Previous Edition Specification 2017-04 Class: Dimensions, tolerances Class No.:01 Documentation of components by means of 3D data models 516 Part name (for databases) 2009-09 3D data models 852 005 160 4 JED 1 Scope This standard is the guideline for tolerancing and documentation of parts that are sampled and released on the basis of a 3D data model. In this process, the geometry (actual contour) is scanned, e.g. using laser scanning, and the result is analysed using a dedicated software including comparison to the CAD data (desired contour). The aim is to directly use the 3D-CAD model for sampling. This will considerably reduce the amount of work required for documentation, sampling and in-process monitoring. 2 Applicable standards ISO 5459 ISO 8062 ISO 1660 DIN 16742 JED-392 Geometrical tolerancing Dimensional and geometrical tolerances for moulded parts Dimensioning and tolerancing of profiles Plastics moulded parts Tolerances and acceptance conditions Technical conditions of delivery for castings made of metallic materials 3 Process chain The data record used for documentation consists of the 3D-CAD model, preferably created in CREO, and a simplified drawing. Along the process chain, the 3D-CAD model is the leading geometry description (digital master). It must be ensured that, along the process chain, the dimensions of the digital master remain unchanged. This includes the possibility of conversion. The simplified technical drawing complements the CAD model and provides important information, e.g. functional dimensions, dimensional tolerances, geometrical tolerances, material designations. Process chain: 1. Creation of the Component Documentation a) Creation of the CAD model b) Determination of the general tolerance c) Determination of the datum-systems d) Determination of the specific tolerances (dimensional and geometrical) e) Creation of the drawing 2. Manufacturing and delivery of the parts 3. 3D-scanning 4. Analysis and assessment of the 3D data 5. Change management JED.dot Template version 03 Continuation page 2 to 6 Compiler Approved Product Group: 4961 Doc. Code Language Rev. O. Hilla S. Eisfelder 008 - en - B
JED-516 : 2017-04 Page 2 4 Creation of the CAD model The CAD model shall be exact (nominal dimensions) and complete, i.e. all the features, such as draft angles, roundings, holes and ribs, shall be included. All the tolerances shall be symmetrical. Threads and gear teeth shall not be detailed in the model. Instead, they shall be represented in the simplified drawing. 5 Determination of the general tolerance A general tolerance has to be specified for the 3D CAD model. The general tolerance is defined as profile tolerance complying with ISO 1660 Dimensioning and tolerancing of profiles : Figure 1: Symbol acc. to ISO 1660 The tolerance zone is limited by two surfaces enveloping spheres of diameter t (in which t is the tolerance value), the centres of which are situated on a surface having the theoretically exact geometrical form. Figure 2: Definition of profile tolerance Unless otherwise limited, the general tolerance will apply to the entire component. Guideline values are given in tables 1, 2 and 3. For other materials/processes see related complementary standards. space diagonal Tolerance 0.6 0.7 0.8 1 1.2 1.4 value t Table 1: General Tolerance [mm] Pressure die casting space diagonal Tolerance value t 50 > 50 to 100 Table 2: General Tolerance [mm] Cast iron space diagonal Tolerance value t 50 > 50 to 100 > 100 to 200 > 100 to 200 > 200 to 400 > 400 to 600 > 600 1.6 2 2.4 3 3.6 4.4 Table 3: General Tolerance [mm] Plastic moulded parts > 200 to 400 > 400 to 600 > 600 30 > 30 to 100 > 100 to 250 > 250 to 400 > 400 to 1 000 0.5 1 2 4 6 The determination of the general tolerance shall be agreed between the responsible engineer, the supplier and the quality engineer.
JED-516 : 2017-04 Page 3 6 Determination of alignment of the geometry. The alignment of geometry means determination of the alignment between 3D-CAD exact geometry and 3D-scanned shape. The alignment shall be defined to provide the basis for orientation of the actual contour as related to the CAD data. The determination of the alignment is crucial for the geometry assessment and may be differently defined, depending of the purpose of geometry analysis. Inspection softwares are capable to define: 6.1 Best fit alignment The software automatically finds best average alignment between overall geometry 3D-CAD exact geometry and 3D-scanned object. This type of alignment is used for general investigation between 3D-CAD exact geometry and he scanned object. Figure 3: Example for best-fit alignment 6.2 Alignment by datum systems The alignment is controlled by the user and based on the datum system. 3D-CAD model datums represent exact datums, while for scanned object datums are derived from interpretation of the workpiece. Datum system alignment in this understanding means clear orientation along each of the three mutually perpendicular axes or datum planes. For the definition of the orientation, datums shall be indicated as defined in ISO 5459. Meaningful datum-systems are, for instance, contact faces for initial machining or fastening points. Datum systems can be defined for the entire model or for local features. Figure 4: Example for alignment by datum system 7 Creation of the drawing The document should include all necessary characteristic information for unambiguous component assessment. 7.1 Representation of the geometry The drawing geometry shall be derived from the 3D-CAD model only. 7.2 General tolerance In the proximity of the title block, the following data will be provided on the drawing: - JED-516 - Profile form symbol indicating the general tolerance for non-dimensioned features - Reference to the CAD model with indication of the revision code. Figure 5: Example for drawing entry acc. to JED-516
JED-516 : 2017-04 Page 4 7.3 Tolerancing of limited areas The user can select 3 local object surfaces or other features that clearly define the orientation of limited areas. These areas can be shown as dash-dotted lines. *) Figure 6: Alignment and tolerancing of limited area *) The reference to the valid CAD model is not required for restricted areas if it is already defined for the general tolerance according to this standard, see figure 7. 7.4 Technology information Indications that are relevant to the production and cannot be derived from the 3D-CAD model. For instance surface specifications, tolerances of form and position, material data, test and delivery specifications, pore and blowhole specifications shall be indicated in the drawing. Some areas may require high accuracy values that cannot be reached by scanning procedures, for instance: Functional areas Interfaces with other parts or customer equipment Rough part geometry in areas to be machined The dimensioning of these areas shall be provided in the drawing. In the selection of the dimensional tolerances, the relevant standards (ISO 8062, DIN 16742) shall be taken into account. The selected standard shall be indicated in the field General Specification provided in the drawing table. Thus, this standard will apply to all untoleranced dimensions. The determination of more accurate tolerances, beyond this standard, is made in cooperation with the supplier, the responsible engineer and the quality engineer. The measuring equipment used for the inspection of the part may have a limited capability of recording the geometry. For instance, optical scanners are unable to record deep pockets or bores. The measurement system s capability of recording the geometry has to be verified in cooperation with the quality engineer and the supplier. The sampling of geometry areas that cannot be recorded shall be measured individually. 8 Sampling The scope and execution of sampling is determined in cooperation of WABCO and the
JED-516 : 2017-04 Page 5 supplier. This agreement shall also include the geometry measurement procedure. The measurement of the component shall be verified against the valid 3D data model. The capability of the measuring system, in particular its capability of recording geometry and its accuracy, has to be proven. The number of measurement points shall be determined such as to allow the reliable assessment of all the relevant geometrical features. The datumsystem described shall be used for the assessment of the part. The following sequence of tolerances shall be observed in the verification of the geometry: 1. Tolerance of the dimensions indicated in the drawing 2. Tolerance in accordance with the selected tolerance indication on the basis of the present JED 9 Change management Any geometry modifications shall be made in the 3D model. In addition to the complete documentation, the supplier must receive the modified 3D-CAD model.
JED-516 : 2017-04 Page 6 Figure 7: Example for 3D documentation of a component according to JED-516