Auto Parts

Auto parts (automotive components) are specialized mechanical, electrical, and structural elements that constitute passenger cars, commercial vehicles, and electric vehicles (EVs). These components work synergistically to ensure vehicle operation, safety, comfort, and efficiency—ranging from engine core parts to electronic control systems, chassis assemblies, and body structures. Leveraging advanced manufacturing processes (stamping, forging, CNC machining, and injection molding) and high-performance materials, auto parts must meet stringent industry standards for durability, precision, and environmental adaptability, catering to traditional internal combustion engine (ICE) vehicles and emerging EV/hybrid technologies.

I. Core Classification of Auto Parts

Auto parts are categorized by functional systems, reflecting the complexity of modern vehicles:

1. Engine & Powertrain Components

The "heart" of the vehicle, responsible for power generation and transmission:

Engine Core Parts:

Cylinder Block & Head: Cast iron (ICE vehicles) or aluminum alloy (lightweight EVs/hybrids), precision-machined with CNC technology (tolerance ±0.01mm) to ensure sealing and heat dissipation.

Pistons & Connecting Rods: Forged aluminum alloy (pistons) and high-strength steel (connecting rods), heat-treated to HRC 35–45 for wear resistance.

Valve Train: Valve springs (high-carbon steel, spring rate 5–20 N/mm), camshafts (cast iron), and tappets—critical for air-fuel mixture control (aligns with spring parts detailed earlier).

Fuel System: Fuel injectors (precision-machined brass nozzles), fuel pumps (stamped steel housings), and filters (stainless steel mesh).

Transmission Components:

Gearboxes: Manual (cast iron gears) and automatic (planetary gears, hydraulic clutches), with wave springs (stamped sheet metal) for bearing preload (refer to spring parts chapter).

Driveshafts & Axles: High-strength steel (driveshafts) and alloy steel (axles), welded via robotic MIG welding for structural integrity.

EV-Specific Powertrain: Electric motor stators/rotors (copper windings + stamped steel laminations), battery packs (lithium-ion cells with aluminum alloy casings), and power electronics (silicon carbide semiconductors).

2. Chassis & Suspension Components

Ensure vehicle stability, handling, and ride comfort:

Suspension System:

Leaf Springs: Multi-layered spring steel strips (65Mn, 55Si2Mn) for heavy-duty trucks, parabolic leaf springs (automotive) with fatigue life ≥5×10⁵ cycles (detailed in spring parts).

Coil Springs: Compression coil springs (spring steel, stainless steel) for passenger cars, spring rate 10–50 N/mm, load capacity 5–20kN.

Shock Absorbers: Hydraulic (steel cylinders + oil-filled chambers) and air suspension systems (aluminum alloy airbags), damping vibrations from road surfaces.

Control Arms & Ball Joints: Forged steel (control arms) and hardened steel (ball joints), with rubber bushings for noise reduction.

Braking System:

Brake Discs & Pads: Cast iron (discs) and ceramic-reinforced friction materials (pads), heat-resistant up to 600℃.

Brake Calipers: Aluminum alloy (lightweight) with stamped steel pistons, corrosion-resistant via anodizing.

Brake Lines: Copper or stainless steel tubes (pressure resistance ≥10MPa), flared ends for leak-proof connections.

Steering System:

Steering Rack & Pinion: Precision-machined steel (rack) and cast iron (pinion), with torsion springs (steel) for steering feedback.

Power Steering Pumps: Aluminum alloy housings with stamped steel impellers (hydraulic) or electric motors (EVs).

3. Body & Structural Components

Provide structural integrity, safety, and aerodynamics:

Body Frame:

Unibody (Passenger Cars): Stamped high-strength steel panels (yield strength ≥590MPa) welded via spot welding robots, with crash zones for impact absorption.

Ladder Frame (Trucks/SUVs): Forged steel rails and crossmembers, corrosion-resistant via galvanization (salt spray test ≥1000 hours).

Exterior Components:

Doors, Hoods, & Fenders: Stamped steel (economic models) or aluminum alloy (premium/EVs), surface painted via electrostatic spraying (paint thickness 80–120μm).

Bumpers: Plastic (ABS/PC) with steel reinforcement beams, impact-resistant (drop test from 1.5m height).

Windows & Mirrors: Tempered glass (windshields) and aluminum alloy mirror housings (stamped + anodized).

Interior Components:

Seats: Steel frames (stamped + welded) with foam padding and fabric/leather upholstery, seat adjusters with torsion coil springs (detailed in spring parts).

Dashboard & Trim: Injection-molded plastic (ABS/PP) and aluminum alloy accents, flame-retardant (UL94 V-0 rating).

Safety Features: Airbags (nylon fabric + inflators), seatbelts (webbing + steel buckles with tension springs).

4. Electrical & Electronic Components

Control vehicle systems and enhance user experience:

Battery & Charging:

12V Lead-Acid Batteries (ICE) and High-Voltage Li-Ion Batteries (EVs, 200–800V), with aluminum alloy casings and thermal management systems.

Alternators & Starters: Stamped steel housings, copper windings, and carbon brushes (alternators); DC motors (starters) with planetary gear sets.

Electronic Control Units (ECUs):

Engine ECU, ABS ECU, and Infotainment Systems: Printed Circuit Boards (PCBs) with microchips, capacitors, and connectors (beryllium copper contact springs, detailed in spring parts).

Sensors: Temperature sensors (stainless steel probes), pressure sensors (brass housings), and camera modules (plastic + glass lenses) for ADAS (Advanced Driver Assistance Systems).

Lighting & Signals:

Headlights/Taillights: LED bulbs (energy-efficient) with plastic housings (PC/PMMA), waterproof (IP67).

Wiring Harnesses: Copper wires (tinned for corrosion resistance) with plastic insulation, organized via plastic clips and steel brackets.