Brochure

2000
1500
1000
500
400
300
200
100
2 3 4 5 10 20 50
m2 max. m1 max.
MY1B40
Horizontal collision: P = 0.5 MPa
m3 max.
Air cushion
H unit
L unit
2000
1500
1000
500
400
300
200
100
12345 10 20 30
m2 max. m1 max.
MY1B32
Horizontal collision: P = 0.5 MPa
m3 max.
40 50
H unit
L unit
Load weight kg
Load weight kg
Absorption Capacity of Air Cushion and Stroke Adjustment Units
Collision speed mm/sCollision speed mm/s
Load weight kg
2000
1500
1000
500
400
300
200
100
12345102030
m2·m3 max. m1 max.
MY1B25
Horizontal collision: P = 0.5 MPa
40
Air cushion
H unit
L unit
Collision speed mm/s
Air cushion
Cushion Capacity
Cushion Selection
<Air cushion>
Air cushions are a standard feature on mechani-
cally jointed rodless cylinders.
The air cushion mechanism is incorporated to
prevent excessive impact of the piston with high
kinetic energy at the stroke end. The purpose of
air cushion, thus, is not to decelerate the piston
near the stroke end.
The ranges of load and speed that air cushions
can absorb are within the air cushion limit lines
shown in the graphs.
<Stroke adjustment unit with shock absorber>
Use this unit when operating with a load and
speed exceeding the air cushion limit line, or
when cushioning is required outside of the
effective air cushion stroke range due to stroke
adjustment.
L unit
Use this unit when cushioning is necessary
outside of the effective air cushion range even if
the load and speed are within the air cushion
limit line, or when the cylinder is operated in a
load and speed range above the air cushion
limit line and below the L unit limit line.
H unit
Use this unit when the cylinder is operated in a
load and speed range above the L unit limit line
and below the H unit limit line.
<Fastening of unit>
The unit can be secured by evenly tightening
the four unit holding bolts.
<Stroke adjustment with adjustment bolt>
Loosen the adjustment bolt lock nut, and adjust
the stroke from the lock plate side using a
hexagon wrench. Retighten the lock nut.
<Stroke adjustment with shock absorber>
Loosen the two lock plate holding bolts, turn the
shock absorber and adjust the stroke. Then,
uniformly tighten the lock plate holding bolts to
secure the shock absorber.
Take care not to over-tighten the holding bolts.
(Refer to the “Tightening Torque for Stroke Ad-
justment Unit Lock Plate Holding Bolts.”)
(Note)
Although the lock plate may slightly bend due to
tightening of the lock plate holding bolt, this
does not a affect the shock absorber and lock-
ing function.
3. Refer to the below figure when using the
adjustment bolt to perform stroke adjustment.
When the effective stroke of the shock ab-
sorber decreases as a result of stroke adjust-
ment, the absorption capacity decreases dra-
matically. Secure the adjustment bolt at the
position where it protrudes approximately 0.5
mm from the shock absorber.
4. Do not use a shock absorber together
with air cushion.
Tightening Torque for Stroke Adjustment
Unit Holding Bolts
Unit: N·m
Bore size [mm]
25
32
40
Unit
A
L
H
A
L
H
A
L
H
Tightening torque
3.5
5.8
13.8
Tightening Torque for Stroke Adjustment
Unit Lock Plate Holding Bolts
Bore size [mm]
25
32
40
Unit
L
H
L
H
L
H
Tightening torque
1.2
3.3
3.3
10
3.3
10
Calculation of Absorbed Energy for Stroke
Adjustment Unit with Shock Absorber
Unit: N·m
Unit: N·m
Horizontal
collision
Vertical collision
(Downward)
Vertical collision
(Upward)
Type of
impact
Kinetic energy
E1
Thrust energy
E2
Absorbed energy
E
F·s F·s + m·g·s F·s – m·g·s
E1 + E2
Symbols
υ: Speed of impact object [m/s]
F: Cylinder thrust [N]
s: Shock absorber stroke [m]
m: Weight of impact object [kg]
g: Gravitational acceleration [9.8 m/s
2
]
Note) The speed of the impact object is measured
at the time of impact with the shock absorber.
Caution
1. Use caution not to get your hands
caught in the unit.
s When using a product with stroke adjustment
unit, the space between the slide table (slider)
and the stroke adjustment unit becomes
narrow at the stroke end, causing a danger of
hands getting caught. Install a protective cover
to prevent direct contact with the human body.
2. Do not operate with the stroke adjustment
unit fixed in an intermediate position.
When the stroke adjustment unit is fixed in an
intermediate position, slippage can occur de-
pending on the amount of energy released at
the time of an impact. In such cases, the use
of the holder mounting brackets for adjust-
ment, available per made-to-order “-X416”
and “-X417”, is recommended.
For other lengths, please consult with SMC.
(Refer to the “Tightening Torque for Stroke
Adjustment Unit Holding Bolts.”)
υ
m
s
s
υ
m
s
υ
m
Air Cushion Stroke
Unit: mm
Bore size [mm]
25
32
40
Cushion stroke
15
19
24
m·υ
2
1
2
Lock plate
holding bolt
Unit holding bolt
Adjustment bolt
lock nut
Shock absorber
Lock plate
Adjustment bolt
Shock absorber
0.5
Series MY1B
8