Hydraulic circuit simulation exercises
Exercises and observations
Directional Valve Symbol Experiments
1. Select Free>1_Simple Cylinder Control, from the drop-down list.
♦ Click on the blue circles to activate the valve and observe its perfomance.
♦ Click on the directional valve to open the DCV Setup box.
♦ Click the top drop down box menu to select and change the valve's centre condition.
♦ Experiment with the different centre conditions to observe their effect on the pump and actuator operating conditions.
♦ Change the pump from fixed to variable displacement and then experiment with the different valve centre conditions again.
2. Select Directional>4_2way 2posn Valve, from the drop-down list.
♦ Operate the directional valve and observe how switches the flow.
3. Select Directional>5_3way 2posn Valve, from the drop-down list.
♦ Operate the directional valve and observe how switches the flow.
Consider1: Directional valve centre conditions will affect the load and therefore the input power required by the pump.
Question 1: What centre condition requires the lowest power input power with a fixed displacement pump?
Consider2: Spool valves will always have a small amount of leakage between ports.
Question 2: What is the key difference to the cylinder lines between having all ports closed, in the centre condition, and A + B to tank?