1、BRITISH STANDARD BS 4656-12: 1979 Incorporating Amendment No. 1 Specification for The accuracy of machine tools and methods of test Part 12: Dividing heads UDC 621.9.01187.001.4:621.9 589.8BS4656-12:1979 This British Standard, having been prepared under the directionof the Mechanical Engineering Sta
2、ndards Committee, was published underthe authority of the Executive Board and comes into effect on 28 September 1979 BSI 08-1999 First published September 1973 First revision September 1979 The following BSI references relate to the work on this standard: Committee reference MEE/6 Draft for comment
3、76/78120 DC ISBN 0 580 10908 9 Cooperating organizations The Mechanical Engineering Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: The organizations mark
4、ed with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Associated Offices Technical Committee Department of Trade (Marine Division) Association of Consulting Engineers Electricity Supply
5、Industry in England and Association of Hydraulic Equipment Wales Manufacturers Engineering Equipment Users Association Association of Mining Electrical and Federation of Manufacturers of Construction Mechanical Engineers Equipment and Cranes British Compressed Air Society Health and Safety Executive
6、 British Electrical and Allied Manufacturers Institution of Gas Engineers Association (BEAMA) Institution of Mechanical Engineers* British Gas Corporation Institution of Plant Engineers British Gear Manufacturers Association Institution of Production Engineers* British Internal Combustion Engine Llo
7、yds Register of Shipping Manufacturers Association London Transport Executive British Pump Manufacturers Association Machine Tool Industry Research Association* British Steel Corporation Ministry of Defence* British Steel Industry National Coal Board British Valve Manufacturers Association Oil Compa
8、nies Materials Association Chartered Institution of Building Services Process Plant Association Crown Agents for Oversea Governments and Railway Industry Association of Great Britain Administrations Society of Motor Manufacturers and Traders Department of Industry (Mechanical Limited Engineering)* T
9、elecommunication Engineering and Department of Industry (National Engineering Manufacturing Association (TEMA) Laboratory) Water-tube Boilermakers Association Department of the Environment Ball and Roller Bearing Manufacturers University of Aston in Birmingham Association University of Manchester In
10、stitute of Science Department of the Environment (PSA) and Technology Federation of British Engineers Tool Manufacturers Amendments issued since publication Amd. No. Date of issue Comments 5603 July 1988 Indicated by a sideline in the marginBS4656-12:1979 BSI 08-1999 i Contents Page Cooperating orga
11、nizations Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Application of test methods 1 4 Abbreviations 1 5 Diagrams 1 Table 1 Geometrical tests for dividing heads 2 Publication referred to Inside back coverBS4656-12:1979 ii BSI 08-1999 Foreword This Part of this British Standard has been
12、prepared under the direction of the Mechanical Engineering Standards Committee and implements agreements of the International Organization for Standardization (ISO). This edition supersedes BS4656-12:1973 which will be withdrawn on publication of this revised standard. This Part of the standard is t
13、echnically equivalent to ISO5734 “Test conditions of mechanical dividing heads for machine tools Testing of the accuracy”. This Part of the standard varies from ISO5734 in the following respects. Clauses. Clauses1 and3 contain the same information that is given in ISO5734 but they are expressed in a
14、ccordance with an accepted format that has been adopted for the BS4656 series of standards. Clauses4 and5 have been added. Inch dimensions. In accordance with the UK policy of metrication, inch dimensions given in ISO5734 have not been included in this British Standard. Tables. In column 6 ofTable 1
15、, a reference to ISO/R230 “Machine tool test code” has been replaced by a reference to BS3800. General. The qualification FIM (full indicator movement) has been added wherever run-out is measured. A British Standard does not purport to include all the necessary provisions of a contract. Users of Bri
16、tish Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1to 6, an inside back cover and a back cover
17、. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS4656-12:1979 BSI 08-1999 1 1 Scope This Part of this British Standard specifies, with reference to BS3800, geometrical tests for m
18、anually and power operated dividing heads and gives corresponding permissible deviations which apply. This standard is applicable to dividing heads of general purpose use and normal accuracy. It deals only with the verification of accuracy of the machine. It does not apply to the testing of the runn
19、ing of the machine (vibrations, abnormal noises, stick-slip motion of components, etc.) nor to its characteristics (speeds, feeds, etc.), which should generally be checked before testing accuracy. 2 References The title of the publication referred to in this standard is given on the inside back cove
20、r. 3 Application of test methods 3.1 In applying the tests detailed inTable 1, reference should be made to BS3800, especially concerning the installation of the machine before testing, warming up of spindles and other moving parts, the description of measuring methods and the recommended accuracy of
21、 testing equipment. 3.2 The tests may be applied in any order that is practicable and that makes for ease of mounting of instruments or gauging. The sequence in which the geometrical tests are listed inTable 1 is related to the sub-assemblies of the machine and it is not intended to impose the pract
22、ical order in which the tests are to be done. 3.3 It is not always necessary for all the tests specified in this standard to be carried out. The purchaser shall be at liberty to select, in agreement with the manufacturer, those tests relating to the properties that are of interest to him. The approp
23、riate tests are to be clearly stated when the machine is ordered. 3.4 When establishing the tolerance for a measuring range different from that given in this standard (see2.311 of BS3800:1964), it should be taken into consideration that the minimum value of tolerance is0.01mm for geometrical tests.
24、4 Abbreviations For the purposes of this standard, various methods of expressing permissible deviations are employed, each having a particular type of application. The methods employed are as follows. 5 Diagrams For reasons of simplicity the diagrams in this standard illustrate only one type of mach
25、ine. / This type of expression applies to deviations of perpendicularity that are ratios. for any length of This type of expression applies to deviations of straightness and parallelism, and is used in fact for local permissible deviations, the measurement length being obligatory. per This type of e
26、xpression applies to deviations of straightness and parallelism and is used to recommend a measurement length, but in this case the proportionality rule comes into operation if the measurement length differs from that indicated.BS 4656-12:1979 2 BSI 08-1999 Table 1 Geometrical tests for dividing hea
27、ds All dimensions are in millimetres 1 2 3 4 5 6 No. Diagram Object Permissible deviation Measuring instruments Observations and references to test code BS 3800 G1 Measurement of run-out of the internal taper of the spindle: (a) at the mouth of taper; (b) at a distance of300mm from the face of the s
28、pindle nose (a) 0.01 FIM (full indicator movement) (b) 0.02 FIM Dial guage and test mandrel 5.612.3 G2 Measurement of run-out of the nose of the centre 0.01 FIM Dial gauge 5.612.2 G3 (a) Measurement of run-out of the spindle external register diameter (b) Measurement of periodic axial slip (c) Measu
29、rement of camming of the face of the spindle nose (including periodic axial slip) (a) 0.01 FIM (b) 0.01 (c) 0.02 Dial gauge (a) 5.612.2 For a tapered spindle nose, the dial gauge shall be set perpendicular to the taper. (b) and (c) 5.62, 5.621.2, 5.622.1, 5.622.2 and 5.632 For the position of dial g
30、auge, see Figures59 to64 and 67, clauses5.62,5.622 and5.632. The value of the force F to be applied when carrying out checks (b) and (c) shall be specified by the manufacturerBS 4656-12:1979 BSI 08-1999 3Table 1 Geometrical tests for dividing heads All dimensions are in millimetres 1 2 3 4 5 6 No. D
31、iagram Object Permissible deviation Measuring instruments Observations and references to test code BS 3800 G4 Checking of squareness of the spindle axis with the supporting surface of the dividing head 0.02/300 a Dial gauge 5.512.1 Mount dial gauge on spindle. Set dividing head with spindle vertical
32、 by use of detent pin. Where there is no detent pin, set with dial gauge as shown in (a) so that the dial gauge reads zero when swung through180 . For all dividing heads readings should then be taken through360 of spindle rotation as shown in(b). The deviation is the largest difference between the r
33、eadings NOTEFor dividing heads fitted with detent pins to retain the spindle in the vertical position, the location provided by the detent pin is required to be verified. a Distance between the two points touched.BS 4656-12:1979 4 BSI 08-1999Table 1 Geometrical tests for dividing heads All dimension
34、s are in millimetres 1 2 3 4 5 6 No. Diagram Object Permissible deviation Measuring instruments Observations and references to test code BS 3800 G5 (a) Checking of parallelism of the locating tenon to the spindle axis (a) and (b) 0.015 for any measuring length of300 Dial gauge and test mandrel 5.412
35、.1 and 5.412.4 The measurement shall be carried out on two diametrically opposed generatrix of the mandrel, after the spindle has been rotated through180 . The tolerance is equal to the algebraic mean of the measurements. Tenons adjusted, if necessary (b) Checking of parallelism of the spindle axis
36、to the clamping surface NOTETest (b) is only necessary if location of spindle is by detent pin (c) Checking lateral offset of spindle with respect to central T-slot 0.015 5.442 Dial gauge is rotated through180 to touch each side of the test mandrel. Tenons adjusted if necessaryBS 4656-12:1979 BSI 08
37、-1999 5Table 1 Geometrical tests for dividing heads All dimensions are in millimetres 1 2 3 4 5 6 No. Diagram Object Permissible deviation Measuring instruments Observations and references to test code BS 3800 G6 Checking of maximum permissible dividing error: (a) in the output shaft rotation for on
38、e complete revolution of the input shaft (i.e. for a normal40/1 ratio dividing head a9 rotation is implied); (b) for any chosen angles of the output shaft. This test should be carried out for at least one angle situated in each of the four quadrants (a) 45 or maximum width of tolerance band of 1 30
39、of arc (b) 1 or maximum width of tolerance band of2 of arc Reference plate (a) 6.111 This test eliminates any error in the plate for the hole and pin type (b) 6.114 The permissible deviation includes the transmission errors in any type of dividing head as well as errors in the plate for the hole and
40、 pin type G7 (a) Checking of parallelism of the working axis with the median T-slot (a) 0.02 for any measuring length of:300 Dial gauge and test mandrel 5.412.4 Test mandrel held between centres: (a) tenons adjusted, if necessary; (b) Checking of parallelism of working axis with the clamping surface
41、 of the device (b) 0.02 for any measuring length of:300 (b) height adjusted, if necessary.6 blankBS4656-12:1979 BSI 08-1999 Publication referred to BS 3800, Methods for testing the accuracy of machine tools. BS 4656-12: 1979 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI
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