SMW Autoblok VNK-T2 Manual De Instrucciones página 4

1. GENERAL
1.1 VNK hydraulic cylinders are the most advanced on the market as regards
speed, safety, and reliability. They have all the safety conditions required
by the international regulations.
1.2 SAFETY VALVES. VNK cylinders have two inbuilt non-return valves
which can be inspected from the outside.
They maintain the pressure in the chambers even in the case of reduction
or interruption in oil pressure. (The minimum required pressure is 5 bar.)
1.3 PRESSURE RELIEF VALVES. In each VNK cylinder chamber there is
a maximum pressure valve rated to open automatically in case of over-
pressure.
1.4 PISTON STROKE CONTROL. The rear of the cylinder is equipped with
a piston stroke control system, using proximity switches (not supplied)
or using of a linear positioning system (LPS). To use this system please
refer to the specific instruction manual.
1.5 MOUNTING WITH REAR SCREWS. The VNK cylinders can be mounted
using rear screws (drw. 4), that allow in many applications mounting of
the cylinder directly onto the pulley, therefore, much closer to the rear
bearing of the spindle.
1.6 The hydraulic rotating cylinder is packed with great care prior to
despatch and is therefore safe from any damage caused by ordinary
loading, transport and unloading.
The external metal parts are coated with suitable anticorrosion protection
which must be removed before operating the cylinder.
This is best done by a light brushing with kerosene/paraffin, followed by
the cylinder being thoroughly dried.
2. FIXING OF THE ROTATING HYDRAULIC CYLINDER TO THE
LATHE SPINDLE.
2.1 There are many different ways of mounting a rotating hydraulic cylinder
to a lathe spindle.
The fixing system chosen, with or without adapter, depends on how the
rear of the spindle itself is built. (see drw.4)
2.2 HANDLING OF THE CYLINDER
IMPORTANT: the cylinder can be handled only by using the proper
lifting device.
According to the location the cylinder will have on the machine (hori-
zontal or vertical) it will be necessary to use lifting chains, and or belts,
and or eyebolts. (see drw. 2).
n
Attention: the operator must check that:
- The belts or lifting chains are strong enough to lift the load and are in
perfect working conditions;
- The eyebolts are screwed to the bottom (see drw.1).
Drw
1
Drw
2
Z
2.3 In order to turn at high speed with minimum vibration, the cylinder
must be as close as possible to the rear bearing of the spindle and turn
perfectly centered in comparison to the machine's rotational axis. It
is therefore necessary before mounting the cylinder, to check that the
mating surface onto which the cylinder will bear, is running true to the
following precision criteria: (see drw. 3)
VNK CYLINDERS USE AND MAINTENANCE INSTRUCTION
Drw
3
Cylinder
Concentricity
Flatness
2.4 Once the precision of the adapter has been checked, assemble the
cylinder on the adaptor itself, preferably using the rear fixing screws.
First tighten the screws slightly, then center the cylinder so that the rota-
tion takes place according to the following precision criteria (see drw.4):
Drw
4
Then tighten the screws fully with the torque values in the following
table:
Screw nominal
size
M8
M10
M12
M16
M20
2.5 VNK cylinders are provided with 2 threads for connection to the draw
tube, to guarantee the best adaptation to the spinde bore. The 2 threads
are the ones marked with F1 and F2 on the drawing of page 3, and both
have a centering diameter (respectively K1 and K2). When building the
draw tube, after choosing which thread to use, provide a centering dia-
meter of 5 m in K1 or K2.
3. CYLINDER CONNECTION WITH THE DRAINING AND FEEDING
HOSES.
n
3.1 all feeding and draining hoses must be flexible. Avoid using any rigid
or semirigid tube which could exercise an axial pressure on the collector
and damage the bearings.
n
3.2 Only use connectors with parallel threads and a suitable seal washer.
NEVER USE CONNECTORS WITH TAPERED THREADS.
Z
3.3 The feeding and draining manifold (the non rotating part of the
hydraulic cylinder) must be kept in position by using a bracket anchored
on the machine (see drw. 5 , A or B). The bracket must not exert axial
pressure and must have a 2-3 mm radial clearance. Keep the oil draining
and the coolant draining piping vertical, in order to encourage discharge
(by gravity).
4
Size ≥ 200
Size ≤ 170
0,01 0,015
0,005 0,010
Class 12.9
F (KN) M (Nm)
16 23
26 45
38 77
72 190
110 370