SOLENOID OPERATED DIRECTIONAL CONTROL VALVES

The solenoid directional control valves of the RS type are used to control the motion of one or more consumers. Usually one 4/3 directional control valve is used in the system, by which the necessary direction of the motion is determined. The flow from it is fed to a directional control valve of the RS type, which specifies which one of the consumers will function. In case of more than two consumers, one additional RS directional control valve is added for every following consumer.

The stacking of the directional control valves (up to 10 units) is realized by pins and nuts, and the sealing between them is fulfilled by frontal O-rings. This pattern provides an economy of one solenoid per each consumer and an improved compactness. Three types of solenoids are manufactured, which differ by the nominal flow – RS04 (10 L/min), RS06 (30 L/min)and RS10 (50 L/min),as the maximum pressure for all of them is 250 bar. RS06..T and RS10..T for maximum pressure of 350 bar are offered out of the options RS06 and RS10.

They have one additional port “T”, which leads the leakages out of the chamber of the directional control valve and has to be connected to the tank. The maximum allowed pressure at port “T” is 200 bar.If a hydraulic lock for the consumer is needed, there is an opportunity for direct assembly of a hydraulic lock type VBD-R-38 (only for a RS06..V directional control valve).

 

HYDRAULIC DIRECTIONAL VALVES WITH AUTOMATIC SWITCHING

This type directional control valves are designed to control the motion of cylinders, assigning them a continuous oscillating movement. The motion switchtakes place when the cylinder reaches the end of its stroke, without any sensor needed to report that. According to the mode of indication of this end position, two kinds of directional control valves are produced.This type directional control valves are designed to control the motion of cylinders, assigning them a continuous oscillating movement. The motion switchtakes place when the cylinder reaches the end of its stroke, without any sensor needed to report that. According to the mode of indication of this end position, two kinds of directional control valves are produced.In the first kind - 4/2RHА..-the switch is as a result of the pressure. At the end of the stroke the pressure peaks up to the value at which the safety valve of the system is adjusted. This results in the switch of the directional control valve and a reverse in the motion of the cylinder. The value of the pressure needed to switch to each direction can be adjusted by a separate valve. The adjustment must not exceed 90% of the adjustment of the safety valve of the system. The switch can also be performed at a random position of the cylinder, as far as the value of the pressure reaches the value of the adjustment needed to make the switch to the corresponding direction. The directional control valves of this type are mostly used in automated press machines, where a motion switch has to be done when reaching a predetermined stress force. They are not suitable for the reverse of the movement of massive parts, where in the course of their acceleration the pressure reaches the value at which the safety valve of the system is adjusted.In the other kind - 4/2RHА..А– after the cylinder comes to the end of its stroke, the flow stops to zero value, thus causing the directional control valve to switch. The motion switch here does not depend on the pressure. To the purpose of providing more reliable work of the directional control valve, its connection to the cylinder needs to be realized by hoses with minimum length of 1000 mm. In case of systems working at great cyclic pressure, the usage of cylinder with regulated buffer at the end of the stroke is recommended.

 

DIRECTIONAL CONTROL VALVE FOR HYDRAULIC TURNING PLOUGH

 

The directional control valve is designed to control the flow of the oil, driving the hydraulic cylinder for turning a tractor-driven plough. When a flow is supplied to the port P of the block, the cylinder makes one full cycle of retraction and extension and keeps hydraulically locked, despite the fact that there is pressure at the input port. It is necessary to wait for 3-4 seconds after the supply of the flow stops, till the next action, in order to restore the position of the switching spool in the directional control valve. On the next flow supply the cycle repeats itself.

 

 

ELECTRO-HYDRAULIC OPERATING UNIT

 The electro-hydraulic operating unit EHO… is designed for coupling to manually operated, hydraulic directional control valves of the P40, P70, P80, P100 and P120 types, which are produced by the Bulgarian company BADESHTNOST AD, as an additional option for electric operation.