EIGHT CYLINDER HYDRAULIC SYSTEM CONTROL
Some machines are driven by a hydraulic system made up of a pump, a main valve plus secondary valves whose job is to move the machine's cylinders. In this problem we are going to control an eight cylinder machine. We will focus on just the secondary valves which will be of the double effect type. The operator will control the up and down movements of the cylinders with a cable pendant, The UP and DOWN push buttons are pulse signals while C1 through C8 are level signals. In order to operate the machine he must first choose the upwards or downwards direction by pressing and inmediately releasing the UP or DOWN push buttons. Then he must proceed by selecting the cylinder he needs to work with by pressing one of the eight buttons C1 to C8. As long as he keeps the button pressed down the cylinder will move but it will come to a stop as soon as it is released. For safety reasons there is also an E-Stop and a RESET push buttons. As per EN 60204-1 Safety of Machinery, the push buttons to ...