Digital design Sheet Metal Fabrication error is more hidden problems, analysis of the process of modeling, the possible error elimination measures, analysis of the NC measurement error accumulation problem. In addition, Hangzhou Sheet Metal Fabrication analysis of the measured point cloud surface and the optimal fitting results, given the new standard of error evaluation. Through the above measures, you can reduce the processing error, improve the qualified rate of parts.
1, equidistant surface error and elimination method:
We used CATIA software to analyze the thickness of the 1.016 mm sheet metal machined part when it was found in some places with a thickness of 1.021 mm, 0.005 mm difference, and the results show that when using equidistant surface functions as equidistant surface errors. In order to reduce the error, the accuracy required for the project is to ensure that the maximum deviation of the offset surface is within the allowable error range of the item, and then, when it is necessary to offset many times, if possible, use each transition, the original surface rather than the previous Offset surface.
2, the measurement error caused by improper selection:
Sheet metal mold CNC machining processing, dial out the above indicators are often not the design basis, the benchmark CNC machining process processing characteristics, relative to the tire design benchmark error on the tire mold processing error. After the completion of the entire tire mold processing, the measurement error of the dead edge tires, the appearance and the like is twice as large as the design tolerances of the reference due to the accumulation of tolerances. Assumed shape tolerance ± 0.25 mm Tire design tolerance + 0.8 mm, for these reasons the shape relative to the measurement reference size is + / - 0.16 mm, it is easy to cause the illusion of measurement results.
The measurement basis for reducing the error should be consistent with the design basis. In addition, the measured point cloud surface fit and the best fit part records almost at least one transformation, and can also improve the yield of Sheet Metal Fabrication parts.