Ford Global Powertrain needed to confirm the hypothesis that the cracks in the cylinder bores were caused by high cutting forces attributed to dull tools. Third Wave Systems’ AdvantEdge was selected to analyze the machining process. AdvantEdge analysis helped predict the forces at various stages of the tool wear of the inserts. The study helped ascertain the maximum allowable wear for the inserts and an effective tool change strategy to prevent the cracking from occurring in the future.
Ford Global Powertrain
Solving the mystery of cracks in the cylinder bores using AdvantEdge
CHALLENGE
Ford had to occasionally scrap engine blocks due to cracks observed in the cylinder bores. The hypothesis that the cracking was caused by high cutting forces due to dull tools needed to be confirmed and a solution identified. This exercise required a detailed study of the wear patterns to understand the change in cutting forces. Understanding the impact of evolving cutting edge profile on the the cutting forces required AdvantEdge analysis.
APPROACH
As a first step, the tool insert geometries were created using the tool drawing. Additional tool models were created by characterizing the wear pattern at specific instances during the course of a production run. These geometries were analyzed in AdvantEdge to understand the cutting forces and the resultant stress on the workpiece. Once the baseline was established, the engineers used AdvantEdge to determine the maximum allowable tool wear to ensure that the stress on the workpiece did not exceed the compressive stress of the machined material.
IMPACT
- Confirmed the hypothesis about the source of cracks in the cylinder bores without having to disrupt production
- The detailed characterization of the cutting edge helped determine the acceptable tool wear and identify a standardized metric for tool change in production environment
