Chery S11 / Chery QQ. Manual — part 162

Chery QQ Maintenance Manual Body System

dimensions between sheet metal parts of all kinds, inspect concrete location of damage, make
clear the type of damage, analyze cause of damage, determine maintenance plan.

2.1.3 Main content of door maintenance
Generally speaking, cause of door damage has something to do with the following four aspects:
defect in structural design, defect during the process of production, chemical damage while being
used, physical damage while being used. Main damage causes are introduced as follows:
1. Abrasive wear. Caused by surface friction produced by relative movement because of sheet
metal parts surface touch together and being weighted; for example, door is hanging down,
coordination gap is enlarged because of long time abrasive wear between door hinge hole and
spindle.
2. Corrosion
Oxidizing reaction of sludge-liquid and filth accumulated on surface of the metal; or rust
produced by not adopting preservative treatment after welding repair or corrosion resulted by
touching chemical substance. It occurs frequently in sandwich position and spot welding article
joint .
3 Fissure or rupture
Fissure and rupture when it is serious, caused by sheet metal fatigue in the position of stress
concentration and weak link of structure because sheet metal suffers from internal and external
stress repeatedly.
4 The hollowness and fold damage.
The hollowness means that deformation of elasticity or plasticity because of collision and forcing
of door panel.

5 The crooked and twisted damage. That kind of damage means crooked or twisted damage
because the door undertakes too much burden.

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Chery QQ Maintenance Manual Body System

2.2 Basic method of door maintenance

In view of above-mentioned damage type, main methods of doors and lids maintenance

include sinking trim、 flame straightening 、 weld、 repair by embedding

2.2.1 Trimming the rough and uneven surface
You should correct the structural casting first then correct the crease or the hollowness of outside
door panel if the rough and uneven surface of outside door panel is indirect damage because of
structural casting damage or stiffening rib damage. You can carry out initial rough repair with
hammer, beam pad or jimmy 、punch if you can touch the back of metal plank, you can carry out
repair by means of slip hammer and peen hammer if it is difficult for you to touch the back or the
metal plank is sealed.
The common rough and uneven surface trimming methods are introduced as follows:
(1)Trimming the hollowness with beam pad and hammer. It is the most common method to
knock the metal plank with hammer and beam pad.The two sides of metal plank which is to be
trimmed must be applicable to hand holding beam pad.There are two operating methods to take
the beam pad as supporter for hammer:
1) Knock on the beam pad with hammer. This method is applicable to the shaping to relative
small and shallow hollowness and crease. You can knock the protruding from right side. The
knock will result in metal plank contraction and make the metal plank to be smoothened
gradually.

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2)Not knocking the beam pad with hammer. This method means put the beam pad under the

Chery QQ Maintenance Manual Body System

lowest place of the hollowness, knock the nearby place with hammer.
Generally speaking, while trimming the hollowness with hammer and beam pad ,the protruding
side shall be knocked by the hammer, the other side shall be gasket ,you can make rough shaping
with wooden hammer then make fine trimming with iron hammer.(see figure 7).In the case of
hollowness with much bigger area, beam pad shall be put in the more shallow position of the
hollowness, the hammer shall knock the much higher position of the protruding, iron hammer
and wooden hammer shall be used alternately accordingly.
(2)Trim the hollowness with jimmy. jimmy can be self-made according to characteristic of the
vehicle body, they are handwork tool in common use for door maintenance. can be used to put
into the limited space of sandwich position of doors and lids ,it can prize open the hollowness,
this kind of method can be applicable to the hollowness which is not easy for spacer and hammer
to reach because of the narrow sandwich position of doors and lids, can be also used as the
spacer to make the hitting power of the hammer spread in much larger area.
(3)Trim the hollowness with puller. puller can be used to trim the shallow hollowness which is
difficult for other tools to touch upon, it is can be used inside the metal plank. There are two
operating methods of puller in common use.

One is boring method. That means to drill a small hole in the hollowness with portable electric
drill, then insert the withdrawal lever of thread summit or hook summit in the hole, draw the
hollowness slowly through inertia hammer sliding on the metal withdrawal lever and colliding
the handle repeatedly. You can drill more holes when necessary, fill and smooth the holes with
tin-lead bonding after the hollowness is flattened.

The other method is electrode welding.That means welding the stud nail or spacer on the

hollowness with special use spot welder, then pull the stud nail or spacer outwards
withpuller,until the hollowness is flattened. You can weld more nails and spacer accordingly, pull
the whole hollowness gradually. Finally, polish the welded mark and smooth it with grinder. This
kind of method avoids making holes in the metal plank; eliminate the potential corrosion of
metal.

2.2.2 Recovery of stretchable position
It happens frequently that sheet metal of the hollowness is stretched after being collided. It is not
sure that the stretchable position can be recovered completely using the correct operational
method during trimming process ,therefore, it is necessary for you to combine with heating
contraction method to achieve the goal of trimming.


(1) Heating position and flame energy.

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Chery QQ Maintenance Manual Body System

Effectiveness of flame straightening is up to heating position and flame energy, different heating
position result in different straightening effectiveness. The maximum and longest deformation
position shall be selected to be the heating position, that is to say the outside of deformation.
Different flame energy heating results in different straightening ability. The more the flame
energy, the more the heating speed, the stronger the contraction ability, the more concentrated the
heating energy , it is ok to heat the low carbon sheet metal to cherry red color （600 ~800

℃

℃）

.

(2) Heating mode
Heating mode which flame straightening method adopt in common use in vehicle body
maintenance include:
1) Point -like heating, it means that heating area is the circle-like points within certain diameter
scope, generally speaking, the diameter is 15-30mm,you can heat one point or more adopting
quincunx distribution accordingly, it is often applicable to the contraction of protruding in the
middle of the panel.
2) Triangle heating, it means that heating area representing triangle shape, it happens frequently
in the deformation of strip material and panel edge.

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