Analysis of Fastener Quantity and Types in Electric Vehicle Chassis

Analysis of Fastener Quantity and Types in Electric Vehicle Chassis

A typical electric vehicle (EV) chassis requires 300–500 fasteners, depending on the vehicle type (e.g., compact sedan vs. midsize SUV) and design complexity. Below is a detailed breakdown of key components and their fastener types/quantities:

1. Subframe-to-Body Connection

• Quantity: 80–120 fasteners
• Primary Types:
  • High-strength flange bolts (ISO 4162): M10–M14, Grade 10.9, for rigid subframe-body connections (e.g., Tesla Model 3 uses 92 bolts).
  • Self-locking nuts (DIN 985): Paired with flange bolts to prevent vibration loosening.
  • Structural rivets (EN 15048): Aluminum lightweight connections (~15% of total).

2. Suspension System

• Quantity: 120–180 fasteners
• Critical Components:
  • Control arm-to-knuckle joints: M12–M16 bolts (ISO 4017 Grade 10.9), ~30–40 per suspension side.
  • Shock absorber mounts: M10 high-strength bolts + anti-loosening washers (DIN 6798), 4 per shock.
  • Stabilizer bar bushings: M8 stainless steel bolts (A2-70), corrosion-resistant coating.

3. Battery Frame-to-Chassis Mounting

• Quantity: 60–100 fasteners
• Types:
  • Battery pack bolts (ISO 7380): M10–M12 titanium alloy or zinc-plated steel, tensile strength ≥1,000 MPa (e.g., BYD Blade Battery uses 78 bolts).
  • Nylon-insert lock nuts (JIS B 1181): Prevent vibration-induced displacement.

4. Braking System

• Quantity: 40–60 fasteners
• Key Applications:
  • Caliper mounting bolts (ASME B18.2.3.9M): M8–M10, Grade 12.9, 4 per caliper.
  • Brake rotor locating pins (DIN 7): Precision tolerance (±0.02mm) to prevent uneven wear.

5. Drive Motor & Reducer Assembly

• Quantity: 50–80 fasteners
• Core Fasteners:
  • Motor flange bolts (ISO 4014): M12–M14, Grade 10.9, Dacromet coating (heat-resistant ≥300°C).
  • Reducer housing bolts (DIN 6914): M10–M12, preload torque tolerance ±3%.

6. Auxiliary Components (Piping/Wiring)

• Quantity: 30–50 fasteners
• Types:
  • U-bolts (GB/T 880): Secure high-voltage wiring and cooling lines.
  • Plastic clips: Quick assembly for non-structural parts (~20% of total).