3D Quality Inspection of Crankcases for Four-Stroke Engines
Highly complex engine crankcases containing components rotating up to 10.000 revolutions per minute (rpm): This is where precision down to the millimetre is required!
Print3D Quality Inspection of Crankcases for Four-Stroke Engines
Weber Motor GmbH in Markdorf (Germany) is member of the Weber Group and for more than 40 years has been a competent and reliable partner for their global customers for the development and production of engine components, engine systems, complete engines as well as fibre reinforced composite components.
Quality is considered a key factor for the competitiveness and success of the company, which is why the entire production process has to comply with very high quality standards. In connection with the production of aluminium cast parts used for the manufacturing of Weber’s powerful four-strokes engine, the exact adherence to these quality requirements can be verified by CAD comparison with the help of a flexible Breuckmann 3D digitisation and measuring system, the smartSCAN 3D-HE.
Objective and Measuring Object
The crankcase to be measured in this particular project has been manufactured using the sand casting method and fulfils a number of various functions: It is here where the crankshaft and the balance shaft are plain bearings and are being subjected to the ignition forces of the combustion engine (axial and radial). Furthermore, the crankcase accommodates the oil pressure pump with the pressure relief valve and it is here where the compressed oil is channelled to the relevant
bearing points.
Finally, it also serves as a cover for the timing driveshaft and gears. The cast aluminium crankcase therefore constitutes an important category ‘A’ component; depending on the application, the internal engine components contained in a crankcase can reach rpm ranges of up to 10.000 rpm.
Because of the increased likelihood of possible shape deviations as a result of the chosen casting method, it is vital that the crankcases are measured and examined with regard to any potential deviations from the specified requirements. Given the complex geometry of the unfinished parts, the surface acquisition carried out by means of a coordinate measuring machine has proven to be rather time-consuming and labour-intensive: In addition to comprehensive programming tasks, also significantly more time for the generation of the drawing as well as the documentation has to be accounted for. A variance comparison based on the precise three-dimensional data sets generated by the area measuring system smartSCAN 3D-HE therefore provides the perfect time and resource saving alternative.
Measuring System and Setup
The inspection of the unfinished components is carried out with Breuckmann‘s measuring system
smartSCAN 3D-HE, in this case configured with a small field of view.
In order to achieve a partially automated data capturing process, the measuring setup also employs a turntable.
- Deviation of the crankcase to be inspected from its target values (3D false colour image)
Workflow
With the aid of the Breuckmann software OPTOCAT, the scanning process firstly produces individual data recordings of the crank-case, thereafter aligns them and joins them to a homogeneous triangulated mesh. In a second step, the generated data sets are evaluated with the aid of a special inspection software (in this case Polyworks/InspectorTM by Innovmetric Software Inc.), in order to assess the geometry.
Area measuring optical sensors using only standard triangulation angles are often not able to capture deep serration textures at the required level of precision. The flexible sensor configuration of the smartSCAN 3D product series enables scanning procedures at triangulation angles of 30°, 20° and 10°, thus allowing even very difficult accessible object areas to be measured at a high degree of detail and accuracy.
Conclusion
The high-precision data of the smartSCAN 3D-HE provides Weber Motor GmbH with the necessary support to ensure compliance with their demanding quality standards. In order to perform conclusive inspections of the crankcase production, the caster has access to a 3D data set which within a certain shape deviation tolerance complies with the respective DIN 1680 GTA guidelines: After the casting process is completed, the crankcase is digitised with the smartSCAN 3D-HE system and compared against the CAD reference data.
The time-consuming procedure with the tactile measuring sensor of a coordinate measuring machine is no longer necessary; not only can every smallest shape deviation be identified faster, easier and at higher accuracy, also the overall digitisation process together with the subsequent data comparison gives valuable time and cost savings.
The measuring results are instantaneously interpretable and immediately
channelled into the optimisation of the process parameters. In doing so, the smartSCAN 3D-HE serves to support and to ensure the consistent efficiency
required by the Weber Motor production department in order to manufacture top quality crankcases.
We would like to take this opportunity to thank Weber Motor GmbH for their kind support in compiling this application report.
