Electronic proportional hydraulics are used on machines requiring a more precise and delicate control over flow and pressure, as well as to reduce shock and pressure spikes on complex circuits.
A standard 4/3 electronically controlled valve block (12v) is actuated by turning a 12vdc supply on and off. When the coil is energised the solenoid armature is shifted fully in one direction and when the power is cut the spring return shifts the armature fully in the opposite direction. This controlling fluid direction, but not speed. Is some applications, this is perfectly allowable, yet not appropriate for the others.
For example, imagine a tractor with a hedge cutter mounted.The tractor is reving at 1700rpm producing a constant oil flow. If the method of electro-hydraulic control was as described above for the hedge cutter, the operator would have no fine adjustment of the boom, thus causing violent and sudden movement of the boom. Eventually the impact loading caused by this would not only damage the hydraulic circuit but would cause metal fatigue on the hedge cutter.
Proportional valves do differ mechanically from direct valves, however the main difference is the use of an electronic amplifier to vary the voltage and current subjected to the coil as the amplifiers input is by computer or operator. For example, a joystick, or a pressure sensor.
Our services within this field are as follows:
- Design and specification of suitable valves and electronics
- Supply of a wide range of proportional hydraulic valves
- Manufacture of control boxes
- Programming of our in-house design of proportional amplifier card
- Implementation into factory lines for automation or operator controlled applications
Call us now for more information on how we may be able to help you.