Solenoid valves

Solenoid valves

The oil is distributed to the operating cylinders through the set of six solenoid valves.

Each of the six solenoid valves comprises a mobile stem (1) operated by an electromagnet (2) which acts on two needle valves (3) and (4): when the valve is energised the stem lowers and closes the valve (3) and the recirculation duct (towards the reservoir) (A) while the valve (4) and the delivery duct (B) (towards the cylinders) are open.

In the rest condition, with the valve de-energised, all the valves are open so that there is no pressure in the circuit and the hood can be operated manually.

Operation of cylinders

Each pair of cylinders is controlled by two solenoid valves:

• (A) controls the downward stroke of the piston,
• (B) controls its upward stroke

When valve (A) is energised, the pressurised fluid leading from the pump is sent to the cylinder in the upper section (C1), while the fluid flows out of the lower section and returns to the reservoir through valve (B) which is de-energised: this way the piston lowers inside the cylinder

Conversely when valve (B) is energised, the pressurised fluid leading from the pump is sent to the cylinder in the lower section (C2), while the fluid flows out of the upper section and returns to the reservoir through valve (A) which is de-energised: this way the piston rises inside the cylinder