Detecting tool crack propagation

Issue

Die cracking occurs in the forging process of automotive parts

• The die is not noticed until it cracks, and the cracks in the die forming area are transferred to the product, resulting in defective products.
• Visual inspections are conducted to prevent defective products from leaking out, but there is variation among operators.
• Periodic replacement of dies at short life settings is costly.

Solution

A ring-shaped jig is placed on the outer diameter of the die, and the ring is tightened with the piezoelectric load sensor "PiezoBolt".
We measured the cycle from the time the die was installed until it was damaged.

As a result, it was found that it is possible to detect minute vibrations when die cracks occur and pattern the degree of progress until they are transferred to the product by the number of abnormal waveforms that occur. By counting the number of abnormal waveforms that occur during production and establishing a system that sends out an alarm and stops the equipment when the number exceeds a set number, it is possible to prevent the outflow of defective products.

Result

Improved production efficiency through advance detection of die cracks

• The company was able to notice minute damage occurring inside the die, preventing mass production of defective products.
• Predicting the approaching life of the dies and regrinding the dies allows them to be used longer.
• Since production is now controlled by quantifying data rather than relying on individual workers, standardization of the production site has been achieved.