Speed Control; Cushion; Directional Control - SMC Networks C96N C Series Operation Manual

2-5. Speed control

1) When the piston speed is adjusted, install SMC AS series speed controller near the air supply port to
adjust to the specified speed.
2) Use speed controllers to adjust the speed. There are two types of speed controllers for adjusting the
speed: one is to regulate the supplied air into the cylinder (meter-in control), and another is to regulate the
exhausted air from the cylinder (meter-out control). As the cylinder operation may be unstable with the
meter-in control type speed controller, the meter-out control type speed controller is generally used for
double acting cylinders.
C a u t i o n
Piston speed should be controlled gradually from low speed with a speed controller fully closed to the
specified speed.

2-6. Cushion

C a u t i o n
・ Cylinder cushions are adjusted properly before shipping, re-adjust the cushion valve on the cover
according to the load and the operating speed.
・By turning the cushion needle in clockwise direction, air is restricted more and the cushion's effectiveness
is improved. When the cushion valve is turned counter-clockwise, the restriction becomes larger and the
cushion's effectiveness is decreased.
・If the cushion valve is fully closed, the piston may bounce at the stroke end, not move through the full
stroke, or the cushion seal may be damaged due to excessive pressure. Do not use the cushion valve in
this way.
・Activate the air cushion when operating the cylinder. If this is not done, the piston rod assembly or the
tie-rods will be damaged when the allowable kinetic energy exceeds the values shown in Graph 8 (page 7).
W a r n i n g
・
Do not open the cushion valve beyond the number of allowable rotation .
Although, it is crimped as a cushion valve retention mechanism, do not open the cushion valve beyond the
number of the allowable rotation. If the cushion valve is opened beyond the number of the allowable
rotation, it will come out from the cover when air is supplied.
The allowable rotation is the number of rotations from a fully closed state of the restrictor of the cushion
valve to a fully opened state.
・
Ensure to use an air cushion at cylinder stroke end.
If the screw tightening and untightening torque exceed allowable torque, the valve will be broken when
fully closed, or the screw meshing will come over the retention mechanism and the valve will come out
when fully opened.
Table2 Cushion valve
Bore size (mm) With across flats
32,40
50,63
80,100
・Use the air cushion at the end of cylinder stroke.
Activate the air cushion when operating the cylinder. If this is not done, the piston rod assembly or the
tie-rods will be damaged when the allowable kinetic energy exceeds the values shown in Graph 8 (page 7).

2-7. Directional control

To switch the operating direction of the cylinder, mount an applicable solenoid valve selected from
SMC's range of solenoid valves.
！
W a r n i n g
・Design a circuit to prevent sudden action of a driven object.
When the product is actuated by an exhaust center type directional control valve or when one side of the
piston is pressurized with air exhaust, such as when the product is started after the exhaust of the residual
pressure from the circuit, driven objects may act suddenly at high speed. In such cases, injury may occur,
such as hands or feet getting caught in the machinery, or damage to the machinery itself may occur.
Hexagon wrench
JIS 4648 Hexagon
2
wrench key 2
JIS 4648 Hexagon
2
wrench key 2
JIS 4648 Hexagon
3
wrench key 3
No. of allowable rotation
4 turns
4.5 turns
5.5 turns
- 13 -
Allowable torque
0.02N・m
0.02N・m
0.06N・m