Komatsu PC300 Excavator Connecting Rod Assembly I-shaped Frame

I1.Precise Drawing Analysis and Process Planning

Before production, our professional team uses Komatsu's original technical drawings as the basis to conduct in-depth analysis of dimensional tolerances, assembly accuracy, and mechanical performance requirements. We then develop a tailored production process plan, ensuring every step complies with the original factory's technical standards. This guarantees perfect compatibility between the I-frame and the Komatsu PC300 excavator.

2.High-Precision Blanking: Laser Cutting Technology

We use laser cutting equipment to blank the Q345B steel plates. Laser cutting achieves an accuracy of ±0.1 mm, enabling precise cutting of complex contours. This avoids dimensional deviations and material waste common in traditional cutting methods, while also ensuring smooth, flat cut edges-laying a solid foundation for subsequent processing.

3.Forming: CNC Equipment Ensures Accuracy

CNC Bending: After cutting, the steel plates are precisely bent using a CNC bending machine. Bending angle and pressure are controlled via computer programming, resulting in a regular structure that meets all drawing specifications once formed.

CNC Boring: For the I-frame's assembly holes, we use a CNC boring machine to ensure the center-to-center distance deviation of the holes is ≤0.05 mm. This guarantees smooth assembly with subsequent components (e.g., pins, connecting rods) and prevents operational jamming caused by hole position deviations.

4.Assembly Welding: Custom Tooling + Robotic Welding for Strength and Consistency

Custom Tooling Assembly: We use custom-made assembly tooling designed specifically for the Komatsu PC300 I-frame. Through the tooling's locating pins and clamping mechanisms, each component is precisely fixed in its preset position, with an assembly deviation of ≤0.2 mm. This completely eliminates position deviations caused by manual assembly.

Robotic Welding: Welding robots handle the welding process, offering high stability and uniform weld formation. Weld penetration meets standards, effectively avoiding defects like missed welds or cold welds that can occur with manual welding. Additionally, we use inert gas shielded welding to reduce weld oxidation, enhance weld fatigue strength, and ensure the I-frame's welding strength and service life.

5.Surface Treatment: Protective Coating for Enhanced Corrosion Resistance

After welding, we remove oil stains and oxide layers from the workpiece surface through pretreatment processes (degreasing, derusting, phosphating). We then apply a high-temperature baking and painting process, spraying rust-resistant primer and wear-resistant topcoat to achieve a film thickness of 80–100 μm. This effectively isolates moisture, dust, and corrosive media, boosting the I-frame's rust resistance and making it suitable for harsh outdoor working environments.