hydraulic subtopic

2.  Based on :
◦ Understanding the problem by considering type
and quantity of components
◦ Number of process*
* Each process is represented by one cylinder
(actuator)

3.  Understand the problem step by step:
◦ Identify type of cylinder
◦ Identify the right control valve for selected
cylinder
◦ Identify methods to start the operation
◦ Identify methods to stop the operation
◦ Identify other parameters (if needed)

4. SINGLE ACTUATOR
CIRCUITS

6.  Actuated directly via mechanical valve, without
intermediate switching
 Limits: 1) Piston diameter < 40 mm
2) Valve with connection size < 1/4”
 If not mentioned, use indirect control
 Example:
A single cylinder of 25 mm in diameter is to clamp a
component when a push button is pressed. As push
button is activated, the cylinder is to remain in the
clamp position. If the push button is released, the
clamp is to retract.

7.  Solution:
◦ Identify type of cylinder
 Single acting with spring return
◦ Identify right control valve for selected cylinder
 3/2 way valve (for single acting)
◦ Identify methods to start the operation
 Push button (3/2 way with spring)
◦ Identify methods to stop the operation
 Push button (release the start button)
◦ Identify others parameter (if needed)
 NIL

9.  Used when the force should prove too high for
manual actuation of valve (for large piston diameter)
Signal is generated via smaller valve
 Example:
A single cylinder with a large piston diameter, is to
clamp a workpiece following actuation of a push
button. The cylinder is retract once the push button
is released.

11.  Solution:
◦ Identify type of cylinder
 Single acting with spring return
◦ Identify right control valve for selected cylinder
 3/2 way valve (for single acting)
◦ Identify methods to start the operation
 Push button (3/2 way with spring) activate
control valve
◦ Identify methods to stop the operation
 Push button (release the start button)
◦ Identify others parameter (if needed)
 NIL

14.  Example
◦ A double acting cylinder is to advance if one of two
push buttons is operated. If the push button is
released, the cylinder is to retract.

17.  Example
◦ The piston rod of DAC is to advance when the 3/2-
way roller lever valve AND the push button of 3/2-
way valve are actuated. If either of these are
released, then the cylinder will return to its initial
position.

20.  Example
◦ Clamping of a drilling machine starts when one of
two push buttons is pressed and it is released
when the third push button is pressed.
◦ Parameters
 There is no clamping if the workpiece is not in the
position.
 Clamping device cannot be opened during the
drilling in operation.
 Clamping process must be performed slowly.
 Clamp opening must be performed rapidly.

21. F=0
4 2
5
1
3
1 1
2
1 1
2
2
1 3
WS
2
1 3
2
1 3
1 1
2
2
1 3
2
1 3
DS
F=0
2
1 3
DS
WS
35%
1
2
3
Start A Start B
St op Drill Sensor
Workpiece Sensor
DRILL M/C
CLAMP M/C