1. Front cross beam assembly
The front cross beam assembly includes front cross beam left/right support assembly, front cross beam sub-
assembly, front cross beam side support etc. They play a role in front bumper.
2. Left/right longitudinal beam assembly
The left/right longitudinal beam assembly includes left/right longitudinal bean front and mid- block assembly,
energy-absorbing beam big assembly, and left/right front damper support assembly etc.
It is mainly used to install engine left/right suspension, left/right front suspension damper, storage battery and
other accessories. In the outside, it can be equipped with left/right front fender.
3. Radiator cross beam assembly
The radiator cross beam assembly includes radiator left/right post big assembly, radiator lower cross beam big
assembly, radiator central support sub-assembly, and radiator upper cross beam big assembly etc.
It is mainly used to install radiator, condenser, engine hood lock, radiator hood, front bumper, and front
headlight.
4. Front wall lower plate assembly
The front wall lower plate connects to the floor, which separates the engine compartment from the cabin. It
includes front wall frame assembly, front wall lower main plate assembly, brake installation reinforced plate, and
front wall left/right support assembly etc.Fig. 5-2 Engine Compartment Assembly & Front Wall Parts
1. Front cross beam assembly 2. Left/right longitudinal beam assembly
3. Panel left/right support assembly 4. Front wall lower plate sub-assembly 5. Front wall upper assembly
6 Radiator cross beam assemblySurvey -Body Structure7-2123456front wall lower plate assembly, front wall upper assembly, left/right front damper support lower front plate
assembly, and right front damper right-angle support assembly.
The cave-in is mainly caused by collision and extrusion. For the light cave-in damage, the metal doesn't extend,
which is plastic deformation. If the collision or extrusion is serious, the metal plate will rupture. For the vehicles
running in the city, it is common that collision damage occurs on the side wall.
d. Bend & Distortion
Bend and distortion belong to mechanical damage. Bend and distortion may have a variety of causes, such as
collision or extrusion, alternating loads generated by the vibration, accident acceleration, emergency brake, sharp
swerve and body torsion caused by poor road.
For the light distortion, it shall be confirmed by test. For the serious bend and distortion, it is obvious in the
appearance. Generally, the distortion can be fixed according to the clearance of the frames and the change of their
relative positions.
e. Unsoldering
The unsoldering is caused by the poor fusion between different metal plates.
2. Outside Plate Repair
a. Repair for Crack
(a) CO2 Welding
The crack on the metal outside plate can be repaired by CO2 welding. In the welding process, align the two
metal plates, and weld the outside crack of the plate first. If the crack doesn't exceed 50mm, the welding shall start
from the rear part of the crack and continue along the crack and edge. If the crack is a little longer, several points
shall be welded first at a certain space. After welding several points, finish them and then weld the crack block
by block. By so doing, it can prevent the metal overroasting and plate deformation caused by too high temperature.
If the crack is located in the position that burden heavy force and it is convenient to carry out the welding operation,
a double-welding method can be used. After the spot welding is made outside, carry out the welding inside. After
the inside welding is completed, make the welding outside in the same manner.
After the welding, put a sizing block inside, and beat from the outside welding line with hammer to removeFig. 5-25 Concave Body Filling Repair b. Repair for Local Damage
For the local corrosion or serious mechanical damage on the outside plate, if it can't be repaired in common
method, the patching or pasting repair method can be used.
Repair Method:
(a). Fix the patching scope;
(b). Cut the paper sample;
(c). Cut the plate as per the sample;
(d). Adhere the molded plate on the surface of the patching part;
(e). Line out the profile along the plate edge with needlepoint, and cut off the damaged or corroded part;Body Repair -Repair After Body Damage7-18the retaining stress. Finally, finish the welding
seam properly to make it even and smooth for
painting.
(b) Solder Filling
For the fine concavo-convex plate with
damage and crack on its surface, it can be re-
paired with a solder filling method. (Fig. 5-25)
