Publicidad
Idiomas disponibles
Idiomas disponibles
6.2 ADJUSTING THE (spot-welding) PARAMETERS
The parameters that affect the diameter (section) and mechanical strength of the spot
weld are:
- Force exerted by the electrodes.
- Spot-welding current.
- Spot-welding time.
When specific experience is lacking we recommend carrying out a number of test welds
using sheet of the same thickness and quality as that of the workpiece.
6.2.1 Adjusting the force and squeeze function (pneumatic clamp only)
The squeeze function is carried out in two ways:
a) "Permanent" squeeze (adjustment of the force):
In this mode there will be no current output from the machine.
- Take the air pressure to approx. 4 bar by adjusting the pressure regulator manually
fig.B-2.
- Enter "electrode force" mode by pressing key E twice as in fig.C.
- Keep the button of the pneumatic clamp pressed in order to squeeze the
electrodes. The clamp will hold the squeeze until the button is released.
- Release the button and read the value of the force achieved.
- Increase the pressure using the regulator and repeat the squeeze until you obtain
the desired electrode force value.
b) "Rapid" squeeze:
- Pneumatic clamp ready to weld ("material" function).
- Take the air pressure to 4 bar by adjusting the pressure regulator manually fig.B-2.
- Press the button of the pneumatic clamp and release it immediately in order to
squeeze the electrodes. The clamp will keep the electrodes squeezed for the total
time setting made for the welding cycle, without any current output.
- read the value of the force achieved, enter "electrode force" mode by pressing key
E twice as in fig.C.
_____________________________________________________________________________________________________________________
WARNING! If the button is held down for too long the machine will start the
spot-welding cycle, with current output; always make a "permanent squeeze" if
you want to be sure that there is no current output!
_____________________________________________________________________________________________________________________
_____________________________________________________________________________________________________________________
WARNING!
RESIDUAL RISKS! Also in this operating mode there is a risk of crushing the
upper limbs: take all necessary precautions (see the chapter on safety).
_____________________________________________________________________________________________________________________
6.2.2. Adjusting the spot-welding current and times (FIG. C)
The spot-welding parameters are described in section 4.2.1
Spot-welding current and time are set automatically by selecting the thickness of the
sheet to be welded with key D as in fig. C and selecting the material (see section 6.3).
IMPORTANT:
If the LED corresponding to the selected thickness "flashes" this means that the
default welding current, or the initially programmed current, is insufficient to
achieve a satisfactory weld;
The spot-welding operation is deemed correct when a tensile test causes the spot-
welding core to come out of one of the two sheets.
- It is possible to customise the welding parameters within the limits set by the
manufacturer using the "STORE" procedure:
a) Connect the tool to the spot-welder using the corresponding 14-pin recognition
connecter.
b) Keep key A as in fig. C pressed for approx. 3 seconds; the display will flash and the
"PRG" LED will light up.
c) Use key A to select the parameter to be modified and select the desired value by
turning the encoder knob.
d) Repeat the operation for all the parameters that are to be modified as in fig. C-1.
e) Press the "Store" key twice to save the parameters (the display will show "done").
f) Exit programming by keeping key A pressed down.
NOTA: during programming the spot-welder is unable to supply current output.
- It is possible to reload the factory programme for a given tool, thickness and material
using the "LOAD" procedure:
g) Enter programming mode as specified in point b) of this section.
h) Press the load key twice (the display will show "done"). It is now possible to display
the factory programme.
i) Repeat points e) and f) in this section.
6.3. SETTINGS FOR THE MATERIAL AND ARM LENGTH (FIG. C)
6.3.1 Material
- Keep key E pressed for approx. 3 seconds; the display will flash and the "PRG" LED
will light up.
- Use the encoder to select the material of the sheets to be welded from the available
materials.
- Keep key E pressed for approx. 3 seconds to save the settings and exit programming.
----------------------------------------------------------------------------------------------------------------
The available materials are:
FE = low carbon content iron sheet;
StSt = stainless steel sheet;
FE zn = low carbon content iron sheet treated with surface galvanisation.
FEHss = high yielding iron sheet
"FREE" = additional available material if present
ATTENTION! In the "FREE" programs all the values that can be adjusted, are set to
the minimum value out of default.
if you recall the default program by means of the above described LOAD function
it means to reset the program!
----------------------------------------------------------------------------------------------------------------
6.3.2 Arm length (for pneumatic clamp only).
- Keep key E pressed for approx. 3 seconds; the display will flash and the "PRG" LED
will light up.
- Use key E to select "L" ARMS.
- Use the encoder to select the length of the arms mounted on the pneumatic clamp.
- Keep key E pressed for approx. 3 seconds to save the settings and exit programming.
IMPORTANT: it is absolutely essential to select the correct arm length in order to
obtain a correct reading for the force applied to the electrodes of the pneumatic
clamp.
6.4 SPOT-WELDING PROCEDURE
Operations that are valid for all tools:
- Selecting the material to be welded (see 6.3.1).
- Selecting the material thickness (key D as in
- Displaying the preset spot-welding parameters (key A in fig.C).
- If desired, customising the spot-welding programme (see section 6.2.2).
6.4.1 PNEUMATIC CLAMP
- Select the continuous or pulsed spot-welding function (see section 4.2.1 for a
description of key "B").
- Carry out the squeeze function to adjust the force to the desired value (*).
- Place an electrode on the surface of one of the two sheets to be spot-welded.
- Press the button on the handgrip of the clamp so that:
a) The sheets close between the electrodes with the preset force (driven by the dual-
effect cylinder).
b) The spot-welding cycle starts with current passage indicated by the LED
on the control panel.
- Release the button a few moments after the LED
- At the end of the spot-weld the average welding current will be displayed (excluding
the initial and final ramps). The current value on the display may alternate with
"warning" messages as described in section 4.2.1 "display".
(*)NOTE: as the thickness to be welded increases, so do the current and electrode force
(see TAB.1). The machine display shows "LO FO" and "HI FO" for force values that are
respectively too low or too high during welding.
NOTE 1: the electrodes are replaced by releasing them using a size 14 wrench. Insert
the new electrodes and carry out a squeeze to ensure their complete insertion.
NOTE 2: the electrode-holder arms are replaced in the following way:
a) release the jaws of the arm holder with the dowel and take out the arms.
b) completely insert the new arms with sealing ring into the arm-holder.
c) then centre the locating hole with the dowel inserted into the arm-holder itself and re-
lock the jaws.
d) insert the electrodes as indicated in "NOTE 1".
___________________________________________________________________
WARNING! THE OPERATIONS DESCRIBED IN THE NOTES ABOVE MAY
CAUSE AIR TO ENTER THE HYDRAULIC CIRCUIT. PROCEED AS FOLLOWS TO
REMOVE THE AIR FROM THE CIRCUIT:
- Switch off the machine.
- Position the clamp and cables at the same level as the surface on which the
spot-welder rests.
- Restart the unit and immediately open the discharge valve (fig. B-9) by turning it
manually until water comes out.
- Close the valve immediately to prevent more water from leaking out.
___________________________________________________________________
6.4.2 MANUAL CLAMPS
- Place the bottom electrode on the sheets to be spot-welded.
- Pull the top lever on the clamp to the end of its stroke, so that:
a) The sheets close between the electrodes with the preset force.
b) The spot-welding cycle starts with current passage indicated by the LED
on the control panel.
- Only release the clamp lever a few moments after the LED has gone off (end of
welding); this delay (holding) improves the mechanical properties of the weld.
0
6.4.3 STUDDER GUN
WARNING!
- To fit or release the accessories on the studder chuck use the two fixed hexagon
wrenches to stop the chuck turning.
- When operating on doors and bonnets the earth bar MUST be connected to the
same part to prevent current passing through the hinges, and the bar must always
be set near the welding area (if the current has to travel over long distances this will
reduce the efficiency of the weld).
Connecting the earth cable:
a)
Bare the sheet as close as possible to the point where you intend to work, cleaning
an area corresponding to the contact surface of the earth bar.
b1) Fasten the copper bar to the sheet surface using an ARTICULATED CLAMP
(welding model).
Alternatively to method b1 (when practical difficulties arise) proceed as follows:
b2) Spot-weld a grommet to the prepared sheet surface; pass the grommet through the
slit in the copper bar and lock it with the supplied terminal.
Spot-welding the grommet for anchoring the earth terminal
Fit the appropriate electrode to the studder chuck (POS.9, FIG. I) and insert the
grommet (POS.13, FIG. I).
Place the grommet in the chosen area. Place the earth terminal in contact in the same
area; press the torch button to weld the grommet to be used for anchorage as described
above.
Spot-welding screws, washers, studs, rivets
Fit the appropriate electrode to the studder, insert the item to be welded and place it on
the sheet at the desired point; press the button on the studder: release the button only
*
after the preset time (LED
Spot-welding sheets from one side only
Fit the appropriate electrode to the studder chuck (POS.6, FIG. I) pressing on the
surface to be welded. Press the button on the studder and only release it after the preset
*
time (LED
goes off).
- 9 -
fig.C)
.
(
)
has gone off.
“
goes off).
4
(
)
(
)
Publicidad
Capítulos
