ROBO Cylinder GR3LM, Инструкция по эксплуатации, Страница: 42 / 128

1. Specifications Check
36
(2) Moment generated on the fingers due to an external force
External force as well as gripping force will be applied to the work piece and the finger attachment in
the movements such as moving straight or turning in the condition of the gripper being attached on a
Cartesian Robot, Articulated Robot or other actuators.
Have the following calculation.
♦ External force applied on the work piece and finger attachment [F
X
, F
Y
, F
Z
]
Figure out the following types of external forces in three directions, X, Y and Z, applied on the work
piece and finger attachment considering the condition of the gripper use, and sum up all the values to
determine F
X
, F
Y
and F
Z
.
a) Weight of the work piece and finger attachment
F = mg m : mass of the work piece and finger attachment [kg],
g : gravitational acceleration [=9.8m/s
2
]
b) Inertial force in the gripper moving straight
F = ma a : Acceleration/deceleration during transportation [m/s
2
]
c) Centrifugal force in gripper turning
F = mr ω
2
r : Radius of turning [m], ω : Angular velocity [deg/s]
Confirm that F
z
is below the allowable load vertical direction, F
zmax
in Table 1.
♦ Moment generated on the fingers due to an external force
Figure out the moment in each direction due to external forces F
X
, F
Y
and F
Z
calculated above.
1) Moment in Ma direction [M
oa
]
M
oa
= L
c
F
X
× 10
-3
2) Moment in Mb direction [M
ob
]
M
ob
= H
c
F
X
× 10
-3
3) Moment in Mc direction [M
oc
]
M
oc
= L
c
F
Y
× 10
-3
+ H
c
F
Z
× 10
-3
(3) All moments in each direction generated to the fingers
• Two-finger type
M
a
= M
Ia
+ M
oa
, M
b
= M
Ib
+ M
ob
, M
c
= M
oc
• Three-finger type
M
a
= M
Ia
+ M
oa
, M
b
= M
ob
, M
c
= M
oc
Confirm that the value figured out in the calculation above is below the allowable moment stated in
Table 1.
(Note) Select finger attachments that are as small and light as possible within the allowable ranges. If
the fingers are long and large or heavy, moments may generate due to impact upon gripping of
the work part and consequently the actuator performance may drop or guide may be negatively
affected.