Specifications

Series CU
Actuator Precautions 1
Be sure to read before handling.
1. There is a danger of sudden or erratic action
by cylinders if sliding parts of machinery are
twisted and changes in forces occur.
In such cases, bodily injury may occur, e.g., by catching hands
or feet in the machinery, or damage to the machinery itself may
occur. Therefore, the machinery should be adjusted to operate
smoothly and designed to prevent such dangers.
2. A protective cover is recommended to mini-
mize the risk of personal injury.
If a driven object and moving parts of a cylinder pose a serious
danger of bodily injury, design the structure to avoid contact
with the human body.
3. Securely tighten all stationary parts and
connected parts so that they will not become
loose.
Especially when a cylinder operates with high frequency or is
installed where there is a lot of vibration, ensure that all parts
remain secure.
4. A deceleration circuit or shock absorber may
be required.
When a driven object is operated at high speed or the load is
heavy, a cylinder’s cushion will not be sufficient to absorb the
impact. Install a deceleration circuit to reduce the speed before
cushioning, or install an external shock absorber to relieve the
impact. In this case, the rigidity of the machinery should also be
examined.
5. Take into account a possible drop in operat-
ing pressure due to a power outage.
When a cylinder is used as a clamping mechanism, there is a
danger of work pieces dropping if there is a decrease in
clamping force due to a drop in circuit pressure caused by a
power outage. Therefore, safety equipment should be installed
to prevent damage to machinery and bodily injury. Suspension
mechanisms and lifting devices also require drop prevention
measures.
6. Take into account a possible loss of power
source.
Measures should be taken to protect against bodily injury and
equipment damage in the event that there is a loss of power to
equipment controlled by air pressure, electricity, or hydraulics.
7. Design circuitry to prevent sudden lurching
of driven objects.
Take special care when a cylinder is operated by an exhaust
center type directional control valve or when it is starting up
after residual pressure is exhausted from the circuit. The piston
and its driven object will lurch at high speed if pressure is
applied to one side of the cylinder because of the absence of
air pressure inside the cylinder. Therefore, equipment should
be selected and circuits designed to prevent sudden lurching
because of the danger of bodily injury, particularly to limbs,
and/or damage to equipment when this occurs.
8. Take into account emergency stops.
Design the system so that bodily injury and/or damage to
machinery and equipment will not occur when machinery is
stopped by a manual emergency stop or a safety device
triggered by abnormal conditions.
1. Confirm the specifications.
The products featured in this catalog are designed for use in
industrial compressed air systems. If the products are used in
conditions where pressure and/or temperature are outside the
range of specifications, damage and/or malfunctions may
occur. Do not use in these conditions. (Refer to specifications.)
Consult with SMC if fluid other than compressed air to be used.
2. Intermediate stops
When intermediate stopping of a cylinder piston is performed
with a 3-position closed center type directional control valve, it
is difficult to achieve stopping positions as accurately and
precisely as with hydraulic pressure due to the compressibility
of air.
Furthermore, since valves and cylinders are not guaranteed for
zero air leakage, it may not be possible to hold a stopped
position for an extended period of time. Contact SMC in case it
is necessary to hold a stopped position for an extended period.
Selection
Design
1. Operate within the limits of the maximum
usable stroke.
The piston rod will be damaged if operated beyond the maxi-
mum stroke. Operate within the standard stroke range.
2. Operate the piston in such a way that collision
damage will not occur at the stroke end.
3. Use a speed controller to adjust the cylinder
drive speed, gradually increasing from a low
speed to the desired speed setting.
Warning
Warning
Caution
Design
Warning
9. Consider the action when operation is re-
started after an emergency stop or an abnor-
mal stop.
Design machinery so that bodily injury or equipment damage
will not occur upon restart of operation.
When the cylinder has to be reset at the starting position, install
safe manual control equipment.
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