1、BRITISH STANDARD BS 7708:1993 ISO 9189:1993 Specification for Power presses, mechanical straight-sided high-speed type of 250 kN up to 4000 kN nominal force UDC 621.979BS 7708:1993 This British Standard, having been prepared under the directionof the Machine, Engineers and Hand Tools Standards Polic
2、y Committee, waspublished under the authorityof the Standards Boardand comes into effect on 15 October 1993 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference MTE/1 Draft for comment 89/72860 DC ISBN 0 580 22578 X Committees responsible for this British
3、 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: Advanced Manufacturing Technology Research Institute Associated Offices Technic
4、al Committee Cold Rolled Sections Association Cranfield Institute of Technology Health and Safety Executive Independant Engineering Insurers Committee Machine Tool Technologies Association Metal Forming Machinery Makers Association Ministry of Defence Trades Union Congress Coopted members Amendments
5、 issued since publication Amd. No. Date CommentsBS 7708:1993 BSI 09-1999 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 Definitions 1 3 Characteristics and dimensions 2 Annex A (informative) Bibliography 4 Figure 1 Typical construction of a
6、high-speed press 2 Table 1 3BS 7708:1993 ii BSI 09-1999 National foreword This British Standard has been prepared under the direction of the Machine, Engineers and Hand Tools Standards Policy Committee. It is identical with ISO9189:1993 Machine tools Straight-sided high speed mechanical power presse
7、s from250kN up to and including 4000kN nominal force Characteristics and dimensions, prepared by Technical Committee ISO/TC39, Machine tools, and published by the International Organization for Standardization (ISO). ISO 9189 is based on recommendation number 7 published by the European Power Press
8、Manufacturers Panel (EPPMP) (Secretariat AMTRI, Macclesfield) which was established in1967 by power press manufacturers sponsored by the machine tool associations of the following countries: Belgium, Denmark, France, Federal Germany, Great Britain, Italy, Netherlands, Portugal, Spain, Sweden and Swi
9、tzerland. The Netherlands withdrew from the panel in January1971. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity
10、 from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 4 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the ins
11、ide front cover.BS 7708:1993 BSI 09-1999 1 Introduction Values are not specified in this International Standard for all the dimensional, geometric and operational characteristics of high-speed straight-sided mechanical power presses owing to the restrictions that this would place on the performance
12、and development of these presses. Those features which are not not covered by this International Standard are listed below, and the reason(s) for their exclusion are given. a) Hole in bed and bedplate, and bedplate thickness These directly influence the rigidity of the press and as such are often di
13、mensioned to suit the production of a specific component. One common practice, which is employed to maintain maximum bed stiffness, is to machine discharge holes only where they are required as dictated by the pitch of the press tooling. b) Height of bedplate from floor The use of automatic feeding
14、and unloading mechanisms makes the specification of floor-to-bedplate height undesirable. c) Tool fixing holes and T-slots Owing to the relatively high stroking speed of these presses, the designer always endeavours to minimize the mass of the reciprocating parts. It is usually impracticable to achi
15、eve total balance of these masses and as a result the press members will be subjected to high disturbing forces. By specifying the tool fixing holes, the die and press designer would be restricted in achieving the optimum solution for each application. d) Passage through uprights, and strip width Th
16、ese may be standardized at a later date if them is sufficient support for this work. e) Stroking rate Standardization would impede further technical progress since this characteristic depends on the specific application of the press (feed length, type of feed; gripper, roller, step motor; type of di
17、e, length of stroke, feed-out of parts, etc.). Modern high-speed presses can be provided with a variable adjustable stroking rate from1 to10. f) Energy The working energy cannot be fixed since the stroking rate is variable over a wide range. For example, for an adjustable range of stroking rate of1
18、to10 as mentioned in e), the working energy changes at a ratio of1 to100. g) Rated force travel Energy is only a result of the rated force and the rated force travel. Since the rated force has a constant value, but energy is dependent on the stroking rate, no fixed value can be given for the rated f
19、orce travel (the rated force travel can, for example, be increased by raising the stroking rate). h) Slide ejection distance, and die cushion force Ejectors are usually built into the tooling, and die cushions are rarely fitted to these presses. i) Strip feeders and scrap shears The specification of
20、 strip feeders and scrap shears is not given here, as it is available in documents on accessories. j) Geometric accuracy, and deflection under load Some high-speed presses are manufactured to very stringent geometric tolerances. To apply these tolerances to all high-speed presses would limit freedom
21、 in design and inhibit commercial competition. These properties may be standardized at a later date if them is sufficient support for this work characteristics. 1 Scope This International Standard specifies the characteristics and dimensions for straight-sided high-speed mechanical power presses fro
22、m250kN up to and including 4000kN nominal force. 2 Definitions For the purposes of this International Standard, the following definitions apply. 2.1 high-speed press automatic, continuous-running, fixed-stroke straight-sided press for the production of components from strip material fed into the pre
23、ss by a strip feed mechanism. These presses are not intended for single-stroke operation 2.2 nominal force, F n maximum allowable pressing force which may act, before the bottom of the stroke, as frequently as required without damaging the press 2.3 shut height, normal slide stroke, e n distance fro
24、m the bedplate surface to the slide surface measured with the normal slide stroke, stroke down and slide adjustment upBS 7708:1993 2 BSI 09-1999 2.4 adjustable feed height, h f the height measured from the top of the bedplate NOTE 1The following formula may be used as a guide for determining fixed f
25、eed heights: where h bis the bedplate-to-slide height at mid-stroke. 3 Characteristics and dimensions Straight-sided high-speed mechanical power presses may be provided with either cranks or eccentric drive mechanisms. Figure 1 shows a typical construction of a straight-sided high-speed mechanical p
26、ower press; this figure is a schematic representation only and is not intended to affect the manufacturers design. The characteristics and dimensions shall be selected fromTable 1; values given in parentheses are non-preferred. NOTE 2All the values appearing in the same column in Table 1 are directl
27、y related and values from different columns should not be used in combination, with the exception of x 0see footnotef to Table 1. h f h o 0,75h v 2 - = Figure 1 Typical construction of a high-speed pressBS 7708:1993 BSI 09-1999 3 Table 1 Nominal force F n a(see2.2) kN 250 400 630 (800) 1 000 (1 250)
28、 1 600 (2 000) 2 500 (3 150) 4 000 Normal slide stroke, H b mm 20 20 25 25 25 25 30 30 30 35 35 Maximum slide stroke, H max c mm 50 50 50 50 50 50 60 60 60 60 60 Slide adjustment h v d mm 50 60 60 60 60 60 60 80 80 100 100 Shut height, normal slide stroke, e n e(see2.3) mm 275 300 325 350 350 375 37
29、5 400 400 450 500 Badplate and slide width (left to right), x 0 f mm 630 710 800 900 1 000 1 200 1250 1 400 1 600 1 800 2 000 Badplate depth (front to back, y 0 g mm 530 560 600 630 670 710 800 900 1 000 1 120 1 250 Slide depth (front to back), y 1 h mm 425 450 475 500 530 560 630 710 800 900 1 000
30、Adjustable fead height, h f i(see2.4) mm 95 95 95 110 110 130 130 150 150 170 170 to to to to to to to to to to to 155 155 155 170 170 190 190 210 210 230 230 a The preferred values correspond to the R5 series of preferred numbers. b This is a fixed stroke and values are based on known and practical
31、 requirements. c Optional instead of the normal slide stroke and it is also fixed. d The values of h vare based on known and practical requirements. To permit easier access to the tools when in the press, it is recommended that the tools be designed with a shut height equal to e n 0,75 h v e The val
32、ues of e nare based on known and practical requirements. f Values in accordance with the R20 series of preferred numbers. When the standard width for a given press capacity is not suitable, then the next larger or smaller value may be selected fromTable 1. The suitability of the bedplate and slide w
33、idth will be dependent on the number of tool positions and the pitch of these tool positions. g Values in accordance with the R40 (530 . 710) and R20 (710 . 1 250) series of preferred numbers. It is not intended that this dimension be varied when the width x 0is non-standard. h Values in accordance
34、with the R40 (425 . 560) and R20 (560 . 1 000) series of preferred numbers. It is not intended that this dimension be varied when the width x 0is non-standard. i The values of h fare based on known and practical requirements.BS 7708:1993 4 BSI 09-1999 Annex A (informative) Bibliography 1 ISO 6898:19
35、84 Open front mechanical power presses Capacity ratings and dimensions. 2 ISO 8540:, Open front mechanical power presses Vocabulary 1) . 3 ISO 9188:1993, Machine tools Straight-sided single-action mechanical power presses from400kN up to and including 4000kN nominal force Characteristics and dimensi
36、ons. 1) To be published.5 blankBS 7708:1993 ISO 9189:1993 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is inco
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