The manufacturing of an excavator boom arm—a core structural component bearing heavy loads and dynamic forces—follows a rigorous, multi-stage process to ensure durability, precision, and safety. Below is a detailed breakdown of the workflow, key operations, and quality controls:
This stage lays the foundation for the boom arm’s performance, focusing on structural integrity and operational efficiency.
- Core Operations:
- Create 3D models of the boom arm (including main plates, reinforcing ribs, and hinge interfaces) using CAD software.
- Conduct FE simulation via CAE tools to analyze stress distribution, fatigue life, and deformation under extreme working conditions (e.g., lifting heavy materials, digging hard soil).
- Optimize the design: Adjust plate thickness, add/reinforce ribs, or modify hinge positions to reduce weight while maintaining load-bearing capacity.
- Key Tools: CAD (SolidWorks, Creo), CAE (ANSYS, Abaqus), FE analysis software.
- Quality Requirement: Ensure the design meets industry standards (e.g., ISO 10265) for fatigue strength and static load resistance; installation interfaces (e.g., hinge holes) must align with the excavator’s arm cylinder and bucket.
The boom arm relies on high-strength, wear-resistant materials to withstand harsh working environments.
- Common Materials: High-strength low-alloy (HSLA) steel (e.g., Q345B/C, S355JR) or wear-resistant steel (e.g., NM450) for critical stress areas. These materials balance tensile strength (≥345 MPa) and toughness, avoiding brittle fracture.
- Material Preparation: Inspect raw steel plates for defects (e.g., cracks, inclusions) via ultrasonic testing; cut plates into standard sizes for subsequent processing.
Raw steel plates are cut into specific shapes (e.g., main boom plates, rib plates) based on 2D unfolded drawings from the 3D model.
- Core Operations: CNC (Computer Numerical Control) cutting to ensure dimensional accuracy.
- Key Tools:
- Gantry-type CNC plasma cutting machine (for thin-to-medium plates, ≤20mm; fast, low thermal deformation).
- CNC flame cutting machine (for thick plates, >20mm; suitable for HSLA steel).
- Quality Requirement: Dimensional deviation ≤ ±1mm; no burrs or slag on cut edges (to avoid welding defects); thermal deformation controlled via pre-heating or post-cut cooling.
Flat steel plates are bent or rolled to create the boom arm’s box-type structure (high rigidity) and curved sections (for load distribution).
- Core Operations:
- Bending: Use hydraulic press brakes to fold plates into angles (e.g., 90° for box-section walls) or U-shaped grooves.
- Rolling: Use plate rolling machines to form curved surfaces (e.g., the boom’s arc-shaped top/bottom plates) for better stress dispersion.
- Edge Preparation: Bevel cut edges of plates (e.g., 30°–45° bevels) to ensure full penetration during welding.
- Key Tools: Hydraulic press brake, 4-roll plate rolling machine, beveling machine.
- Quality Requirement: Angle deviation ≤ ±0.5°; curved surfaces have uniform radius (no wrinkles or cracks); bevel dimensions match welding specifications.
Welding assembles all formed parts into the final boom arm structure—this is the most critical stage for structural strength.
- Core Operations:
- Tack Welding: Temporarily fix parts (e.g., main plates + reinforcing ribs) with small welds to maintain alignment.
- Main Welding: Use high-efficiency, low-defect welding methods for different joints:
- Submerged Arc Welding (SAW): For long, straight joints (e.g., main plate seams); high deposition rate and smooth welds.
- CO₂ Gas Metal Arc Welding (GMAW): For complex joints (e.g., rib-to-main plate connections); flexible and suitable for on-site adjustments.
- Robotic Welding: For high-precision joints (e.g., hinge interfaces); reduces human error and ensures consistent weld quality.
- Post-Welding Heat Treatment: Heat the boom arm to 600–650°C (stress relief annealing) to eliminate residual welding stress (prevents cracking during use).
- Key Tools: SAW machine, CO₂ GMAW welding torch, robotic welding workstation, heat treatment furnace.
- Quality Requirement: No weld defects (porosity, cracks, incomplete fusion); weld height ≥ 70% of the thinner plate’s thickness; residual stress ≤ 150 MPa after heat treatment.
Machining refines critical interfaces (e.g., hinge holes) to ensure smooth assembly with the excavator’s hydraulic cylinders and bucket.
- Core Operations:
- Fixture Clamping: Secure the welded boom arm to a dedicated fixture (to avoid deformation during machining).
- Boring: Use CNC boring mills to machine hinge holes (for pin shafts) to precise dimensions.
- Milling: Mill the end faces of hinge bosses to ensure perpendicularity with hole axes.
- Drilling/Tapping: Drill holes for hydraulic pipeline brackets or bolt connections; tap internal threads where needed.
- Key Tools: Large CNC boring and milling machine, multi-axis machining center, tapping machine.
- Quality Requirement: Hole diameter deviation ±0.05mm; parallelism/coaxiality of hinge holes ≤ 0.5mm (to ensure smooth pin shaft movement); surface roughness of holes Ra ≤ 1.6μm.
This stage enhances corrosion resistance and improves coating adhesion, critical for the boom arm’s service life in wet/dusty environments.
- Core Operations:
- Shot Blasting: Use high-speed steel shots (0.8–1.2mm) to blast the boom arm’s surface, removing rust, scale, and welding slag.
- Phosphating: Immerse the boom arm in a phosphating bath (zinc phosphate solution) to form a 5–10μm phosphate film (improves primer adhesion).
-
Tempo do bar : 2025-09-24 08:39:24
>> lista da notícia
Por favor verifique seu email!
