ISO-8636-2-2007.pdf

Reference number ISO 8636-2:2007(E) © ISO 2007 INTERNATIONAL STANDARD ISO 8636-2 Second edition 2007-12-15 Machine tools Test conditions for bridge-type milling machines Testing of the accuracy Part 2: Travelling bridge (gantry-type) machines Machines-outils Conditions d'essai des machines à fraiser à portique Contrôle de l'exactitude Partie 2: Machines à portique mobile ISO 8636-2:2007(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. 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ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii © ISO 2007 All rights reserved ISO 8636-2:2007(E) © ISO 2007 All rights reserved iii Contents Page Foreword iv 1 Scope . 1 2 Normative references. 1 3 Terms and definitions. 1 4 Classification and description of travelling bridge (gantry-type) milling machines . 2 4.1 Classification. 2 4.2 Descriptions of principal components. 2 5 Terminology and designation of axes 3 5.1 Terminology 3 5.2 Designation of axes 3 6 Preliminary remarks . 6 6.1 Measuring units 6 6.2 Reference to ISO 230-1. 6 6.3 Temperature conditions. 6 6.4 Testing sequence 8 6.5 Tests to be performed 8 6.6 Measuring instruments 8 6.7 Minimum tolerance. 8 6.8 Machining tests. 8 6.9 Positioning tests. 8 7 Geometric tests. 8 7.1 Axes of motion 9 7.2 Table. 17 7.3 Milling head. 20 7.4 Swivelling milling head 23 7.5 Horizontal milling head (side milling head) . 24 8 Machining tests. 27 8.1 Flatness of test pieces by slab milling. 27 8.2 Milling of lateral face 28 9 Accuracy and repeatability of positioning of numerical control axes 29 9.1 Linear axes 29 9.2 Rotary axes 35 10 Geometric accuracy of axes of rotation of toolholding spindles 36 Bibliography. 38 -,-,- ISO 8636-2:2007(E) iv © ISO 2007 All rights reserved Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 8636-2 was prepared by Technical Committee ISO/TC 39, Machine tools, Subcommittee SC 2, Test conditions for metal cutting machine tools. This second edition cancels and replaces the first edition (ISO 8636-2:1988) which has been technically revised. Especially, a) geometrical tests have been rearranged; the new G numbers compared to the old ones are given in the following table: ISO 8636-2:2007 1 2(add) 3 4(add) 5 6 7 8 9 10 11 12 ISO 8636-2:1988 2 8 10 9 6 5 1 4 c) tolerances on accuracy and repeatability of positioning have been changed in accordance with ISO 230-2:2006; d) new test for geometric accuracy of axes of rotation of workholding spindles (R1) has been added. The actual deviations of all parameters are shown as test results, but the tolerances are limited only to certain parameters. ISO 8636 consists of the following parts, under the general title Machine tools Test conditions for bridge-type milling machines Testing of the accuracy: Part 1: Fixed bridge (portal-type) machines Part 2: Travelling bridge (gantry-type) machines -,-,- INTERNATIONAL STANDARD ISO 8636-2:2007(E) © ISO 2007 All rights reserved 1 Machine tools Test conditions for bridge-type milling machines Testing of the accuracy Part 2: Travelling bridge (gantry-type) machines 1 Scope This part of ISO 8636 specifies, with reference to ISO 230-1, ISO 230-2, and ISO 230-7, geometric tests, machining tests, and tests for checking accuracy and repeatability of positioning of numerically controlled axes for general-purpose normal accuracy bridge-type milling machines with a travelling bridge (gantry-type). This part of ISO 8636 also specifies the applicable tolerances corresponding to the above-mentioned tests. This part of ISO 8636 is applicable to machines with travelling bridge and fixed table. It does not include single-column (open sided) machines and those with fixed bridge and moving tables. This part of ISO 8636 deals only with the verification of the accuracy of the machine. It does not apply to the testing of the machine operation (vibration, abnormal noise, stick-slip motion of components, etc.) nor to machine characteristics (such as speeds, feeds, etc.), which should generally be checked before testing the accuracy. This part of ISO 8636 provides the terminology used for the principal components of the machines and the designation of the axes with reference to ISO 841. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 230-1:1996, Test code for machine tools Part 1: Geometric accuracy of machines operating under no-load or finishing conditions ISO 230-2:2006, Test code for machine tools Part 2: Determination of accuracy and repeatability of positioning numerically controlled axes ISO 230-7:2006, Test code for machine tools Part 7: Geometric accuracy of axes of rotation 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 milling operation machining operation, which consists of removing material by means of a rotary tool (milling cutter), of which there are several different types NOTE Typical milling operations mostly involve face milling or end milling. The tools are mounted either in the spindle taper or on the spindle front face. ISO 8636-2:2007(E) 2 © ISO 2007 All rights reserved 3.2 boring operation operation which consists of machining the diameters of cylindrical, conical, blind or through-holes to the required size 3.3 drilling tapping operation operation to produce blind or through-holes 3.4 travelling bridge (gantry-type) milling machine milling machine with one fixed workpiece-holding table, two slideways on either side of the table, and a travelling bridge (gantry) on which the milling head(s) are mounted NOTE 1 The slideways may or may not be independent of the table. NOTE 2 The gantry, composed of a left-hand column and a right-hand column supported by respective column slides and made integral with a fixed top bridge, is moved along the bed slideways. The gantry supports a horizontal cross-rail, movable or fixed in the vertical plane, on which one or more milling heads are mounted with vertical or inclinable spindles. 4 Classification and description of travelling bridge (gantry-type) milling machines 4.1 Classification These machines are classified into the following types depending upon construction: travelling bridge (gantry-type) milling machines with fixed cross-rail; travelling bridge (gantry-type) milling machines with movable cross-rail (see Figure 1). 4.2 Descriptions of principal components The principal components of these machines are described in Figure 1. 4.2.1 Bed and table The worktable (1) is located between two slideways that form the bed. The worktable and the slideways can be constructed in one piece. Alternatively, the assembly may be made of several pieces rigidly connected through the foundation or directly to each other. NOTE The table can be replaced by a floorplate. 4.2.2 Columns, top bridge and cross-rail The columns (9) and (10) are rigid parts with vertical slideways, which either slide on the bed or are fixed rigidly to column slides (7) and (8) which slide horizontally on the bed. The top bridge (11) is a fixed part connecting the two columns near their top ends. The cross-rail (14) is a part whose horizontal slideways are parallel to the plane of the table. In the case of machines with fixed cross-rails, the cross-rail is made integral with the columns and may be used as a top bridge. In the case of machines with movable cross-rails, the cross-rail slides vertically on the slideways of the columns (12) and (13). One or more milling heads with vertical, horizontal or inclinable spindles are mounted on the cross-rail slideways. -,-,- ISO 8636-2:2007(E) © ISO 2007 All rights reserved 3 4.2.3 Milling head(s) Milling heads (16) and (20) are mounted on head saddles (15) and (21) which move on the cross-rail or column slideways. The portion in direct contact with the cross-rail slideways is called the vertical head saddle (15). The milling head may be mounted so that it slides on the vertical head saddle in the direction of the spindle axis; it is then called a ram. The spindle may be mounted in a quill sliding in the milling head in the direction of the spindle axis. Some parts of the head may be inclinable. 4.2.4 Cutting motion Cutting motion is provided by the spindles and drive mechanisms of the milling heads. 4.2.5 Feed motion The following feed movements may be provided with a constant or variable feed rate: horizontal movement of the movable gantry; vertical movement of the movable cross-rail; horizontal movement of the milling heads; vertical movement of rams, if any; rotational movement (tilt movements of milling heads). NOTE 1 In general, rapid traverse is available in addition to feed movement. NOTE 2 The vertical movement of the movable cross-rail can be either a feed movement (in which case the cross-rail is said to be movable when working) or a movement between fixed working positions (the cross-rail is then said to be movable when being positioned). 5 Terminology and designation of axes 5.1 Terminology See Figure 1 and Table 1. 5.2 Designation of axes See Figures 1 to 4. -,-,- ISO 8636-2:2007(E) 4 © ISO 2007 All rights reserved Figure 1 Travelling bridge (gantry-type) machine with movable cross-rail (see Table 1) Figure 2 Machine with one milling head -,-,- ISO 8636-2:2007(E) © ISO 2007 All rights reserved 5 Table 1 Terminology Ref. English French German 1 Table (or floorplate) Table (ou taque) Tisch (oder Bodenplatte) 2 Clamping surface Surface de bridage Aufspannfläche 3 Left-hand part of the bed Banc gauche Linker Teil des Maschinenbetts 4 Right-hand part of the bed Banc droit Rechter Teil des Maschinenbetts 5 Left-hand bed slideways Glissières du banc gauche Linke Bett-Führungsbahnen 6 Right-hand bed slideways Glissières du banc droit Rechte Bett-Führungsbahnen 7 Left-hand column slide Chariot porte-montant gauche Linker Ständerschlitten 8 Right-hand column slide Chariot porte-montant droit Rechter Ständerschlitten 9 Left-hand column Montant gauche Linker Ständer 10 Right-hand column Montant droit Rechter Ständer 11 Top bridge Entretoise Querbalken 12 Left-hand column slideways Glissières du montant gauche Linke Ständer-Führungsbahnen 13 Right-hand column slideways Glissières du montant droit Rechte Ständer-Führungsbahnen 14 Cross-rail (movable or fixed) Traverse (mobile ou fixe) Traverse (beweglich oder fest) 15 Vertical head saddle Chariot porte-outils vertical Senkrechter Spindelstockschlitten 16 Vertical milling head Tête de fraisage verticale Senkrechter Fräskopf 17 Quill (ram) Fourreau (coulant) Traghülse (Pinole) 18 Milling spindle Broche porte-fraise Frässpindel 19 Tool (milling cutter) Outil (fraise) Werkzeug (Fräser) 20 Horizontal milling head Tête de fraisage horizontale Waagerechter Fräskopf 21 Horizontal head saddle Chariot porte-outils horizontal Waagerechter Spindelstockschlitten 22 Reference T-slot Rainure à T de référence Referenz T-Nut -,-,- ISO 8636-2:2007(E) 6 © ISO 2007 All rights reserved Figure 3 Machine with one milling head swivelling on axes C and A 6 Preliminary remarks 6.1 Measuring units In this part of ISO 8636, all linear dimensions, deviations and corresponding tolerances are expressed in millimetres; angular dimensions are expressed in degrees, and angular deviations and the corresponding tolerances are primarily expressed in ratios (e.g. 0,00x/1 000), but in some cases microradians (µrad) or arcseconds () may be used for clarification purposes. The equivalence of the following expressions should always be kept in mind: 0,010/1 000 = 10 µrad 2 6.2 Reference to ISO 230-1, ISO 230-2, and ISO 230-7 To apply this part of ISO 8636, reference shall be made to ISO 230-1, especially for the installation of the machine before testing, warming up of the spindle and other moving components, description of measuring methods and recommended accuracy of testing equipment. In the “Observations” box of the tests described in the following clauses, the instructions are preceded by a reference to the corresponding clause in ISO 230-1, ISO 230-2 or ISO 230-7 in cases