(week 5) advance electro hydraulics & design1
TRANSCRIPT
Hand in assignments!
Mid term test 2 weeks from now.
Same day, time and place.
CO1, CO2 and CO3 only (hydraulics, electro-hydraulics and pneumatics)
Good luck!
Relevancy:
1. Used to build Continuous Cycle circuit.
2. Used to latch a circuit for continuous supply of electricity to a particular line.
3. Used when replacing a double solenoid valve to a single solenoid valve of a circuit, without changing the originality of the circuit function.
Memory ON (Dominant Set)
+24V
0V
ON
K1
K1
OFF
K1
• When ON is pressed, Relay coil K1 will be energized. Both relay K1 switches will close. This means, while the lamp turns on, the relay switch will continuously energize the coil. Therefore, the lamp is permanently on. Only when the OFF button is pressed, the lamp will switch off.
• To confirm that this is a Memory ON circuit, press both ON and OFF together. The lamp will still light ON.
Memory OFF (Dominant Reset)
• The function of this circuit is similar to the previous Memory ON circuit. However, please note that the OFF button is placed below the ON button, not parallel!
• To confirm that this is a Memory OFF circuit, press both ON and OFF together. The lamp will NOT light ON.
+24V
0V
ON
K1
K1
OFF
K1
Proximity -> closeness
Detect close objects without contact.
Various types:
1. Inductive sensor
2. Capacitive sensor
3. Optical sensor
More than 1 actuator
1 cylinder needs 1 valve
Tips for circuit design:
◦ Identify sequence of movement
◦ Identify limit switch/sensor status
Example: A hydraulic actuated drilling machine
contains two double acting cylinders (DACs). When the work piece is located at its position, cylinder A will clamp the work piece. Then, the drilling process starts, where the spindle is controlled by cylinder B. After completion of drilling, cylinder B will retract to the initial position, before the clamping cylinder retracts.
Sequence: A (extend) -> B (extend) -> B (retract) -> A (retract)
Identify limit switch/sensor status
A+ B+ B- A-
A1 B1 B0 A0
F=0 F=0
Cylinder A Cylinder BA 0 A 1 B 0 B 1
<= Actions
<= Sensors
Rephrasing the sequence and limit switch/sensor status
A1 B0
A+ B+ B- A-
Start B1 A0
Right side of circuit
Left side of circuit