SMW Autoblok VNK-T2 Manual De Instrucciones página 8

DISMANTLING
A. Operations to follow before removing the cylinder from the machine
a1 Reduce the pressure to about 10 bar (while the piston is moving).
a2 Push the piston to about the half of its stroke.
a3 Cut off the pressure from the circuit and remove the feeding and drain
pipes.
a4 By means of compressed air, alternatively blow into the feeding fittings
and collect the oil coming out from the other fitting.
a5 Push the piston fully back
a6 Remove the rear cover (21/1) of the coolant recovery housing
a7 Remove the stroke control disc (24) with its ring-nut (23)
a8 Remove the coolant recovery housing, unscrewing the screws (46).
lt is now possible to remove the complete unit, without influencing in any
way the adjustments of the stroke control. Be careful not to damage the
wires and the proximity switches fastened to the housing.
a9 Remove the cylinder from the machine and put it on the bench.
B. Dismanting of the piston
b1 Unscrew the two drain screws "A" and "B" and the seal below (see
drawing of page 29).
b2 Unscrew the fixing screws (47) of the front cover (2).
b3 Remove the front body (1) through the threaded holes.
b4 Remove the piston (3), beating with a plastic hammer on the rear side
of the piston rod.
At this stage, it is possible to carry out the routine maintenance.
C. If it is necessary to replace the pressure relief valves, follow the
instructions listed below:
c1 lt is possible to place only the internal component of the valve 1 3/A";
the housing is integral with the piston.
c2 Measure with a gauge the position of the plug of the pre-loaded spring
with regard to the edge of the housing.
c3 Unscrew the plug. (Caution: the plug is fastened with loctite).
c4 Take out the valve and replace with new components, inserting them in
the same position as the previous ones.
c5 Screw the plug in, as deep as before, and put some loctite to fix it
properly.
The positioning of the plug is very important, because it gives the pre-
load of the spring, controlling the opening of the valve.
D. lf it is necessary to replace the safety valves, with the cylinder on
the machine follow the instructions listed below.
d1 Look for the 4 holes with plugs located on the outer surface of the cylin-
der: a small one and a larger one (see sect. E-E).
d2 Remove the 4 plugs (16) e (17) (see drawing).
d3 Insert a rod into the smaller hole.
d4 Gently push the rod unit the valve comes out from the larger hole.
d5 Check the direction of the valve in the hole.
d6 Place the new valve in the same position as the previous one.
d7 Insert and screw the plugs.
E. Dismantling of the hydraulic feeding manifold: to be made only in
the case of proved damage to the bearings.
This is a very difficult operation, which should be carried out by qualified
personnel and with special equipment.
If possible, send the cylinder to a SMW-Autoblok service centre, if not,
proceed as follows:
e1 Remove the cover (6).
e2 Remove support washer (8), by removing screws (43). Using an extrac-
tor remove the oil manifold unit (5+10+11/B+12/B).
e3 Remove washer (19).
e4 Remove the front bearing (29) using a special "L" shaped tool, which
has to be put between front cover (7) and the bearing itself. There are 2
grooves which should make it easier for the tool to get inside the cover.
e5 It should not be necessary to dismantle the unit 5+10+11/B+12/B.
Should it be necessary, remove screw (9) (there are 1 or 2, according to
the size) and remove ring (5) from the external housing (10).
DISMANTLING AND REASSEMBLY OF VNK CYLINDER
A. Reassembly of the piston (3)
a1
a2
Caution:
antirotation pins), in order to locate them in their seats in the body.
B. Reassembly of the front body (1)
b1 After greasing and mounting the seal (30) in its seat, insert the body (1)
b2 Carefully center the front cover (2) as regards the body (1).
b3 Fully tighten the screws (47).
Reassembly of the manifold ring (5 + 10)
C.
c1
c2
c3
c4
c5
D. Assembly of the cylinder onto the machine
d1 Following the assembly instructions, center the cylinder body as regards
d2 lf the manifold ring (5) - (8) has been removed, center the stop washer
E. Assembly of the coolant recovery housing and the piston stroke
control
e1
e2
e3
8
REASSEMBLY
Insert the seals:
(31) – (32) – (33) and (36)
in their seat, greasing them with a suitable product.
Mount the piston rod in its seat (2)
Beating on the draw tube end by means of a plastic hammer.
correctly position the pressure relief valves (Their housing acts as
onto flange (2) and allow the assembly of the valve housings into their
seats. Slightly screw the screws (47).
Mount the plugs A and B.
Mount the front bearing (29) and washer (19) on the adaptor (2).
Put the seals (40) in their seats, mount housing (10) on ring (5) and fix it
in position with screws (9).
Mount unit (5+10) on adaptor (2). This operation requires the greatest care.
Mount the seal (35) and the support washer (8) without fully tightening
the screws (43)
Remount cover (6).
the rotation of the spindle, then, fully tighten the fixing screws.
"8" and tighten the screws (43).
Mount the housing (21), fixing it by means of the screws (46), being
careful not to damage the wires or the proximity switches.
Mount the stroke control ring (24) with its ring-nut (23).
Mount the cover (21/1).
Note: see drawing on page 29