CASE STUDY: HPL Technology for Cam Grinding

500,000 more camshafts per year!

This case study describes the successful implementation of HPL bonding technology for high-production cam-form grinding of fuel injection pump shafts.

Background

• High-volume producer of fuel injection pumps
• 14 Studer grinding machines producing 7 million pump shafts per year
• Originally using Meister HPB (High Performance Bond) vitrified CBN wheels and hDD Hybrid Rotary Dressing Tools.
• Goals were to increase production capacity and reduce abrasive cost/part.

Original Process Parameters

• Part: pump shaft cam
• Material: steel 100Cr6
• Hardness: 60-64 HRc
• Stock removal: Ø0.5mm
• Finish: 3-4 µm Rz
• Machine: Studer S22
• Wheel speed: 60 m/s
• Coolant: oil
• Dressing ratio: +90%
• Dress interval: 150 parts
• Grind time: 15 sec

Tools Comparison

Process Improvements

• Grind time: from 15-sec to 13-sec (13% improvement)
• Dressing Interval: from 150 to 250 parts (67% improvement)
• Surface finish: from (3-4) Rz to (3-3.5) Rz (improved part quality)

Results

• Capacity increase due to time savings of 2sec per part resulted in 162 days per year (= additional production of 500,000 shafts)
• Grinding wheel tool life increased from 70,000 to 115,000 parts (tool consumption reduced from 100 to 61 wheels per year)
• Savings in downtime (wheel change 20min x 39 wheels = 13 hours or additional production of 1,700 shafts)
• Overall improved size and form holding
• Stresstec-Reading was more constant

For more information about this case study and how HPL technology could help you improve your own grinding process, see  our article; “Custom Tailored Solution” – 500,000 more parts a year”.