-29-
*If a malfunction occurs, immediately turn off the operation switch and stop the motor.
（８） ＳＭＰ−３０Ｃ、ＳＭＰ−４０Ｃ
The direction control valve has a 4-way, 3-position manual change valve (SMV-43) to operate
a double-acting cylinder.
Maintenance of pressure is possible by means of the pressure set on the pressure switch.
When the valve handle is in the middle position, hydraulic oil discharged by the pump returns to the
oil tank. Seen from the front of the pump, pressure oil exits from port A when changed to the left, and
from to port B when changed to the right.
Example of Use: To operate a double-acting cylinder:
Connect the high pressure hose and cylinder as shown in the diagram.
Assuming port A is connected to the push side and port B connected to the pull side.
1) Open the air valve.
2) Before operation, set the pressure switch to the required pressure.
3) Place the handle of the direction control valve in the middle position.
4) Turn on the operation switch to start the motor and allow it to run.
5) Move the handle of the direction control valve to the left side (port A).
The cylinder piston will advance, pressure will rise and the operation
is performed.
6) When pressure reaches the pressure set on the pressure switch the motor
will stop but pressure is maintained at that level. The motor will start again
when pressure falls to differential pressure lower than the set pressure level
set on the SPS-7A pressure switch.
7) If the pump motor is switched off during cylinder advance, both system pressure
and extension of the cylinder plunger, remain at the point reached when the motor
was stopped. On this pump the motor will not start again even if system pressure
falls.
8) When operation is completed, change the handle of the direction control valve to
the right side (port B) to release pressure then start motor to retract the cylinder
plunger.
9) Turn off the operational switch.
10) Close the air valve and return the handle of the direction control valve to the middle position
High Pressure
Hose
Port A
Pressure Switch
(SPS-7A)
Port B
Double-Acting Cylinder
SMV-43
Electrical Circuit Diagram
CR
M
CR
PS
Direction Control Valve (SMV-43)
Middle
Position
B
A
Operation Switch
(SW-4A)
ON
OFF
