MENG 4019 - Practical 4 – 2022
Task: design and simulate the operation of a hydraulic curcuit. Two hydraulic cylinders:
First hydraulic cylinder: stroke 2000 mm, D piston 100 mm, d rod 50 mm angled 75 degrees from horizontal is lifting a mass load of 500 kg. Pulll external force 8000 N, push external force 10000 N.
Second cylinder: stroke 1000 mm, D piston 100 mm, d rod 50 mm. Pulll external force 10000 N, push external force 15000 N.
Sequence:
First cylinder extends, command by a push button.
Once first cylinder reaches limit of stroke, after 3 seconds, the second cylinder extends.
After the second cylinder reaches limit of stroke, and after 4 more seconds, first cylinder retracts, then second cylinder retracts
Use PLC to control the sequence
First, we build the conceptual circuit:
1. Open Automation studio, select and insert the following components from the Hydraulic set of components.
2. Edit the valve – change the internal distribution
Then copy/paste the valve: select and ctrl + drag it
3. Connect circuit as shown below. You can name the cylinders:
4. Set the parameters for the hydraulic cylinders
5. Check the circuit - Select the Simulation tab and run a Normal Simulation. Then, Stop Simulation and run a Slow-Motion Simulation. Click on the valves to change position. Check that all connections are set and are correct:
6. Set the PLC for the control of the circuit. From the Ladder for Allen-Bradley PLC/ Ladder for AB PLC drag a Rung in the model:
7. We see that the surface of the sheet is too small. Right click on the document, select Document Properties and change the size to A3:
8. Click on the rung and move it in a suitable position. Then from Electrical Control (JIC Standard), from PLC cards, select and place the PLC Input Card and PLC Output Card, as shown:
9. From the Electrical Control (JIC Standard) insert the power supply in the PLC input and output cards. Insert the push button and call it START.
10. Set the solenoid for Cylinder 1 in the output bank (SOL_1), an Examine if Closed (XIC) contact and an OTE (Output Energise). Link them: XIC to the IN0 input, the OTE to the OUT0 output, the SOL_1 to the valve’s solenoid and the solenoid between OUT0 and the power supply:
11. We check that the rung operates correctly and the cylinder 1 is correctly being actuated with the push button
12. We seal-in the solenoid as the push button is pressed. We use a program instruction reference between the output and the input:
13. We check if it works – all seems correct:
14. We also insert a push button – STOP – connected to IN1 and an Examine if open (XIO) contact in the first rung
15. We check the START/STOP functionality – all seems correct
16. We set the proximity sensor on the first cylinder, we insert a normally open proximity switch, and we connect it to IN2, we insert an XIC contact into the next free rung and a timer. We set the timer at 3 seconds (time base 0.1 s, preset counter – 30)
17. We connect the Done output of the timer to an XIC input and the OTE to the second solenoid
18. We check functionality. All seems to be working well:
19. We need to set the proximity sensor on the second cylinder, link it to a normally open proximity switch, link the proximity switch in the input, link it to an XIC and a timer in the PLC.
If the number of rungs is insufficient, click on the last rung and pull it down gently
Connect all components, add two XIO contacts before the B3:0/0 and OUT2.
Note: ensure the connections are with the DN of the second timer – check code of the timer
20. Check the functionality of the circuit. All seems to be in order.
Save the circuit, then try alternatives. Add functionality and test. Document your work.