Motorcycle Engine Manufacturing Process
We use high-standard materials and advanced processing technology in the processing of key parts of motorcycle engines to ensure high precision, high consistency and high durability, providing solid support for the performance of the whole machine.
Cylinder block processing
Material selection
Mainly high-silicon aluminum alloy (such as ADC12, AC8A), with excellent heat dissipation, corrosion resistance and lightweight characteristics, suitable for both air-cooled and water-cooled structures.
Processing process
Rough processing: Use a vertical or horizontal machining center for contour roughing, reserve fine processing allowance, and ensure the basis of geometric tolerance;
Cylinder bore honing: The inner hole uses an imported honing machine for three-stage honing, controlling the roundness and cylindricity within **±0.005mm, and the surface roughness reaches Ra0.3μm**, which improves lubrication performance and wear resistance;
Cooling channel processing: Five-axis linkage processing completes the internal complex water or oil channels at one time, improving heat transfer efficiency and structural integrity;
Mounting surface processing: Control the flatness and verticality through precision scraping and plane milling to ensure assembly sealing;
Surface treatment: Ceramic spraying, electrophoretic coating, and anodizing can be performed according to customer requirements to enhance corrosion resistance and wear resistance.
Crankshaft manufacturing
Forming method: The crankshaft is die-forged, and the materials are mostly 42CrMo and SCM440 alloy steel, which ensures high strength and fatigue resistance.
Heat treatment process
Overall quenching and tempering: Improve comprehensive mechanical properties;
Induction quenching: The crankpin and the main journal are locally heated and then quickly cooled, and the surface hardness reaches HRC58-62, forming a high-strength wear-resistant layer, and the core maintains sufficient toughness;
Tempering treatment: Eliminate quenching stress and improve organizational stability.
Finishing and dynamic balancing
Use CNC grinders to process crankpins and main journals to ensure dimensional accuracy and surface roughness;
Introduce a dynamic balancing detection system to perform real-time detection and correction on each crankshaft, control the deviation within 1.5g·cm, and ensure operational stability at high speeds.
Camshaft processing
Processing method: Using a CNC turning and milling composite machining center, the cam profile and journal can be processed in one go, reducing cumulative errors.
Key processes
Cam profile grinding: Ensure the accuracy of lift curve and valve timing, and control the profile error within ±0.01mm;
Neck processing: Use center positioning fixture to ensure coaxiality and runout accuracy;
Surface hardening treatment: According to design requirements, carburizing or nitriding treatment is carried out, the surface hardness reaches HRC55-60, and the wear resistance and contact fatigue strength are improved;
Magnetic particle inspection: Detect whether there are cracks and defects after heat treatment to ensure zero defects before leaving the factory.
Cylinder head processing and valve seat installation
Processing equipment: Use high-rigidity five-axis machining center to complete multi-angle processing in one clamping, and improve positioning accuracy and efficiency.
Main processes
Valve seat ring pressing and finishing: Use hydraulic press to control the pressing force to avoid deformation. The valve seat and guide tube are subsequently turned and ground with special tools to ensure sealing;
Spark plug thread processing: Use extrusion tap processing to form, with high thread strength and complete shape;
Cooling system processing: The cooling cavity inside the cylinder head is processed and formed by drilling and milling to avoid the risk of water leakage;
Positioning surface milling: The flatness of the surface connecting with the cylinder body is controlled within 0.01mm to prevent air and water leakage.
Connecting rod manufacturing
Material and forming: Medium carbon alloy steel (such as 40Cr) or powder metallurgy steel is mostly used, and die forging is used to form to ensure a dense internal structure and uniform mechanical properties.
Fracture Split Technology
The connecting rod big end cover adopts a fracture split structure (Fracture Split), which is forged into a whole in one step and then fractured and separated by special equipment;
The fracture surface forms a natural rough surface, which is precisely matched with the body and has a strong self-positioning ability;
Compared with the traditional screw connection method, it improves assembly accuracy and rigidity and reduces abnormal noise.