Publish Time: 2023-07-05 Origin: Site
Like the automobile industry, the motorcycle industry faces severe challenges such as: energy saving and emission reduction, noise reduction, vibration reduction, improvement of safety and passenger comfort, enhancement of driving fun, and enhancement of appearance charm, etc. At present, there is little potential for improvement in design. At present, major motorcycle manufacturers often use low-density, high-quality lightweight materials to meet these challenges. Available lightweight materials include aluminum, magnesium, plastics, composite materials, etc. At present, aluminum is the lightweight material with the most practical value, because the manufacturing technology of aluminum and its parts is very mature, has the highest cost performance, and is the best material for recyclability.
1 Application of aluminum in motorcycles
In the past, motorcycles were almost always made of steel and cast iron. At present, the biggest problem facing the use of aluminum and aluminum alloys instead of steel and cast iron to manufacture motorcycle parts is the increase in cost. In motorcycle manufacturing, the engine block, cylinder head and some peripheral parts are made of aluminum alloy from the mass production of motorcycles. Since 1980, large parts such as the frame body, pedal parts, and radiators of sports motorcycles have been aluminized one after another, because these parts need to be strong, safe, reliable, light, and fast.
Japanese motorcycles are well-known all over the world. The aluminum ratio of the motorcycles they make depends on the model and use of the motorcycle, which is about 10% to 36%. In Japan, the cost control of small motorcycles is very important, and their aluminization rate is lower. For example, the aluminization rate of mountaineering, off-road, and camping motorcycles is only 10% to 15%. The aluminization rate of aggravated vehicles and non-aggravated sports vehicles running on general roads is higher, ranging from 25% to 35%. The maximum aluminization rate of heavy-duty racing cars is about 42%, which is already aluminization of all parts that can be aluminized.
2 Aluminum alloy for motorcycles
(1) Casting alloy
With the advancement of production technology and technology, all or most of the aluminum alloys are now cast aluminum alloys prepared with recycled aluminum, and the performance can be completely the same as that prepared with aluminum ingots for remelting. In addition to standard cast aluminum alloys and die-cast aluminum alloys, some companies will also develop some alloys with specific properties.
Al-Si-Cu alloys are mostly used for die-casting engine cylinder blocks or upper covers. Their usage accounts for about 5% of the total. They have good castability and pressure resistance, and are suitable for die-casting large parts. They also have high resistance Thermal, can be used for die-casting brake discs and other brake parts, has high mechanical properties and high machinability, but due to copper, corrosion resistance is not high. Their resistance and cutability are good, and they can be used in the manufacture of handlebars, pedals and brake parts that require more wear resistance.
(2) deformed alloy
Deformed aluminum alloys are not used much in motorcycle manufacturing, and forgings and pipes are used more. In order to reduce the weight of the car, replace the steel pipe welded structure with aluminum pipes, such as welding the girder with 7XXX aluminum alloy pipes, and replace steel parts with 2XXX series aluminum alloy forgings, which not only reduces the weight of the car itself, but also ensures the strength of the motorcycle.
3 Typical aluminum parts
The working environment of typical aluminum alloy engine parts of motorcycles is very harsh. Such parts include cylinders, cylinder heads, cylinder base covers, etc., which are mostly cast or forged, while pistons, camshafts, clutches, etc. are about 52% The above are produced by die-casting, gravity die-casting, and low-pressure casting processes with a high degree of freedom.
The handlebars, brake blocks, brake plates, etc. in the frame part of the motorcycle are made of aluminum alloy no matter what kind of motorcycle. In terms of functions, weighted sports cars not only require light weight and handling stability, but also have high requirements for appearance, which must be eye-catching. Therefore, the wheels, maneuverable bottom beams, rocker arms or support beams, and control pedals have all been made of high-strength deformed aluminum alloys.
(1) Piston
Motorcycle engines have two cylinders and four cylinders. The four-stroke engine is not good for the cooling and lubrication of the piston. Its maximum temperature can reach about 448°C. Even the maximum temperature of the oil-cooled four-stroke engine piston can reach 360°C. C or so. In order to increase the output power, a light-weight and thin-walled cylinder is usually used, but due to the large load stress, a high-strength aluminum alloy should be used to make the four-cylinder piston.
For the two-stroke piston, in order to reduce its thermal deformation, the material should not only be resistant to high temperature, but also wear-resistant and crack-resistant. Therefore, the hypereutectic AL-Si aluminum alloy is used for casting and surface treatment should also be carried out. Not only to maximize the power of the engine but also to minimize its noise. For this reason, the gap between the piston and the inner wall of the cylinder should be reduced as much as possible. In this case, the wear will increase. Therefore, surface treatment is necessary to prolong the service life.
(2) Cylinder
In order to ensure that the inner surface of motorcycles has high wear resistance and scratch resistance, many companies use cast iron to make the cylinder block, but the entire cylinder cannot be made of cast iron, otherwise it will hardly work normally. Therefore, most of the cylinders larger than 100CC are now made of aluminium, gravity casting or low pressure casting, and inlaid with cast iron bars. On the one hand, the weight is reduced, and on the other hand, the anti-wear performance is improved. The heat dissipation effect of the aluminum alloy cylinder is much higher than that of the cast iron cylinder, and the temperature around the combustion chamber is reduced, which improves the intake efficiency of the mixed gas, improves the impact resistance, and increases the engine output power. The voids on the surface of the body are all surface-treated to form a composite electroplating layer with a film thickness of 50-100 m, and the coating contains hard spots. The four-stroke engine cylinder is complex and large, and has cast iron inserts, most of which are die-cast. Recently, it has been manufactured by quenching powder metallurgy, which not only achieves the purpose of light weight, but also improves the performance in an all-round way.
(3) Cylinder head
The shape of the cylinder head of a motorcycle four-stroke engine is basically the same as that of a car, but because it is lightweight, thin-walled, complex in shape, and requires a stylish, bright, and ornamental appearance, casting defects are not allowed. To this end, the measures taken are: appropriately increase the temperature of the melt, enhance the fluidity, carefully design the position and shape of the runner (gate); use the computer to control various process parameters, especially the temperature distribution of each part of the model; adopt the casting performance Excellent aluminum alloy. The cylinder of a motorcycle with high output power is not only complex in shape, but also has a high thermal load, so it needs to be cast with aluminum alloy with high temperature resistance and high thermal fatigue strength.
(4) Rocking support beam
The rocker support beam is an important structural part, which is the connection between the rear wheel and the main beam. It used to be welded with steel pipes or stamped steel plates. Due to technological progress and the development of high-strength aluminum alloys, most of them have been used Aluminum. The bracket made of aluminum alloy should have high torsional rigidity to ensure the stability and reliability of the operation. During the driving process, the road surface will produce complex repeated loads. The material should have a certain fatigue strength to ensure the lasting safety and reliability of the parts. ; It should have an eye-catching appearance, bright fashion, etc.
The aluminum alloy rocker support beam is more than 20% lighter than the steel structure, while ensuring high strength and light weight. In 1985, a hybrid support beam was developed. The support of this hybrid beam has high fatigue strength. It is made of 7XXX series alloy extruded profiles. The casting part is made of Al-Si-Mg series alloy with excellent casting performance and suitable for welding. Made of Al-Mg alloy. The welding rod is made of A-Zn-Mg alloy, or AI-Mg alloy with low crack sensitivity. All of them are made of high-strength extruded materials. Although the quality is reduced, the manufacturing cost is increased. Mixed type Brackets are most preferable.
(5) Frame body
The frame body is also called the main beam of the vehicle body. Before the 1980s, the main beam of the motorcycle was always welded with carbon steel pipes, just like the rocker support beam. It also faced the challenges of light weight, high rigidity, high strength and elegant appearance. challenge. The pipe alloy of the welded main beam is Al-Zn-M alloy, which has high mechanical properties and excellent weldability. The strength of the weld seam and transition zone is not much different from that of the base metal, and it has good extrudability , can produce hollow profiles and pipes with complex cross-sections, and 5083 aluminum alloy is also an excellent deformed aluminum alloy. The slewing center casting connecting the main beam and the rocker support beam must have high strength and good appearance. In short, the aluminum alloy used to manufacture main beam parts should have the following properties: high mechanical properties, strength, and toughness, not only must have relatively strong corrosion resistance, but also have good anodic oxidation performance, and the tone of the oxide film should be uniform and consistent. Quite strong metal texture, superior castability, good weldability.
At present, aluminum alloys are widely used in various fields, especially in the field of motorcycles. In order to improve driving performance and brand competitiveness, major manufacturers have successively used aluminum alloys to manufacture various parts. For motorcycle aluminum alloy parts manufacturing, Jiahangaero has more than 20 years of experience, choose Jiahangaero as your motorcycle new project manufacturer, to provide you with professional service, stable delivery and excellent quality. Welcome to contact us.