First, surface damage, mainly wheel hub surface wear and scratches.
The second kind, deformation damage, as the name implies, is that the hub is deformed and twisted under the action of external force.
Third, fracture damage, when the hub is strongly impacted, the hub breaks in different degrees.
Combined with the actual maintenance process, let's take a look. ...
How to repair these three kinds of injuries?
Is each repair method reasonable?
First, surface damage repair.
Common wheel hub injuries are mainly abrasions and abrasions, and the repair only deals with the surface, which basically does not affect the main stress structure of the original wheel hub, and has little impact on the reliability and safety of the wheel hub.
The repair process is simple and the technology is mature.
The repair steps are as follows:
Step one, sandblasting:
First of all, the surface of the hub should be roughly polished before repair, and the stubborn dirt on the hub should be cleaned up by sandblasting process, and at the same time, the adhesion of the hub surface before painting should be enhanced.
Step 2, polishing:
Most of the wheel hubs are treated with dust-free sand blasting, and then the details are polished with more delicate water sandpaper. This part belongs to meticulous work, and patience is very important.
Step 3, putty filling:
It is easy to understand how to fill the scratches with alloy putty after the wheel hub is polished and leveled, which is the same as that in automotive sheet metal.
The difference is that alloy putty is used on the wheel hub, which is harder and more delicate than ordinary putty used in automotive sheet metal.
Fourthly, aluminum welding and filling:
If the gap at the rim of the wheel hub is obvious and cannot be filled with putty, the gap can only be filled with aluminum welding.
Of course, in order to ensure the reliability of the hub, not all gaps can be filled by welding, provided that the hub is not deformed, the gap cannot be too large and the edge cannot be cracked.
Step 5, polishing:
After filling, use an angle grinder to grind the excess unevenness.
What needs to be explained here is that although the hub is also welded and filled, it is different from welding after the hub is broken.
First of all, the notch position is mainly distributed on the edge of the hub, not on the main stress structure of the hub.
Secondly, the aluminum welding filling process can only be carried out under the condition that the hub cannot be deformed and cracked.
Step 6, professional painting:
After the surface treatment, it's time to paint.
This step is the most technical step in the process of wheel hub surface repair, and each merchant has its own unique experience and technology.
(Unfortunately, the whole process of paint mixing, painting and baking is not allowed to be filmed and watched. )
Step 7, lathe programming:
The traditional grinding method can't be used for the wheel hub whose surface is brushed by metal. Precision machining requires the use of a professional CNC lathe, and the master needs to measure the irregular radian of the surface, and then program the measured data into the CNC lathe.
Step 8, CNC wire drawing:
After the programming work is completed, the lathe cuts the surface according to the setting of a knife until all scratches disappear.
It is worth mentioning that this step will change the thickness of the hub. It is recommended not to repair more than twice. Excessive repair will make the bearing surface of the hub thinner, which will have an impact on the overall structure.
Step 9, nano metal protective paint:
After the previous process is completed, the hub is sprayed with a layer of nano-metal protective varnish, which is similar to the bright paint sprayed by ordinary car body panels.
The difference is that the nano-metal protective paint has higher hardness than ordinary varnish and is not easy to wear after baking by the merchant's unique baking process.
Step 10, fine polishing:
The repair process of the hub is basically over. In order to make the wheel hub look more brand-new and beautiful, the polishing machine is started with coarse and fine abrasives to finish the wheel hub polishing. In a short time, a perfectly repaired wheel hub was completed!
Comparison before and after maintenance:
Before and after maintenance
The repair of wheel hub surface scratches is common, and the repair technology of wheel hub surface scratches that can be seen in the market is similar.
The difference lies in the fine-tuning of paint color and baking process.
Through the observation of the whole surface repair process, the process is still rigorous, and the effect after repair is almost close to the original factory.
The key is that compared with buying new wheels, cost performance is its advantage.
Second, the deformation repair:
Under normal circumstances, the hub can be deformed, mostly due to careless driving and the impact of strong external force on the hub.
Although the merchant has the means to repair the deformed hub in good condition, we do not recommend the owner to repair it. Why?
Let's see how the deformation is corrected first.
Step 1, deformation position detection.
First, find the position where the hub is deformed. The master installed the hub on the self-made fixture, and used the dial indicator to find the deformed position for calibration.
Step 2, heating:
Heat the deformed part locally with a blowtorch. The little red dot on the wheel hub is an infrared thermometer, which can stop heating when it reaches a certain temperature.
Step 3, correct:
After reaching a certain temperature, the hub becomes soft and fine-tuned repeatedly with small hydraulic pressure. Finally, reach a reasonable standard.
Step 4, complete:
The whole process seems to have no problem, but the problem has already appeared!
As we know, the wheel hub is made of aluminum alloy, and its metal has poor fatigue resistance. After being deformed by external force, it is forcibly restored to its original state by external force. Even if there are tiny cracks on the surface, from a scientific point of view, the metal structure here is completely different from the normal hub.
What followed was an unpredictable fatigue crack somewhere, and then a terrible fracture.
Therefore, if you find that the hub is deformed, don't think about repairing it. Replacing the wheel hub with a new one is the only way.
The third type: the wheel hub is broken.
According to some advertisements or articles, the wheel hub fracture can be repaired by welding.
Although the broken parts can be welded together, the hub is not reliable at this time.
As we know, the normal wheel hub manufacturing process is casting. Is the metal in the molten state, under the pressure of cooling or crystallization.
Welding is a process of local heating, melting and solidification.
Therefore, there must be welding stress around the weld. After a period of loading operation, fatigue cracks are likely to occur in the high stress area of the hub, which may cause serious consequences if not found in time.
Hub fracture can be said to be the most serious kind of hub damage.
Therefore, don't try to repair the damaged hub. It is very dangerous to continue to use the repaired hub.
Summary:
To sum up, wheel hub repair is not omnipotent, and not all damages can be repaired.
Except for the surface renovation, the other two kinds of damage are not recommended to be repaired.
Thirdly, the role of the hub is not only for beauty, but also for life safety.
Take the hub seriously, don't lose too much because of small.
There are a lot of wheels, things you don't know.
Author: rear view RearVision
In the modern sense, the hub also refers to all parts of the wheel except the tire, including the rim, spokes and accessories.
As early as the end of 19 and the beginning of the 20th century, automobile wheels began to appear. Rim, hub and spokes are an integral and inseparable casting process. The first appearance is thick and simple steel wheels with single color.
This production technology was quite advanced at that time, so basically cars used this kind of steel ring.
When the single steel wheel hub was widely used for a long time, people looked at the cars coming and going on the road, and the wheels were all the same. Everyone has a small mind and wants to highlight his unique and high-grade taste among all sentient beings.
But before shaping your distinctive personality, you should understand these striking things.
wood tissue
As mentioned above, steel wheels first appeared.
The wheel hub is heavy and the shape is poor, which can be summarized in one word-ugly.
It also has the disadvantages of easy rusting and poor heat dissipation, but it also has the advantages of low cost, impact resistance, high strength and strong bearing capacity.
Endured the "eye-catching" of steel wheels for a long time, and finally an integrally cast aluminum alloy wheel hub appeared at 1958.
The aluminum alloy hub improves the face value of the hub and reduces the weight of the hub. It can be said that the limelight is strong, and aluminum alloy wheels occupy a dominant position in the market.
The aluminum alloy wheel hub is made of low-density aluminum alloy. It has the advantages of light weight, various shapes, beautiful appearance and good heat dissipation performance, but it also has the disadvantages of poor impact resistance and high cost.
Of course, if you are not satisfied with aluminum alloy, you can also choose magnesium alloy wheels.
Magnesium alloy is the lightest structural material used at present. Light weight, good mechanical properties, has been used in batches in the field of vehicles.
With the reduction of the price of magnesium raw materials and the improvement of anti-corrosion technology, the original problems of high price and easy corrosion of magnesium alloy wheels have been improved. However, the price is still about twice as high as that of aluminum alloy, so the owner who wants to choose should be carefully considered.
It's all made of metal. Why doesn't it feel high enough?
Then I recommend the fighter in the hub material-carbon fiber hub.
The use of carbon fiber can effectively reduce the weight, which is beneficial to the start, stop and steering of vehicles. When the weight of the hub is reduced, the rotational energy will be reduced, which can make the driver's operation response faster, that is, the control effect is better.