The automobile is a complicated mechanical system. Through the lightweight structure optimization design of the core components and the application of lightweight materials such as high-strength steel, aluminum / magnesium alloy, carbon fiber composite materials and advanced manufacturing and forming processes, it is estimated that by 2030, Carbon fiber hybrid body as the representative of the lightweight components will account for 40% of the market.
Engine and transmission system core components technology route
Engine and transmission system components of the core technology line shown in Figure 1.
1. Passenger car engine cylinder head and exhaust manifold modular design
Engine modular design is an important means to achieve lightweight engine.In the supercharged gasoline engine, the engine cylinder head and exhaust manifold modular design, on the one hand the exhaust manifold can be cooled to improve economy, to solve Exhaust temperature over the reliability of the problem; the other hand, can reduce the exhaust pipe flange, bolts and other coupling parts size, can greatly reduce the quality of the whole machine. For about 2L of gasoline booster engine can reduce the mass 2 ~ 3kg, one of the important ways to reduce weight.
2. Passenger car engine cylinder block
Cast iron cylinder body to ensure that the wall thickness, reduce the thickness tolerance, the optimization of local structure, combined with the improvement of the casting process to reduce weight.Optimize the main bearing wall, cylinder skirt, upper and lower flange surface structure, weight reduction 2% ~ 3%; Optimize the structure of the main bearing cap by topological analysis, and reduce the weight by 1% ~ 3%; The cast aluminum cylinder body gives priority to the technical scheme of using the aluminum die-casting cylinder body. Lightweight. The main content is to solve the structural design of cast aluminum cylinder, die casting process design process problems, and then expand the application.
Crankshaft
The engine crankshaft mainly adopts the casting crankshaft of hollow structure of the main journal and connecting rod journal to achieve the purpose of weight reduction. The structure can be optimized in terms of the number and size of the balancer, the shape of the crank, the shape of the crankshaft, etc. In the material, Strength ductile iron roll crankshaft, replacing the existing forged steel crankshaft.
Camshaft
Assembled hollow camshaft is a very mature camshaft lightweight technology, can achieve more than 30% weight reduction, has been widely used in foreign engines.
5. Drive shaft
The longer the shaft length, the traditional steel shaft tube due to lower modalities, NVH can not meet the requirements and can only be made into two sections. Carbon fiber shaft tube mode is high, just made into a period, so you can save A universal joint, bearings and intermediate support, the structure is greatly simplified, the weight is also significantly reduced.Carbon fiber transmission shaft as a whole than the traditional steel shaft weight loss of about 50%.
Body core components lightweight technology roadmap
For the load-bearing body, lightweight aluminum technology is one of the directions of the direction of the road, the second is the direction of the steel-aluminum hybrid body, the direction of the three is based on carbon fiber-based multi-material hybrid body.The problem to be solved is the aluminum alloy material Performance testing and evaluation of aluminum / composites, simulation of aluminum / carbon fiber body performance (strength and safety, etc.), tooling manufacturing techniques and joining techniques for different materials.
For non-load-bearing body, one of the lightweight technology directions for the carbon fiber body and plastic body cover, the second is the use of aluminum frame body weight body and body parts of the lightweight technology route shown in Figure 2 Show.
In the application of lightweight materials, the main use of high-strength steel, aluminum / magnesium alloy and carbon fiber composite materials. High-strength steel is mainly used for body panels and body structure parts, deformation of the body parts and structural components in the application of development than Fast, such as the increasingly widely used aluminum alloy trunk lid, hood, back door, bumper beam, etc. Magnesium alloy currently used in the body mainly in the steering wheel skeleton, dashboard skeleton, seat skeleton, etc. Cost and performance of the composite material can be used for structural body parts based on resin-based carbon fiber reinforced composites as the preferred carbon fiber composite materials in the car can be mainly used in the hood, fenders, roofs, luggage, door panels, Chassis and other structural parts.
In the advanced technology, the main use of thermoforming technology, laser tailor-welded plate technology, ranging from the thickness of the rolling plate / difference plate technology, roll forming technology. Thermoforming with high precision forming, forming a good performance, has been widely For the production of high-strength car bumpers, door bumper, A pillar, B pillar, C pillar and the roof frame, the passage and other safety parts and structural parts, etc. Tailor welded plate technology can be applied to the body side frame, Door panels, windshield / front windshield, wheel cover, floor, middle pillar (B pillar), etc., the difference plate can replace the laser tailor welded plate, more suitable for the manufacture of beam components, such as the channel stiffener , The front floor stringers, the rear bumper beam, the rear floor beams, etc. Rolling forming technology can be reasonable geometry section profiles designed to improve the carrying capacity and reduce parts weight.
Chassis system core components technology road map
The chassis of the car is divided into four parts: suspension system, driving system, steering system and braking system. The core components of the technical route shown in Figure 3.
1. Suspension system
The control arm of the suspension system mainly adopts the control arm of cast aluminum, wrought aluminum or carbon fiber composite material to realize the weight reduction; the horizontal stabilizer bar mainly adopts the hollow or carbon fiber composite transverse stabilizer bar to achieve the light weight target; the helical spring mainly adopts the high-strength steel hollow coil spring Or carbon fiber composite coil spring lightweight.
2. Travel system
Driving system wheels are mainly made of aluminum alloy casting, aluminum forging, magnesium alloy forging or carbon fiber composite wheels to achieve weight reduction.
3. Turn to the system
The steering system mainly adopts the electric power steering system and the steer-by-wire steering system to realize the weight reduction.For the steering knuckle with cast iron material, the weight can be reduced through the structural design topology optimization or the weight reduction can be achieved by using cast aluminum, wrought aluminum and carbon fiber composite knuckles .
Braking system
Brake system integration is the future direction of the brake system light weight.Can be used traditional vacuum booster, ESP, vacuum pump (under the conditions of vacuum) combined brake system or traditional vacuum booster, ESP, vacuum pump combination Type, a small number of models using hydraulic vacuum booster pump system, or further use of ESP and hydraulic booster brake system integrated brake disc brake disc combination of the main use of lightweight, such as the steel cap or aluminum cap + Ceramic friction ring brake disc. Brake calipers mainly aluminum caliper to achieve weight.
