I. Application Background & Industry Pain Points of Crankshaft Cleaning

1. Workpieces to Be Cleaned & Types of Contaminants

Workpieces: Ductile iron crankshafts, forged steel crankshafts for passenger and commercial vehicles, as well as crankshafts for range extenders of new energy vehicles. Structural features include main journals, crankpin journals, crank webs, counterweights, through main oil galleries, inclined intersecting connecting rod oil holes, threaded oil plug holes, fillet transition zones and oil seal mounting positions.

Contaminants: Turning/grinding emulsion cutting fluid, iron chips, grinding sludge, polishing paste, heat treatment scale, anti-rust oil and micro burrs.

Mandatory industry standard: Comply with ISO 16232 Cleanliness Standard for Automotive Components. Hard particulate matter inside oil galleries shall not exceed 150μm; surface oil and chip residues must meet standards to eliminate bearing shell wear and engine seizure failures caused by blocked oil holes.

2. Deficiencies of Conventional Cleaning Equipment

1. Simple spray cleaning: Deep intersecting oil holes and blind holes of crankshafts cannot be thoroughly flushed. Fine iron debris get trapped at the corners of oil galleries, resulting in unstable cleanliness and high rework rate for mass production.

2. Standalone ultrasonic cleaning: Unable to fully cover large long crankshafts. Residues hidden in gaps of counterweights and crank fillets cannot be completely removed; water stains easily remain after drying and cause rust spots.

3. Non-CNC calibrated high-pressure equipment: Nozzles need manual position adjustment, consuming long time for model switching of different crankshafts. Unzoned adjustable high pressure may scratch finely machined journal surfaces by impact.

4. Single-station standalone operation leads to long cycle time, incompatible with automated machining production lines. Lack of production data recording fails to meet traceability requirements of OEMs under IATF16949.

II. Custom Core Configuration of Bakr CNC High-Pressure Washing Machine for Crankshafts

Model: Sinobakr Six-Station Servo CNC Intelligent High-Pressure Cleaning Center, specially customized and developed for heavy long shaft workpieces such as crankshafts.

1. Core Hardware Parameters

1. Graded high-pressure water supply system: Stepless pressure regulation from 0 to 60MPa. The standard crankshaft process adopts 22–30MPa for targeted deburring inside oil holes, while low-pressure spraying is applied to protect journal surfaces. The high-flow high-pressure water channel delivers penetrating cleaning for through long oil galleries without blind spots.

2. Multi-axis CNC servo linkage system: X/Y/Z three linear axes plus A-axis 360° indexing rotation for workpieces, positioning accuracy ±0.08mm. Equipped with a magazine of retractable extended rotating high-pressure nozzles for automatic tool change, precisely aligning with each group of inclined connecting rod oil holes and branch holes of main oil galleries.

3. Crankshaft-specific clamping fixture: Center positioning via tips at both ends, with auxiliary crank supports to suppress vibration during high-speed rotation of long crankshafts. Simply replace quick-positioning fixture plates to adapt to full-series crankshafts ranging from 800mm to 2200mm, with one-click program call for model switching.

4. Integrated six-station production line: High-pressure rough cleaning → medium-pressure fine flushing → deionized water precision rinsing → multi-stage air knife dehydration → vacuum hot air drying → anti-rust sealing. Synchronous parallel processing at each station, with single-piece cycle time of 45–120 seconds.

5. Multi-stage water circulation purification system: Four-stage precision bag filter, high-strength magnetic iron remover and automatic oil-water separation slag discharge device, filtration precision 3–15μm. Closed-loop recycling of cleaning liquid greatly reduces consumption of pure water and chemicals.

6. Intelligent industrial control system: 19-inch industrial touch screen with Codesys motion control platform, preloaded with dozens of exclusive crankshaft cleaning process programs. Real-time monitoring of pressure, water temperature, cleaning duration and filter element differential pressure, early warning of service life for wearing parts, exportable production data for docking with factory MES.

2. Exclusive Optimized Structural Design for Crankshafts

• Multi-point follow-up auxiliary support structure eliminates rotational runout of long crankshafts, ensuring no unclean blind zones on crank webs and counterweights.

• Retractable extended rotating high-pressure nozzles can stretch into through main oil galleries of crankshafts to clear accumulated chips and heat treatment scale at oil gallery corners.

• Independent zoned water channel control: Separate pressure control for high-pressure flushing zone of oil holes and low-pressure protection zone of finely machined journal surfaces to avoid scratches and impacts on precision journals.

• Composite vacuum hot air drying system extracts deep water vapor inside oil galleries to prevent oxidation rust and residual watermarks on cast iron crankshafts after machining.

• The entire cleaning chamber of the machine adopts 304 stainless steel, resistant to corrosion by water-based cleaning agents and free of secondary impurity shedding that contaminates workpieces.