I. Introduction The wheel hub, also known as the rim, is a cylindrical, center-mounted metal part that supports the tire's inner profile. The parameters are as shown below: Figure: Schematic representation of hub component parameters Second, classified by material The hubs are mainly classified into steel hubs and light alloy wheels according to the materials, while light alloy wheels are mainly made of aluminum alloy and magnesium alloy products. In today's automotive market, steel wheels are rare, and most models use aluminum alloy wheels, light alloy wheels. Figure: AEZ Wheel (Aluminum Alloy) Aluminum alloy materials used in the manufacture of aluminum hubs include A356, 6061, and the like. Among them, A356 has been selected for a large number of cast aluminum wheels. A356 aluminum alloy has the characteristics of small specific gravity and good corrosion resistance, mainly composed of aluminum, silicon, magnesium, iron, manganese, zinc, copper, titanium and other metal elements. Aluminum accounts for about 92%, which is a mature aluminum alloy. material. Figure: A356 aluminum ingots for the manufacture of aluminum alloy wheels Third, aluminum alloy wheel production process Aluminum alloy wheels are more suitable for passenger cars than steel wheels. At present, the manufacturing process can be basically divided into three types. The first type is casting. Most auto manufacturers now choose to use casting technology. The second is forging, which is mostly used in high-end sports cars, high-performance cars and high-end conversion markets. The third type is rather special. It is the MAT spinning technology first introduced by Japan's Enkei Company. At present, the application of this technology in China is not as good as the first two. 1. Gravity casting Gravity casting is simple, mainly relying on the gravity of aluminum water to fill the mold, which is an earlier method of casting. Figure: Wheel Gravity Casting Schematic The method has low cost, simple process and high production efficiency. However, during the casting process, inclusions are easily entangled in the castings, and gas may sometimes be trapped to form porosity defects. Wheels produced by gravity casting are prone to shrinkage and shrinkage and have poor internal quality. In addition, restrictions on the fluidity of aluminum fluids may also result in low wheel yields for complex shapes. Therefore, automotive hub manufacturing has rarely used this technology. 2. Low-pressure casting method Low-pressure casting is a process in which aluminum liquid is charged into a mold under pressure, and solidification and crystallization are performed under pressure. In the same situation, compared with gravity casting, the internal structure of the low-pressure casting hub is denser and stronger. In addition, low-pressure casting utilizes pressure filling and replenishment, which greatly simplifies the structure of the pouring system and enables the liquid metal recovery rate to reach 90%. At present, low-pressure casting has become the first choice for the production of aluminum wheels. Most aluminum alloy wheel manufacturers in China use this technology for production. However, the low-pressure casting method also has its disadvantages: long casting time, long time for feeding, changing molds, and investment in equipment. Hub Low Pressure Casting Schematic 3. Forging method Hot forging→RM forging→Cold spinning→Heat treatment→Machine work→Shot blast→Surface finishing Forging is a change from solid to solid, and the hub pattern is formed by means of slap, press, forge, etc. This process does not occur in the liquid phase and is a solid change. Therefore, its mechanical properties are higher than that of casting, and it has the advantages of high strength, good corrosion resistance, and precise dimensions. Grain flow direction is consistent with the direction of force, so strength, toughness and fatigue strength are significantly better than cast aluminum wheels. At the same time, the typical elongation of a forged aluminum hub is 12% to 17%, so it can absorb road vibrations and stress well. In addition, the surface of the forged aluminum hub is non-porous, so it has a very good surface treatment capability. However, the biggest drawback of forged aluminum hubs is the large number of production processes and the production costs are much higher than that of the cast. Although the performance of forged wheels is better, automakers still use casting wheels in most vehicles. Only a few luxury cars are equipped with forged wheels. However, CITIC Decker, a leading domestic hub manufacturing company, has successfully entered the passenger car forged hub production line and reduced the cost of forged wheels to RMB 1,000, and has already started to supply domestic joint ventures as the original hub. 4. Squeeze casting method Figure: Schematic diagram of hub extrusion casting process 5. Special molding: MAT spinning technology MAT spinning technology was first put into use by Japan's Enkei company. Strictly speaking, it should be considered as a kind of casting. It refers to the use of special equipment to rotate and pressurize the bearing after the rim is cast. The internal molecular arrangement of the metal in the treated position is changed, and the specific split surface exhibits a higher density of fibers than a general cast product, thereby changing the overall metal mechanics process method. The mass, strength and extensibility of the hub manufactured by MAT spinning technology are close to those of forged wheels, and are now easier for forged wheels. In general, the MAT spinning technology can relatively ensure the manufacturing cost of the hub, and at the same time, it can also make the cast hub create similar weight and strength to the forged hub. Only the domestic technology is immature and the cost is high, so the application is not much. Picture: Enkei Racing Revolution Series RS05RR Wheels with MAT Spinning Technology Fourth, famous wheel brand 1.RAYS (Japan-Korea Department) Japan's famous hub manufacturers, the products produced are typical Japanese wheels, almost all Japanese models can find the corresponding parameters of the modified wheels. Japanese and Korean wheel hub brands are also abundant. Similar brands to RAYS include WORK, ADVAN, ENKEI, and BuddyClub. 2.BBS (Germany) Headquartered in Germany, original supplier of BMW, Audi, Porsche, Volkswagen, Mercedes-Benz, Land Rover and other auto brands; Ferrari and Maserati sports car hub suppliers. 3.OZ ​​(Europe and the United States) The famous wheel manufacturers in Italy provide a variety of wheel products to the major car brands including Volkswagen, Mercedes Benz, Jaguar, Alfa Romeo, Ford, Lotus, Suzuki, etc., which make OZ a household name. It sponsors and supports a variety of international auto races such as the F1 Drivers Grand Prix. 4.TWG (The Wheel Group·European and American Department) One of the largest dealers of automotive modified wheels in the United States, headquartered in Los Angeles, USA. Its 12 brands include the high-end luxury series Baccarat, Mazzi, Veloche, and Touren, as well as Ion, Akita, DIP, Sacchi, Detroit, MPW, Ridler, and Mayhem, which are positioned in the mid-market. The product sizes cover all passenger car needs. 5. CITIC Daica (Homemade) The leading brand of domestic wheels – the world’s largest supplier of aluminum wheels and aluminum chassis parts; the domestic auto parts industry’s export volume; the annual output of aluminum wheels reached 35 million, and there is one aluminum wheel per second. Supports 8 million vehicles worldwide. The exit signs category features lighted LED exit signs to comply with building fire codes and insurance standards. These energy-saving, illuminated, long-life LED exit signs to use less than 5 watts of power, lowering your energy consumption and saving you money every month. An exit sign is a device in a public facility (such as a building, aircraft, or boat) denoting the location of the closest emergency exit in case of fire or another emergency. Most relevant codes (fire, building, health, or safety) require exit signs to be permanently lit.
We offer a wide range of designs and features for LED exit signs including glass exit sign, aluminum and acrylic exit sign, ABS and acrylic exit sign, and ABS exit sign.
Commercial Exit Sign,Illuminated Exit Signs,Battery Powered Exit Signs,Emergency Exit Lights Led Jiangmen City Pengjiang District Qihui Lighting Electrical Appliances Co., Ltd , https://www.qihuilights.com
Squeeze casting, also known as liquid forging, is a process that combines the characteristics of casting and forging - pouring a quantity of metal liquid directly into an open metal mold and applying a certain pressure on the liquid metal through a punch. , to make it filled, shaped and crystallized, and to produce a certain amount of plastic deformation during the crystallization process. Advantages: Smooth mold filling, the metal is crystallized and solidified directly under pressure, so the casting will not produce casting defects such as pores, shrinkage holes and shrinkage, etc., and the structure is dense, the mechanical performance is higher than that of the low pressure casting parts and the investment is much lower than the low pressure casting method. Disadvantages: Like traditional forged products, milling operations are required to complete the spokes. In Japan, a considerable number of automotive aluminum wheels are produced using the squeeze casting process. The entire process from pouring the molten metal to removing the casting is controlled by a computer, and the degree of automation is very high. At present, all countries in the world use squeeze casting as one of the directions for the production of automobile aluminum wheels. 
