Surface Inspection of Metal Parts

The functional surfaces of automotive parts must meet the highest demands. Sealing surfaces of flanges are one example of such functional surfaces. Flanges are used as connecting elements of tubes. The sealing surfaces must be flat and without defects to ensure their sealing properties.

The use of automated machine-vision systems contributes significantly to constantly good product quality and a crucial reduction of inspection costs.

Details of the inspection:

  • Inspection objects: flanges in motion (conveyor belt), dimensions max. 180 x 140 mm
  • Automated 100% control with two inspection tasks:

1. Detection of surface defects

2. Height measurement of the inspection objects

  • Short acquisition time (high cycle rates possible): cycle rate max. 5000 parts/h, approx. 700 ms per part.
  • Thickness inspection in 3D image: critical tolerance +/-0.15 mm


1.   Surface Inspection with trevista®

The surfaces of the flanges are checked for scratches, indentations, bulges, and shrinkage cavities with a trevista® X.4 system. The result images are evaluated with the software Coake® 7.


Fig. 1: trevista® enables reliable defect detection even on glossy surfaces.

2. Height Measurement of the Inspection Objects

Beside surface defect detection, also the planarity, height, and thickness of the sealing surfaces are measured.

For this task, two ECCO 75.100 sensors from Smartray are used in multi-sensor registration mode (MSR).

The MSR approach makes it possible to check larger objects for finest characteristics without loss of accuracy. The two sensors act like a single 3D sensor and provide the measured values as a calibrated image. The resolution of the individual sensors is preserved. The fields of view of the sensors are connected via software (Coake® 7). This happens in just a single work step, which prevents additional constructive work at the machine and saves valuable process time.  


Fig. 2: Multiple sensors measuring in one coordinate system (connected via MSR).

ECCO meets Coake® 7

The Coake® 7 software is used to evaluate the measured values from the planarity, height, and thickness measurements. Coake® 7 joins the two images of the ECCO sensors into a conclusive result image.


Fig. 3: Coake® 7 joins the two images of the ECCO sensors into a conclusive result image.

Based on the results of both inspection tasks, the flanges are evaluated as good or bad parts and automatically sorted. The high precision of the inspection system ensures an extremely low pseudo-reject rate.


Fig. 4: Perfect match: Coake® 7 and ECCO sensor

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