adjustments during ongoing operation can be executed flexibly at all times.
The electrohydraulic actuator also features a particular diagnostic function which ensures the safety of the client’s system. It even works unimpeachably when subjected to various forms of interference, be it different operating temperatures, flows or fluctuations of power supply.
This enables it to be used in machinery with stringent safety requirements. The integrated mutual parameter back-up is optionally available. Neighboring EHAs store each other’s setting parameters on the same machine. If one device is replaced, the settings are automatically carried over to the new device. Thus, there is no need for a time-consuming manual data transmission.
The EHA was developed in accordance with valid standards for the development of safety-related electronic systems IEC 61508, DIN EN ISO 13849, ISO 25119/DIN EN 16590 und ISO 26262.
Thomas Magnete GmbH
www.thomas-magnete.com
Filed Under: Mobile Hydraulic Tips