Chapter 16 Carpet and InsulatorComponent ViewCarpet Dash sound insulation Assy. Dash heat insulation panelInterior & Exterior Trim and Accessory -Carpet and Insulator6-391. Removal
a. Remove front rear seat, left front doorsill, right front doorsill, right center lower pillar lower trim, left center
pillar lower trim, right rear doorsill shield, left rear doorsill shield, frontal and rear parts of auxiliary fascia
console;
b. Remove the sound insulator assembly under carpet and dash, the dash heat insulation (in compartment).
2. Mounting
a. Mount accelerator pedal assembly, brake and clutch pedal assembly, brake assembly onto the car;
b. Install the carpet according to the corresponding holes with its left and right edges mounted separately under
the left front doorsill shield, the right front doorsill shield, the right center pillar lower trim, the left center
pillar lower trim, right rear doorsill shield and the left rear doorsill shield.
Fig. 5-7 Luggage Compartment Main
Cover Assembly
1. Luggage compartment main cover
2. Rear seat hook mounting plate assembly
3. Left/right side angle plate
4. Drip channelII. Movable Plate Work(1) Engine Hood & Front Fender The engine hood is used to protect the engine and fit the vehicle design. It is also helpful to the repair and
maintenance, and isolates the engine's noise. The engine hood has a double-lock device. The unlocking function
of the first locking is controlled by the cable handle under the instrument board. The unlocking function of the
second locking can raise the hood to a certain height. The double-lock function is designed in consideration of
safety. Especially when the vehicle is running at a high speed, it can prevent the engine hood from being raised,
which may cause traffic accident. The maximum angle at which the engine hood opens is 65°(See Fig.5-8).Fig. 5-7 Engine Hood & Front Fender
1. Engine hood
2. Hinge pin
3. Hinge support
4. Hinge
5.Inner hood panelSurvey -Body Structure7-642
3
51Max. opening angle less
than 65°compartment together with the rear floor and side walls. As shown in Fig. 5-7, a torsion resistant frame is also
formed at the rear part at the same time.3
4
213 2
II. General Repair Principle1. Precaution
(a) Vehicle Protection
In the welding process, make sure to protect the paint, windshield,
seat and carpet with heat-resistant and fireproof covering.
(b) Safety Measures
(1)When pulling the body or crossbeam with drawing device, do
not stand at the position in the same line of the drawing cable,
and make sure to use safe drawing cable.
(2)Before repairing, make sure to check whether there is any
leakage. In case of any hole, remove it immediately.
(3)When welding near to the oil tank, make sure to remove the
oil tank first, and block the oil pipe.
(c) Protective Article
In the repairing process, make sure to wear uniforms, helmet and
safety shoes. In addition, according to the different work types,
wear proper gloves, welding mask, goggle, earplug, face cover,
and dust respirator etc. Wear the protective devices properly as
the table below.Body Repair -Body Damage Forms and requirements For Repair7-11Seat covering Windshield
coveringWrongWrongItem
Dust Respirator
Mask
Goggles
Safety Shoes
Welded Goggle
Earplug
Welded Mask
Welded Gloves Code
A
B
C
D
E
F
G
H
Section 3 Repair After Body Damage The body damage repair includes rectification, reshaping, reinforcing, local change, and complete replacement.
Generally, CO2 welding method is used.I Reshaping Repair1. Rectification
In general, the deformation of body is caused by accident. It can be rectified in a supporting method. In the
rectification process, apply the force in the direction against the force of accident or deformation. In most cases,
cold rectification can be used. Local heating can reduce internal stress, and the corresponding processing shall be
carried out.
For the limousine, it is preferred to rectify it with the dressing machine. All dimensions and tolerances of all
parts shall be returned to the original standard, so the mobility, serviceability and comfortableness can be
guaranteed. (Fig.5-23)Section 2 Typical Technique of Body Panel RepairFig. 5-23 Mounting Bench of Universal Dressing Machine7-16Repair Process Flow:Visual Inspection
& AppraisalRemove Remove Paint Appraise
Platework
RepairAssemble PaintBody Repair -Typical Technique of Body Panel Repair/ Repair After Body Damage
The body repair starts from the primary rectification or rough rectification. The deformation can be removed
with the supporting method. The angle of the supporting force shall be close to the angle of the external force that
caused the damage. Apply a counterforce at the back of the pulling force point to adjust the supporting force. Make
measurement on the deformation generated in the supporting process. To remove the internal stress, heat the
corresponding parts. For different rectification methods, see Fig. 5-24.
2. Reinforcement
When the local damage, rupture or crack occurs on various components, repair can be made by reinforcement.
Especially for those parts on which damage occurs frequently, special reinforcement measures shall be taken.
However, random reinforcement or component welding shall be avoided, which may affect the body's status.
The reinforcement includes bushing reinforcement, patching reinforcement, arc inlay, and angle plate reinforcement.
3. Local Removal & New Parts Replacement
For the parts with serious corrosion, they must be removed. For the ruptured parts, they shall be replaced
entirely. For the posts manufactured with thin plate by punch, they shall be ordered from the manufacturer. When
the molding is made independently, all specifications (including material, section dimensions and thickness etc.)
shall meet the original design requirement. For the ruptured post (including cross beam), if it is replaced entirely,
it must be connected in the same manner as that of the original post.II. Repair for Body Outside Plate1. Damage Type
a. Crack & Rupture
In the running process, the body vibrates continuously and burdens the loads. When the vehicle makes accident
acceleration, sharp swerve an emergency brake, the body will keep in an inertial status. When the vehicle runs on
the uneven road, bend and distortion will happen on the body.
Affected by these external forces for a long time, crack and rupture may occurs on the stress concentrated parts
and weak structure on the body outside plate.
The stress mostly concentrate on the corner, hem and narrow part of the outside plate, so crack and rupture often
occur on these parts.
b. Corrosion
The corrosion on the outside plate is mostly caused by the mud and water on the metal surface. Only in special
case, it results from the chemical corrosion by chemicals. When the corrosion occurs, rust may appear on the
outside plate and fall gradually, resulting in a hole. On the skirt outside plate and launder, corrosion usually occurs
on the seams between door and frame and the interlayer between the outside plate and the frame.
c. Cave-inFig. 5-24(a) Drawing Rectification Fig. 5-24(b) Drawing & Supporting
RectificationFig. 5-24(c) Auxiliary Force-receiving
Point Rectification7-17washerBody Repair -Repair After Body Damage
(f). Flatten the edge with hammer or sizing block, and remove the burr with file to make sure that it is aligned
with the both side alternative plates with a clearance not more than 1mm;
(g). Replace the plate, and clamp it with pincers. Carry out the spot welding along the seam at a space of
approximately 50mm;
(h). Make the welding from the center to both sides alternately block by block. Which can reduce the
deformation;
(i). Strike the welding line with the hammer or sizing block to remove the retaining stress. Polish the welding
lien wit the file or manual grinding wheel to make it even and smooth for the painting.
c. Repair for Accidented Damage
(a). Plate work flattening
When the accidented damage occurs on the plate work of the body, it can be repaired by means of beating.
In the repair process, start from Point C as shown in Fig. 5-26. Put the sizing block on the convex point, and beat
it with the hammer and change the block's position correspondingly. When the convex point is flattened, the
concaved part in Point B will rise. Similar wit the original profile of the plate, for the remaining dent, a sizing block
with the same radian can be employed. Press the bottom of the plate with hand, and beat the high point of the dent
with the hammer. (Fig. 5-27)Fig. 5-27 Plate Work Flattening (II)
A. Hammer B. Plate work
C. Sizing block Fig. 5-26 Plate Work Flattening (I)
A. Impact point B. Concaved point after impact
C. Convex point after impactFig. 5-28 Heating & Planishing
Convex Point
1. Heating pointBody Repair -Repair After Body Damage7-19 In the beating process, beat the work piece heavily at the beginning and lightly at the end. Attention shall
be paid to reduce the number of beating as possible as it can. Don't beat the same points repeatedly to prevent the
metal plate extending locally, which can complicate the repair work.
For the larger arc concave, a sizing block can be used under the center of the concave. The area of the sizing
block shall be a little larger. Jack the concaved plate up with a supporting tool. Sometime, heat the concaved part
to wine color to reduce the force. When jacking the plate up, a little excess is acceptable. (Fig. 5-28)
(b) Thermal contraction
When the concave is jacked up, if the plate extends seriously and the area is large, the thermal contraction
method can be used in case that the traditional methods don't work. (Fig. 5-29)
Heat the work piece to cerise color with oxyacetylene flame. The heating scope depends on the degree of extension.
If the extension is serious or the area is large, the heating point shall be larger relatively (diameter: approx.20-
30mm). If the extension is not serious or the area is small, the heating point shall be a little smaller (diameter:
approx.10-15mm). After the heating, beat the heating point immediately. In the beating process, a proper sizing
block is used under the plate. After it is cooled down, beat it lightly with the hammer.
The contraction starts from the highest point to the center, and then to the edge. Heat and flatten the extended
part repeatedly till the plate is flattened fully. If the convex part is too high, compress it to one half of the original
height. After it is cooled down, heat it at the original heating point till the other half of convex part is removed.
Fig. 5-29 Thermal Contraction Method For those parts that are not sure whether they will contract or not, the thermal contraction method shall not
be used to avoiding any side effect. Especially for those thin plates, great attention shall be made to prevent them
from melting down or burning through.
(c) Welding ring
The welding ring method is used to repair the most seriously damaged part of the concave on the plate work
surface. Some rings are welded to connect the rods. (Shown as Fig. 11-30) When the area of the concave is large,
several rings can be welded in a parallel manner, and gets through the rod to make the pulling force act on the plate
surface evenly. The ring can be replaced by the washer. The rod pulls the washer or shaft through a coupling device.
After the concaved plate is flattened by the inertia hammer puller, remove the ring or washer and finish the welding
points.Fig. 5-30 Welding Washer StretchingBody Repair -Repair After Body Damage7-20Washer WasherHeating
Compress
loadCooling
Extend load Plate work
thermal contraction Metal bar thermal
contractionWasherShaft
Shaft Shaft Rod
2. Shock Absorption & Noise Isolation
(1) Body structure (Fig. 5-37)
a. Arrange the reinforced bar reasonably to improve the parts' rigidity, reduce the shock and lower the noise.
b. Apply the sealant in the floor seam to improve the floor sealing and reduce the noise in the cabin.Fig. 5-37 Front Wall Panel
1. Front wall bridge reinforced panel
2. Front wall mid-frame panel
3. Front wall lower main panel
4. Heat-isolated pad
Fig. 5-38 (a) Body floor
1. Front mud guard 2. Rear side wall 3. Rear wheel housing 4.Floor sides (2) Deadening
It is an interactive and systemic work to make the body isolate heat, shock and noise. Besides the measures
carried out to improve the body's stiffness and sealing performance, the following measures shall be taken in the
design and manufacture process.
a. Sound isolation material: add sound isolation pad on the front wall and floor.
b. Sound absorption material: add molded carpet on the front floor and rear floor.
3. Sealing
Special consideration has been given to the sealing of the body both in design process and in manufactureprocess. Sealing plays an important role in many aspects, such as dust resistance, water resistance, corrosionresistance, heat resistance, heat preservation, and noise reduce etc. Especially when the body floor and front wall
stay in a tough external condition, the mud, dust, noises (from the tire and engine) and hot air will invade into the
cabin any time.
After the body assembly is welded, sealant will be employed on all joints to prevent the water and steam
penetrating into the metal seam and ensure the quality of subsequent painting.
In addition, a thick layer of impact-proof PVC coat is applied on the base of the body, which has excellentsealing performance. For the sealing to those assemblies, the traditional sealing method is used, such as rubber sealBody Repair -Features and Composition of Automobile Body7-251
123Front4