1、 Reference number ISO 4468:2009(E) ISO 2009INTERNATIONAL STANDARD ISO 4468 Second edition 2009-06-01 Gear hobs Accuracy requirements Fraises-mres Exigences dexactitude ISO 4468:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file
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6、1 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedISO 4468:2009(E) ISO 2009 All rights reserved iii Contents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Accuracy requirements 4
7、 5 Derivation of allowable values 5 5.1 General. 5 5.2 Tests 1-7 5 5.3 Tests 9, 11, 11A, 12, 12A 6 5.4 Test 9B . 6 5.5 Tests 8, 8A, 9B, 10, 13, 14, 15 and 16 6 Bibliography . 32 ISO 4468:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a wor
8、ldwide 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
9、 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
10、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 Standar
11、d 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 4468 was prepared by Te
12、chnical Committee ISO/TC 60, Gears, Subcommittee SC 1, Nomenclature and wormgearing. This second edition cancels and replaces the first edition (ISO 4468:1982), which has been technically revised. INTERNATIONAL STANDARD ISO 4468:2009(E) ISO 2009 All rights reserved 1 Gear hobs Accuracy requirements
13、1 Scope This International Standard specifies requirements for the accuracy of general-purpose hobs of 0,5 module to 40 module. These hobs are intended for producing gears which conform to ISO 53 and ISO 54. This International Standard applies to hobs for spur and helical gears. It applies to solid
14、(monobloc) and inserted blade hobs. The elemental features of hobs are graded according to accuracy, as follows: Grade 4A; Grade 3A; Grade 2A: Grade A; Grade B; Grade C; Grade D. Grade 4A is the highest order of precision. In addition to the elemental tests for hobs, this International Standard give
15、s permitted tolerances for composite tests that are taken along the cutting edges on the line of action. The two groups of tests are not equivalent and one shall choose between one or the other. If there was no previous agreement, the hob is regarded as belonging to the precision class specified if
16、it satisfies one or the other of the two methods of inspection. NOTE The tolerances in this International Standard were determined for gear hobs whose dimensions conform to ISO 2490, but with certain precautions they can be applied to hobs not specified in this International Standard. 2 Normative re
17、ferences 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 53, Cylindrical gears for general an
18、d heavy engineering Standard basic rack tooth profile ISO 54, Cylindrical gears for general engineering and for heavy engineering Modules ISO 4468:2009(E) 2 ISO 2009 All rights reservedISO 286-2, ISO system of limits and fits Part 2: Tables of standard tolerance grades and limit deviations for holes
19、 and shafts ISO 1122-1, Vocabulary of gear terms Part 1: Definitions related to geometry ISO 2490, Solid (monobloc) gear hobs with tenon drive or axial keyway, 0,5 to 40 module Nominal dimensions 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 1122-1
20、 and the following apply. 3.1 radial runout of hub diameter total deviation in radial distance of the hub periphery from the axis 3.2 axial runout of hub face total axial deviation of the hub face from a true plane of rotation 3.3 radial runout of tips of teeth total deviation in the radial distance
21、 from the axis to the tips of the hob teeth 3.4 straightness and radial alignment over cutting depth angular relationship between the tooth face and a radial line intersecting the tooth face at the hob outside diameter, measured in a plane perpendicular to the axis 3.5 adjacent spacing of cutting fa
22、ce of gashes maximum deviation between any two consecutive cutting face measurements 3.6 total spacing of cutting face of gashes maximum deviation between any two cutting face measurements 3.7 gash lead deviation per 100 mm maximum deviation as the probe contacts the tooth faces within axial region
23、of the gash NOTE Allowable values for deviations are given per 100 mm of cutting face width. 3.8 tooth profile deviation maximum deviation of that portion of the hob tooth that generates an unmodified involute profile 3.8.1 tooth profile deviation when line of action test is used maximum deviation o
24、f that portion of the hob tooth that generates an unmodified involute profile when the line of action test is used NOTE Test 8A is used for tooth profile deviation when the line of action test is used. ISO 4468:2009(E) ISO 2009 All rights reserved 3 3.9 tooth thickness normal tooth thickness differe
25、nce of actual and reference datum at the reference cylinder NOTE Negative only. 3.9.1 addendum difference of addendum values related to designed normal tooth thickness observed during testing NOTE Positive only. Test 9A is used for addendum. 3.9.2 tooth thickness difference along one gash difference
26、 between maximum and minimum nominal tooth thickness along one gash at the reference cylinder NOTE Test 9B is used for tooth thickness difference along one gash. This test is only valid for quality Grades 4A, 3A and 2A. 3.10 lead deviation on adjacent teeth maximum lead deviation between any two con
27、secutive teeth 3.11 lead deviation in one axial pitch maximum deviation between any two teeth within any group of consecutive teeth contained in one axial pitch; the number of teeth in one axial pitch is the number of teeth encountered by the measurement probe as it moves parallel to the reference a
28、xis during lead testing for a distance of one axial pitch of the hob NOTE The number of teeth is determined by the number of gashes, the number of threads and, in the case of helical gash hobs, the gash lead. 3.11.1 lead deviation in one axial pitch when line of action test is used maximum deviation
29、 between any two teeth within any group of consecutive teeth contained in one axial pitch when the line of action test is used NOTE Test 11A is used for lead deviation in one axial pitch when the line of action test is used. 3.12 lead deviation in three axial pitches maximum lead deviation between a
30、ny two teeth contained in three axial pitches; the number of teeth in three axial pitches is that number of teeth encountered by the measurement probe as it moves parallel to the reference axis during lead testing for a distance of three axial pitches of the hob NOTE The number of teeth is determine
31、d by the number of gashes, the number of threads and, in the case of helical gash hobs, the gash lead. 3.12.1 lead deviation in three axial pitches when line of action test is used maximum lead deviation between any two teeth contained in three axial pitches when the line of action test is used NOTE
32、 Test 12A is used for lead deviation in three axial pitches when the line of action test is used. ISO 4468:2009(E) 4 ISO 2009 All rights reserved3.13 adjacent deviation along line of action maximum deviation between any two consecutive teeth of a given line of action test NOTE 1 Adjacent hob line of
33、 action allowable deviation can be applied to adjacent line of action test results in those cases where the hob has been specified to be manufactured with involute helicoid geometry. NOTE 2 Adjacent deviation along the line of action is measured at the cutting edge. 3.14 total deviation along line o
34、f action total maximum deviation between any two teeth of a given line of action test NOTE 1 Total hob line of action allowable deviation can be applied to total line of action test results in those cases where the hob has been specified to be manufactured with involute helicoid geometry. NOTE 2 Tot
35、al deviation along the line of action is measured at the cutting edge. 3.15 axial pitch deviation from thread to thread maximum axial pitch deviation between any two consecutive teeth contained within two gashes NOTE 1 For an odd number of threads, the angle between the gashes is approximately 90. F
36、or an even number of threads, it is approximately 120. NOTE 2 The minimum requirement is to inspect the number of axial pitches equal to the number of threads. 3.16 axial pitch deviation in any three axial pitches over all threads maximum axial pitch deviation over any three adjacent teeth contained
37、 within two gashes NOTE 1 For an odd number of threads, the angle between the gashes is approximately 90. For an even number of threads, it is approximately 120. NOTE 2 The minimum requirement is to inspect the number of axial pitches equal to the number of threads. 4 Accuracy requirements Hobs shal
38、l conform to the requirements of Tables 2 and 4, as appropriate. When prior agreement between the hob manufacturer and purchaser specifies measurement of hobs, the manufacturer should select: the measurement method to be used from among the applicable methods described in this International Standard
39、 and summarized in Table 1; the piece of measurement equipment to be used by the selected measurement method, provided it is in proper calibration; the individual teeth to be measured, as long as they are approximately equally spaced. No particular method of measurement or documentation is considere
40、d mandatory. When applications require measurements beyond those recommended in this International Standard, it is recommended to negotiate special measurement methods prior to manufacturing the hob. ISO 4468:2009(E) ISO 2009 All rights reserved 5 Table 1 Reference for measurement methods Test numbe
41、raTest method definition Test description Elemental test Composite testb 3.1 Radial runout of hub diameter 1 1 3.2 Axial runout of hub face 2 2 3.3 Radial runout of tips of teeth 3 3 3.4 Straightness and radial alignment over cutting depth 4 4 3.5 Adjacent spacing of cutting face of gashes 5 5 3.6 T
42、otal spacing of cutting face of gashes 6 6 3.7 Gash lead deviation per 100 mm 7 7 3.8 Tooth profile deviation 8 8A 3.9 Tooth thickness 9 or 9A and 9B 9 or 9A and 9B 3.10 Lead deviation on adjacent teeth 10 10 3.11 Lead deviation in one axial pitch 11 11A 3.12 Lead deviation in three axial pitches 12
43、 12A 3.13 Adjacent deviation along line of action (measured at the cutting edge) c13 3.14 Total deviation along line of action (measured at the cutting edge) c14 3.15 Axial pitch deviation from thread to thread 15 15 3.16 Axial pitch deviation in any three axial pitches over all threads 16 16 aSee C
44、lause 5. bSelect the composite test when the line of action test is used. cTest does not apply to the elemental method. 5 Derivation of allowable values 5.1 General Test 7 does not conform to a datum value and is not among the statements in Clause 5 concerning grade relationships. With the exception
45、 of Test 7, the datum from which all the values in Table 6 are derived is the value of 45 m Test 14 Grade A modules 16 to 25. 5.2 Tests 1-7 For tests 1 to 7, use Equation (1): Calculated value = 45 K eK mK g(1) K tis not used. ISO 4468:2009(E) 6 ISO 2009 All rights reserved5.3 Tests 9, 11, 11A, 12,
46、12A For tests 9, 11, 11A, 12, 12A, use Equation (2): Calculated value = 45 K eK mK gK t(2) where K eis the ratio for test element (see Table 3); K mis the ratio for division of module (see Table 4); K gis the ratio for grade (see Table 3); K tis the ratio for number of threads (see Table 5). 5.4 Tes
47、t 9B Test 9B is only valid for quality Grades 4A, 3A and 2A. 5.5 Tests 8, 8A, 9B, 10, 13, 14, 15 and 16 Tests 8, 8A, 9B, 10, 13, 14, 15 and 16 are only valid for the following: a) 1-thread, all Module ranges; b) 2-threads, Module range 0,5 u m u 16; c) 3- and 4-threads, Module range 0,5 u m u 6; d)
48、5-, 6- and 7-threads, Module range 0,5 u m u 3,5. The value of the allowable deviations has been rounded to the nearest whole value after calculation. The minimum value of allowable deviations is 2 m. Standard bores shall be finished straight and parallel within the tolerances given in Table 2 for 7
49、5 % of each bearing length for Grades 4A, 3A, 2A, A and B hobs and 50 % for Grades C and D hobs. A reference mandrel of nominal bore diameter shall pass through the bore as a check of alignment. The tolerances on bore diameter are specified in Table 2. ISO 4468:2009(E) ISO 2009 All rights reserved 7 Table 2 Tolerance on bores ToleranceaDatum diameter mm Grade of hob 8 10 13 22 27 32 40 50 60 80 4A H3 3A 2A H3 H4 A H4 H5 B H5 C D H6 aIn accordance with ISO 286-2. Table 3 Ratio for test element a
