Hydraulic Press-Meter in Question The cylinder of a hydraulic press has to exert a forward thrust of 10 kN during the fast approach stroke, a thrust of 100 kN during the pressing stroke and a reverse thrust of 10 kN. The effects of using various methods of regulating the extend speed will be considered. The retract speed should be approximately 5 m/min utilizing full pump flow. Assume that the maximum pump pressure is 160 bar and the pressure drops over the following components and their associated pipe work (where they are used): Filter = 3 bar Directional control valve (DCV) = 2 bar Flow-control valve (controlled flow) = 10 bar Flow-control valve (check valve) = 3 bar Determine the following: (a) The cylinder size (assume the piston-to-rod area ratio to be 2:1). (b) Pump size. (c) Circuit efficiency (indicating the pump and load power)when during: Case 1: Fast extension approach stroke: (using full pump flow, the flow control valve is fully opened). Case 2: Pressing stroke while the Meter-in flow control is activated for extend speed 0.5 m/min. • Case 3: Retraction stroke. (d) The time required to complete a cycle of extension and retraction, knowing that the fast approach stroke is 255 mm and the pressing stroke is 25 mm (e) The number of pressed workpieces in a shift of 12 hours, if the time to change the workpiece is 23.64 sec, (f) The electric energy consumed by the pump over a shift, the heat accumulated over a shift (g) The electric cost of operating this hydraulic press for a month (24/7) for an electricity tariff of SR 0.25/kWh (h) The size of the cooling unit required to cool the oil to keep its temperature constant. (i) Assuming that for some reasons, the extension speed was to be limited to 0.5 m/min while the extension load is only 5 kN, what would be the pressure in the piston and rod sides within the cylinder and what is required to handle such a situation 3 bar 10 bar Ap -160 bar -- -0 U Extended load 100 kN Ap 3 har Retract load 10 kN Ap - 2 bar Hydraulic cylinder with meter-in anton' Assume that the overall efficiency of the along with its electric motor is 72 %. (i) Assuming that for some reasons, the extension speed was to be limited to 0.5 m/min while the extension load is only 5 kN, what would be the pressure in the piston and rod sides within the cylinder and what is required to handle such a situation Recommended cylinder bore and rod size standard BS5785: 1980 Piston Dia 40 50 (mm) 63 80 100 80 125 140 160 180 200 220 20 250 Rod Dia 20 28 36 45 56 70 90 100 110 125 OFF 140 669 160 small (mm) Large 28 36 45 56 70 90 100 100 110 125 140 160 180