PNEUMATIC CIRCUIT

    The Pneumatic circuit consist of components like.
    1. Compressor
    2. Service unit
    3. Inline slide Valve
    4. Spool Valve
    5. Flow Control Valve
    6. Cylinder.
        
The Cylinder's piston is moved back and front by the help of the compressed air with the help of the pneumatic circuit. The atmospheric air is compressed with the help of compressor, let the pressure be measured in bars. The compressed air is given to the service unit.
       
The Service unit is nothing but the Filter, Regulator, and Lubricator. The air filter cleans the compressed air and the pneumatic system with the help of pressure gauge attached to it. The regulated air is lubricated with help of Lubricator. The filtered, regulated, lubricated air is passed to the cylinder via three types of valves. First it passes through the inline slide valve which helps to evacuate the unnecessary air at rest condition from the pneumatic system and for the additional control of the air flow, Second it passes to the spool valve( V2 ) which is normally open. This valve is used to change the direction of the air as required to move the piston.


The current controls the spool valve. When no current flows through the solenoid coil of spool valve at normally open condition the airflow is in one direction and when the current is applied the airflow is in  another direction.

The spool valve has one-inlet two outlets and two exhaust. The two outlets are connected to the inputs and output of the cylinder via two flow control valve. The flow control valve maintains the regular flow of the air in the cylinder.

WORKING
    
  The valve is connected to the cylinder ( Ref. To fig. PICCIR/001/01 ) at normally open condition. The cylinders piston is in retracting stroke (i.e.) the outlet(2) of spool valve is connected to input i1. the outlet(4) is connected to the input i2 of the cylinders(c1, c2). For cylinder (c3) the connection is in reverse order. When no current is given the airflow from the outlet (2)to the input i1 to make the piston at retraction stroke. The air other side of the piston is exhausted out to the atmosphere via i2 and exhaust(5). When the current is applied the air will flow from the outlet(4) to the input i2 to make the piston at exhausted stroke and the air at other side exhausted out to the atmosphere via i1, and exhaust 3. The spool valve is controlled externally with the help of the electronic circuit.

PNEUMATIC CIRCUIT