1、BRITISH STANDARD BS 3884-3: 1990 ISO 8526-2: 1990 Incorporating Amendment No. 1 Modular units for machine tools Part 3: Specification for workholding pallets over 800 mm nominal sizeBS3884-3:1990 This British Standard, having been prepared under the direction of the Machine, Engineers and Hand Tools
2、 Standards Policy Committee, was published under the authority of the Board of BSI andcomes into effect on 30November1990 BSI 10-1999 First published as BS3884 April1974 Second edition November1990 The following BSI references relate to the work on this standard: Committee reference MTE/1 Draft for
3、comment 88/70735 DC ISBN 0 580 19170 2 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Machine, Engineers and Hand Tools Standards Policy Committee (MTE/-) to Technical Committee MTE/1, upon which the following bodies were represented: A
4、dvanced Manufacturing Technology Research Institute Cranfield Institute of Technology Department of Trade and Industry Mechanical Engineering and Manufacturing Technology Division (Mmt) Health and Safety Executive Ministry of Defence Coopted members Amendments issued since publication Amd. No. Date
5、Comments 7634 May 1993 Indicated by a sideline in the marginBS3884-3:1990 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 1 2 Normative references 1 3 Terminology 1 4 Dimensions 1 5 Top surface 1 6 Location of workpiece 2 7 Bottom surface 2 8 Design
6、ation of pallets 2 Annex A (normative) Top surfaces with radial T-slots Types 5 and 6 11 Annex B (informative) Principle of arithmetic and geometric progressionsapplied to T-slot pitches 13 Figure 1 Workholding pallet 1 Figure 2 Types of top surface 3 Figure 3 Principal dimensions of workholding pal
7、lets 5 Figure 4 Details of edge locators 9 Figure 5 Fixing holes for latch mechanism 10 Figure A.1 Top surface, type 5 with radial T-slots 11 Figure A.2 Top surface, type 6 with twin radial T-slots 12 Figure B.1 Pallets with an arithmetic progression of the T-slot pitches 13 Figure B.2 Pallets with
8、a geometric progression of the T-slot pitches 14 Table 1 Terminology 1 Table 2 Dimensions of workholding pallets 7 Table 3 Dimensions of edge locators 10 Table 4 Dimensions of fixing holes for latch mechanism 10 Publication(s) referred to Inside back coverBS3884-3:1990 ii BSI 10-1999 National forewo
9、rd This Part of BS3884 has been prepared under the direction of the Machine, Engineers and Hand Tools Standards Policy Committee and implements agreements of the International Organization for Standardization (ISO). It is identical with ISO8526 “Modular units for machine tools Workholding pallets ”
10、Part 2:1990 “Workholding pallets of nominal size greater than800mm”. The Technical Committee has reviewed the provisions of ISO299:1987 and ISO1101:1983, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. A related British Stan
11、dard to ISO299 is BS2485:1987 “Specification for tee slots, tee bolts, tee nuts and tenons”. A related British Standard to ISO1101 is BS308 “Engineering drawing practice” Part 3:1972 “Geometrical tolerancing”. The introduction to ISO8526-2 reads as follows. “This part of ISO8526 has been drawn up to
12、 facilitate interchangeability of workholding pallets, including those from different manufacturers. It deals with square pallets and rectangular pallets of length-to-width ratio of1,25and of nominal size greater than800mm. If pallets with tighter tolerances than specified in this part of ISO8526 ar
13、e required, they shall be subject to agreement between the manufacturer and the user. This part of ISO8526 does not specify the positioning accuracy of the pallets.” A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible
14、for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International Standard Corresponding British Standard ISO 286-2:1988 BS 4500 ISO limits and fits Section 1.2:1990 Tables of commonly used tolerance grades and
15、 limit deviations for holes and shafts (Identical) ISO 2768:1989 Part 3:1973 Working limits on untoleranced dimensions (Technically equivalent) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 14, an inside back cover and a back cover. This sta
16、ndard 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.BS3884-3:1990 BSI 10-1999 1 1 Scope This part of ISO8526 specifies the dimensions of workholding pallets for use with machine tools and in man
17、ufacturing systems. It applies to the following nominal sizes of pallet: 1000mm, 1250mm, 1600mm and 2000mm 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO8526. At the time of publication, the editions
18、indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO8526 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid Inter
19、national Standards. ISO 286-2:1988, ISO system of limits and fits Part2: Tables of standard tolerance grades and limit deviations for holes and shafts. ISO 299:1987, Machine tool tables T-slots and corresponding bolts. ISO 1101:1983, Technical drawings Geometrical tolerancing Tolerancing of form, or
20、ientation, location and run-out Generalities, definitions, symbols, indications on drawings. ISO 2768-1:1989, General tolerances Part1:Tolerances for linear and angular dimensions without individual tolerance indications. 3 Terminology 3.1 Nominal size The nominal size is given by dimension a 1seeFi
21、gure 3 a). 3.2 General The terms used for the purposes of this part of ISO8526 are listed inTable 1 and illustrated inFigure 1. Table 1 Terminology 4 Dimensions Dimensions of pallets are given inTable 2. 5 Top surface 5.1 Corners Corners shall be removed from pallets (seedimension c inTable 2). Refe
22、rence number Designation 1 Top surface of pallet 2 Centre hole 3 Location surface 4 Clamping surface 5 Transportation slide surface 6 Location hole 7 Edge locator (when fitted) 8 Alignment hole (when provided) 9 Fixing holes for latch mechanism 10 Resting surface Figure 1 Workholding palletBS3884-3:
23、1990 2 BSI 10-1999 5.2 T-slots and threaded holes Either T-slots or threaded holes may be provided in the top surface. Pitches of threaded holes and T-slots and T-slot dimensions shall comply with ISO299. Dimensions and pitches of T-slots and threaded holes are given inTable 2. NOTE 1The top surface
24、 may be left plain, if desired, for special applications. NOTE 2Radial slots may be used for special applications. Their dimensions are given inAnnex A, Figure A.1 and Figure A.2. 5.3 Types of top surface The different types of top surface are as follows: type1: surface with threaded holes seeFigure
25、 2 a); type2: surface with T-slots seeFigure 2 b); type3: surface with T-slots and cross-tenons seeFigure 2 c); type4: plain surface (seeFigure 5); type5: surface with radial T-slots (seeFigure A.1); type6: surface with twin radial T-slots (seeFigure A.2). 5.4 Centre hole A centre hole shall be prov
26、ided and may be used as a reference hole for work positioning on the pallet and/or as a reference hole for pallet manufacturing (seeFigure 1). The depth of the counterbore, d 4 , if present, shall always be greater than the depth of the central tenon slot of the pallet. 5.5 Alignment hole An alignme
27、nt hole, d 6 , may be provided for use in positioning the workpiece or fixture on the pallet and/or as a reference hole for pallet manufacturing purposes (seeFigure 1). NOTEIt is necessary to provide means of preventing ingress of swarf and coolant to the bottom surface. 6 Location of workpiece Work
28、pieces or fixtures shall be located on the top surface by one of the following methods: a) by means of edge locators (seeFigure 4 andTable 3); NOTEFor type2and type3top surfaces, the mounting holes for the edge locators are at the discretion of the manufacturer. The positions of the fixing holes for
29、 the fixture should be the same as those shown inFigure 4. b) by means of a centre hole and an associated alignment hole (where the top surface of the pallet has threaded holes) seeFigure 2 a); c) by means of a centre hole and a reference slot (where the top surface of the pallet has T-slots) see Fi
30、gure 2 b); d) by means of two perpendicular tenon (crossed-tenon) slots seeFigure 2 c); e) by means of two or three straight-through location holes, d 6seeFigure 3 a) andFigure 3 b). NOTE 1It is necessary to provide means of preventing ingress of swarf and coolant to the bottom surface. NOTE 2The st
31、raight-through feature is optional. 7 Bottom surface 7.1 Location of pallet on the receiver (on the machine tool) Location of the pallet on the receiver shall be by means of one of the following methods (seeFigure 3): a) by two cylindrical holes on the pallet seeFigure 3 a) and two cylindrical pins
32、on the receiver; b) by two or three tapered holes on the pallet seeFigure 3 b) and two or three tapered pins on the receiver. 7.2 Shape and dimensions The shape and dimensions of the bottom surface are given inFigure 3 a) andTable 2. 8 Designation of pallets The designation of a pallet is given by t
33、he number of this part of ISO8526; its nominal size and length, a 1 a 1or a 1 a 2 ; its top surface type (see5.3); the pitch of its T-slots or threaded holes; the method of workpiece location seeclause6, a) to e); the method of locating the pallet on the receiver see7.1, a) and b). EXAMPLE Designati
34、on of a square pallet, of nominal size and length1000 1000, with top surface type2, with100mm pitch of T-slots, with workpiece location by means of centre hole and reference slotc), and pallet location on the receiver by means of cylindrical holes a): ISO8526-21000 1000-2-100-c-a EXAMPLE Designation
35、 of a rectangular pallet, of nominal size and length 1000 1250, with top surface type2, with100mm pitch of T-slots, with workpiece location by means of centre hole and reference slot c), and pallet location on the receiver by means of tapered holes b): ISO8526-21000 1250-2-100-c-bBS3884-3:1990 BSI 1
36、0-1999 3 Figure 2 Types of top surface (continued)BS3884-3:1990 4 BSI 10-1999 NOTEFor the tolerancing of location and orientation, see ISO1101. Figure 2 Types of top surface (concluded)BS3884-3:1990 BSI 10-1999 5 NOTEFor tapered location holes, seeFigure 3 b). a) Workholding pallets with cylindrical
37、 location holes Figure 3 Principal dimensions of workholding pallets (continued)BS3884-3:1990 6 BSI 10-1999 *) The tolerances on t 3 , 15 and 30 are as specified by the manufacturer. b) Workholding pallets with tapered location holes NOTE 1The type of location required should be stated when ordering
38、 pallets. NOTE 2For the tolerancing of form, orientation and location, see ISO1101. NOTE 3Bushes of minimum depth equal to11/4 times their diameter may be inserted at either end of d 6 , if preferred. NOTE 4Where d 6is straight through, the centre portion of the bore of d 6may be relieved to a maxim
39、um length of (h 2 40) 2,5 d 6 , if desired. Figure 3 Principal dimensions of workholding palletsBS3884-3:1990 BSI 10-1999 7 Table 2 Dimensions of workholding pallets a(seeFigure 2 andFigure 3) Dimensions in millimetres Dimension Nominal size and length a 1 a 1 a 1 a 2 a 1 a 1 a 1 a 2 a 1 a 1 a 1 a 2
40、 a 1 a 1 a 1 a 2 1 000 1000 1 000 1250 1 250 1250 1 250 1600 1 600 1600 1 600 2000 2 000 2000 2 000 2500 b 1900 1 110 1 400 1 700 b 2840 1 030 1 300 1 580 b 3 0,5 630 800 1 000 1 250 c b 125 125 c 200 250 d 11 250 1 600 2 000 2 500 d 21 458 1 886 2 332 2 916 d 3H7 d 50 80 80 80 d 4(optional) 110 110
41、 110 110 d 5H7 d,e 100 100 100 100 d 6H7 d,f 25 25 25 25 d 7 g M20 M20 M24 M24 d 8 g 22 22 26 26 d 9 55 55 55 55 d 10 50 80 80 80 e 1 400 500 675 875 e 2 0,01 800 1 000 1 350 1 750 h 1 0,5 200 230 260 290 h 2 190 0,02 220 0,03 250 0,04 280 0,04 h 3 0,5 140 170 200 230 h 4125 155 185 215 l 1 0,025 40
42、0 500 675 875 l 2 h AP 100 100 200 200 GP 100 125 160 200 l 3 h AP 100 100 200 200 GP 100 125 160 200 0 0,5 +1 0 0 5 0 5 0 0,5BS3884-3:1990 8 BSI 10-1999 Table 2 Dimensions of workholding pallets a(seeFigure 2 andFigure 3) Dimensions in millimetres Dimension Nominal size and length a 1 a 1 a 1 a 2 a
43、 1 a 1 a 1 a 2 a 1 a 1 a 1 a 2 a 1 a 1 a 1 a 2 1 000 1000 1 000 1250 1 250 1250 1 250 1600 1 600 1600 1 600 2000 2 000 2000 2 000 2500 m i 22 22 28 28 n 38 38 48 48 t 1 35 35 40 40 t 2 12 12 12 12 t 3 2,67 2,67 2,67 2,67 a For working limits on untoleranced dimensions, see the medium series of ISO27
44、68-1. b Chamfer 45 or radius at choice of the manufacturer. c Temporary. d See ISO 286-2. e The centre hole may have a bush in the reference bore. f When d 6is used as an alignment hole on the top surface and does not go straight through, the depth is at the manufacturers discretion. When d 6is used
45、 purely as a clearance hole, it need not be toleranced. g The recess dimensions, d 8 0,5, associated with the tapped holes in the top surface are primarily for thread protection. Headed plugs may be inserted in exposed holes to prevent the ingress of swarf, in which case the recess dimensions may be
46、 modified to accommodate the heads of the plugs. The use of plain plugs does not necessitate a change in these dimensions. The dimensions of plugs have not been standardized. Therefore such dimensions are left to agreement between purchaser and manufacturer. h AP and GP dimensions are alternative va
47、lues, where AP is the arithmetic progression and GP is the geometric progression. (SeeAnnex B.) i The tolerance on m is H8 for tenon slots and H12 for fixing slots. +1 0 +1 0BS3884-3:1990 BSI 10-1999 9 In this new figure, the dimensions20mm and40mm specified for the two edge locators shown at the lo
48、wer right replace the former dimensions18mm and36mm respectively, and hence correspond to the dimensions specified at the upper left. Figure 4 Details of edge locators (when fitted)BS3884-3:1990 10 BSI 10-1999 Table 3 Dimensions of edge locators (when fitted) Table 4 Dimensions of fixing holes for l
49、atch mechanism Dimensions in millimetres Nominal size of pallet a 1 L 1 0,01 L 2 L 3 L 4 L 5 L 6 L 7 L 8 0,01 H 1 H 2 D 1 D 2 Fixing screw in pallet 1 000 500 200 50 98 250 38 21 625 100 30 22 33 M20 1 250 625 250 50 98 315 38 21 800 100 30 22 33 M20 1 600 800 315 55 108 400 45 25 1 000 120 35 26 36 M24 2 000 1 000 400 55 108 500 45 25 1 250 120 35 26 36 M24
