More and more people modify the wheel hub to explain the wheel hub test project

【The owner's family car knowledge】The importance of wheels to cars is the same as the importance of legs to people. With the development of automobile culture, more and more people will include wheel modification in their modification list. At the same time, many merchants have also seen the business opportunities of wheel modification and launched a large number of modified wheels in the after-sales market. However, due to the lack of relevant domestic quality standards, the wheel market lacks corresponding supervision, and various fake and unmarked wheels appear in the Auto parts city and modification shop.

In fact, in the wheel manufacturing industry, the quality inspection of wheels is very strict. Under normal circumstances, if a wheel is to enter the supply system of an automobile manufacturer and become the original wheel of a certain car, it needs to pass more than 40 tests before it is possible. Through the preliminary screening, the wheels in the after-market or modified market have to go through more than 10 tests and certifications before they can be put on the market... And the above are only limited to formal manufacturers, while domestic small factories rely on the imitation ability and low cost of appearance. The price of ”has taken a lot of the market, but for us, it is a big problem to buy a good-looking and safe wheel from the market, because it is difficult to distinguish the quality of the wheel from the appearance.

【The owner's family car knowledge】The importance of wheels to cars is the same as the importance of legs to people. With the development of automobile culture, more and more people will include wheel modification in their modification list. At the same time, many merchants have also seen the business opportunities of wheel modification and launched a large number of modified wheels in the after-sales market. However, due to the lack of relevant domestic quality standards, the wheel market lacks corresponding supervision, and various fake and unmarked wheels appear in the Auto parts city and modification shop.

In fact, in the wheel manufacturing industry, the quality inspection of wheels is very strict. Under normal circumstances, if a wheel is to enter the supply system of an automobile manufacturer and become the original wheel of a certain car, it needs to pass more than 40 tests before it is possible. Through the preliminary screening, the wheels in the after-market or modified market have to go through more than 10 tests and certifications before they can be put on the market... And the above are only limited to formal manufacturers, while domestic small factories rely on the imitation ability and low cost of appearance. The price of ”has taken a lot of the market, but for us, it is a big problem to buy a good-looking and safe wheel from the market, because it is difficult to distinguish the quality of the wheel from the appearance.

Therefore, we decided to select and purchase several samples from the market, and take these samples to a certified third-party laboratory to conduct standard quality inspections on these wheels, and use the data to understand how the quality of the wheel products on the market is. ? But before the launch of this test article, our article will briefly introduce the manufacturing process and test standards of the wheel from the technical point of view, so that you can have a general understanding of the standards and test technology of our selection of products.

●Those things about wheels

First of all, we should first talk about the structure of the wheel hub, which is mainly composed of rims and spokes. The rim is what we commonly call the rim, which is used to match the tire assembly and support the tire. As for the spokes, the simplest understanding is the banner that supports the rim, and all the hubs are composed of these parts.

Material selection and production process

According to the material, the wheels are mainly divided into steel wheels and light alloy wheels. Among them, the light alloy wheels are mainly made of aluminum alloy and magnesium alloy products. At present, steel wheels are rare in China's automobile market, and most models use aluminum alloy wheels, that is, light alloy wheels.

The aluminum alloy materials used in the manufacture of aluminum wheels are all A356. A356 aluminum alloy is mainly composed of aluminum, silicon, magnesium, iron, copper, manganese, zinc, titanium and other metal elements, of which aluminum accounts for about 95%. A356 type aluminum has the characteristics of small specific gravity and good corrosion resistance, so the aluminum used in all cast aluminum wheels is A356. Moreover, the A356 aluminum materials currently used in China are all primary aluminum, and secondary aluminum is rarely used.

Casting is a more commonly used production process now. Its production process is to liquefy the alloy solid and pour it into a mold and then cool it and solidify it.

●Several technologies for manufacturing wheels

Gravity casting

The casting production process is divided into gravity casting and low pressure casting. Gravity casting mainly relies on the gravity of the aluminum water itself to pour into the mold cavity, and the pressure in the flow comes from the weight of the aluminum water itself. Gravity casting is the most primitive casting tool with low technical content, so it is mostly manual. The level of craftsmanship is difficult to guarantee.

Low pressure casting

Low pressure casting means that the molten aluminum enters the mold under pressure, and the molten aluminum undergoes solidification and crystallization under pressure. The entire process is mechanized, so the level of technology is very stable. In terms of production costs, the cost of low-pressure casting is greater than that of gravity casting, but due to the need for mass production, automakers now specify the use of low-pressure casting products to ensure product quality.

As can be seen from the schematic diagram, compressed air is used to let the molten aluminum enter the mold, and then continue to pressurize until the molten aluminum is cooled and shaped in the mold. In this process, the air pressure and various parameters are controlled by the computer, so the yield rate is very high, which meets the requirements of mass production, but this does not mean that there will be no defects in low-pressure casting.

Speaking of this, I need to mention again, although aluminum alloy materials can allow part of the recycled aluminum to be reused, because of cost issues, few manufacturers actually do this. Most of the recycled aluminum is used where the strength requirements are not very high. Of other industrial products.

Forging technology

As for forging, it is a change from solid to solid. The wheel style is formed by means of tapping, pressing, forging, etc. This process does not undergo a liquid phase change, and it is a solid change. Therefore, its mechanical properties are higher than that of casting, and its reliability is much higher than that of cast wheels. However, the cost of forging presses required for forging aluminum alloy wheel blanks is too high, which has caused the price of forged wheels to remain high. For the same wheel, the cost of forging is several times or even ten times that of casting, so forged wheels mostly exist in high-end. Modified market.