Dacia SuperNova (engine E7J). Service manual - part 84

40

GENERAL

40 - 4

OPENINGS CLEARANCE

40

GENERAL

40 - 5

The replacement (reparation) operations of the weldable elements described in this

chapter are specified subject to: cutting out of the parts to be replaced; the access to the
welded elements, tools and checking devices accessibility, etc.

In case the vehicle body has suffered important deformations it is recommended the

straightening of the damaged body elements, by means of some hydraulic presses, the
operation being performed slowly and at cold.

For this range of vehicles, the elements resistance structure which are affecting the

vehicle security, are not to be partially replaced ( not to be cut), but entirely.

After welding detaching, the body elements must remain straight, without breakage or

cracks, the possible holes being covered out with filling material or by tinning. The body
elements surfaces are to be pickled ( to eliminate possible oxidation marks) , dried and
initially applied a paint layer.

The electric welding detaching of the body elements, is performed as follows:

- with a well sharpen chisel, this method may lead to parts deformation or even

parts breaking.

- by using some extractors equipped with steel cutter type Brendeo or Pickvant

max. 6 mm, having the cutting head as per shape shown in pict.1.

1. Centering point
2. Sharpen slope
3. Drill acting edges
4. Gap for catching the welding material

P = aprox. 0.4 mm

Whatever method is used, the remaining element must be in good order and to allow

performing of a good quality welding point.

The plates cutting it is recommended to be performed ( subject of importance and thick-

ness ) using manual scissors or pneumatic portable tools for plates cutting.

During cutting or welding of the body elements it is necessary to protect the electric

wiring from the interior of the body structure.

The cutting, welding, or strengthening operation done on body welded elements, are to

be performed on body checking/ straightening bench type CELETTE .

IMPORTANT

When removing or straightening the body resistance elements it is forbidden the

total or partial heating, in order to avoid the mechanical resistance and metal elasticity
decreasing.

 REPAIRING GENERAL CONDITIONS

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GENERAL

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WELDING TYPES AND PARAMETERS

At the reparation of the welded body elements, three welding categories may be used:

protection gas welding (CO2), electric spot welding and filling materials welding
(autogenous).

At the autogenous welding, it is recommended that flame must be slightly inclined so

that arch can be seen and the flame extremity to be maintained at aprox. 5 mm from the
part to be welded.

1. Spot welding resistive parameters for steel plates with carbon content C < 0,15 %.

Plate thickness  (mm)   Welding current  (KA)   Welding time  (per)   Tightening force   (

daNm.)

0,5                                6,5                                 5

                          130

0,8                                8,0                                 8

                          200

1,0                                9,5                               10

                          250

1,25                            10,5                               10

                          295

1,5                              10,0                               14

                          310

2,0                              12,0                               16

                          350

NOTE
1 period = 1/50 part of a second

2. Welding parameters for the welding in protector gas for carbon steel plates or low-
alloyed steel.

Horizontal welding position ( pict.1)

Plate thickness   (mm)

0,6

1,0

1,5

2,0

Electrode diameter  (mm)

0,6   0,8

0,8      1,0

0,8   1,0

0,8   1,0

Welding wire speed (m/min)

2,5   1,9

3,2   2,4

4,4   3,8

5,7   4,4

Welding current  (A)

35   35

55   80

80   120

100   130

Welding speed  (m/min)

0,25   0,25

0,35   0,33

0,33   0,50

0,45   0,45

Welding voltage  (V)

17   17

18   18

19   19

20   20

Protection gas flow (1/min)

12 - 17

Electrode free length (mm)

 6 - 12

plates welding

in tiers

end to end

welding

corner

welding

0-1,5mm

0-1,5mm

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GENERAL

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 WELDING TYPES AND PARAMETERS

NOTE
In case of using the Ar + CO2 mixture, the welding voltage will decrease with 2 V.

Vertical welding position ( obligatory from top to bottom) pict. 2

Plate thickness

0,6

12

2,0

Electrode diameter (mm)

0,6   0,8

0,8   1,0

0,8   1,0

Welding wire speed (m/min)

2,5   1,9

3,3   3,2

5,7   4,4

Welding current (A)

35   35

70   100

100   130

Welding speed (m/min)

0,25   0,25

0,38   0,48

0,50   0,50

Welding voltage (V)

17   17

18   18

20   20

Protection gas flow (1/min)

12 - 17

Electrode free length (mm)

 6 - 12