Table of Contents
I. Design
The concept design process is divided into three main stages: general layout, styling design, and clay modeling.
(1) General Layout (Sketch)
This stage defines the overall vehicle design, including the layout of the cab, engine, clutch, transmission, drive shaft, frame, suspension, braking system, fuel tank, spare tire, trunk, and air-conditioning unit.
(2) Styling Design (Hand Sketches)
Once the basic dimensions are determined, both exterior and interior designs are developed through sketches.
(3) Clay Model Development
Using design software such as Alias, engineers create 3D digital models that can be directly milled by a five-axis machine to produce clay models (typically at a 1:5 scale). After completing styling, the project enters the engineering design phase, where each subsystem is developed in detail by specialized departments.
II. General Layout Design
In this phase, each component’s position and dimension are refined. Detailed layouts are created for the engine bay, chassis, interior, exterior, and electrical systems.
(1) Body Styling Data
After the clay model is completed, 3D scanning generates point cloud data, which is used in CATIA, UG, or Imageware software to construct the vehicle surface model.
(2) Engine Engineering Design
Mature powertrains are typically used, with layout and matching optimized according to new vehicle requirements, in parallel with chassis development.
(3) Body-in-White (BIW) Design
The BIW consists of welded structural and outer panels (e.g., hood, fenders, side panels, doors, trunk lid). It ensures the structural rigidity of the vehicle. 3D modeling and analysis are carried out using software such as UG and CATIA.
(4) Chassis Engineering Design
The chassis includes transmission, steering, suspension, and braking systems. Calculations, modeling, virtual tests, and prototype part development are performed to complete detailed 3D assembly drawings.
(5) Interior and Exterior Design
Interior design includes dashboard, steering wheel, seats, seat belts, airbags, carpets, trim panels, visors, armrests, and mirrors. Exterior design covers bumpers, glass, trim moldings, grilles, roof racks, sunroofs, mirrors, and sealing strips. These parts are often supplied by OEM partners, but material and structural validation remain essential.
(6) Electrical System Design
Covers the design of wipers, HVAC systems, meters, switches, exterior and interior lighting. After all subsystems are completed, a full vehicle technical specification and bill of materials are prepared.
III. Testing
Prototype testing includes performance and reliability evaluation.
(1) Wind Tunnel Test – Conducted from the clay model phase for aerodynamic analysis.
(2) Proving Ground Test – Simulates various road conditions (gravel, wet, rough, slope) to assess overall performance.
(3) Road Test – Conducted nationwide under different climates (from Heilongjiang to Hainan) to verify driving performance and reliability on highways, dusty roads, concrete, and icy surfaces.
(4) Crash Test – Evaluates structural strength and occupant safety using dummy sensors for impact data analysis and design improvement.
IV. Manufacturing
Automobile manufacturing involves four key processes: stamping, welding, painting, and final assembly.
(1) Stamping
Steel sheets are cut and pressed into specific shapes using dies. Die precision determines part quality.
(2) Welding
Stamped parts are joined by heating and pressing. Spot welding is most common and directly affects body strength.
Large body components are often handled using a 5 ton gantry crane to ensure smooth lifting, precise positioning, and safe welding operations.
(3) Painting
The painting process protects against corrosion and enhances appearance. It includes pre-treatment, priming, coating, and baking — requiring precise control of chemical and mechanical parameters.
(4) Final Assembly
This stage integrates all major components — body, engine, transmission, dashboard, lamps, and seats — into a complete vehicle.
In modular assembly lines, a portable gantry crane is often used to lift and position small to medium modules (e.g., dashboards, chassis subassemblies). Compact, mobile, and easy to operate, this crane improves flexibility and efficiency in limited spaces.
The modular assembly concept, popularized in the late 1990s, shortened production lines and reduced costs. Modern assembly shops typically consist of four modules: front-end, dashboard, lighting, and chassis. After assembly and quality checks (wheel alignment, lighting inspection), the vehicle is ready for delivery.