《BS-6912-17-1995 ISO-7096-1994.pdf》由会员分享，可在线阅读，更多相关《BS-6912-17-1995 ISO-7096-1994.pdf（14页珍藏版）》请在三一文库上搜索。
1、BRITISH STANDARD BS 6912-17: 1995 ISO 7096:1994 Safety of earth-moving machinery Part 17: Specification for laboratory evaluation of operator seat vibration Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:42:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6912-17:1995 This British Standar
2、d, having been prepared under the direction of the Sector Board for Building and Civil Engineering, was published under the authority of the Standards Board and comes into effect on 15 August 1995 BSI 04-1999 The following BSI references relate to the work on this standard: Committee reference B/513
3、/1 Draft for comment 93/105240 DC ISBN 0 580 24290 0 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee B/513, Construction equipment and plant, and site safety, to Subcommittee B/513/1, Earth-moving machinery, upon which th
4、e following bodies were represented: British Coal Corporation Construction Plant-Hire Association Federation of Civil Engineering Contractors Federation of Manufacturers of Construction Equipment and Cranes Health and Safety Executive Institution of Civil Engineers Silsoe Research Institute Amendmen
5、ts issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:42:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6912-17:1995 BSI 04-1999i Contents Page Committees responsibleInside front cover National forewordii 1Scope1 2Normative references1 3Symbols
6、and indices1 4Criteria for evaluation of seats1 5Vibration testing of operator seats1 6Conditions for acceptance of seat3 7Test report3 Figure 1 Posture of test person6 Figure 2 Normalized power spectral density for classes I and II7 Figure 3 Illustration of tolerances for normalized power spectral
7、density of input vibration8 Table 1 Definition of spectral classes of input vibrations4 Table 2 Characteristics of simulated input vibration on z-axis for different types of machines4 Table 3 Report form for simulated input vibration testing of seats5 Table 4 Report form for damping test5 List of re
8、ferencesInside back cover Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:42:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6912-17:1995 ii BSI 04-1999 National foreword This Part of BS 6912 has been prepared by Subcommittee B/513/1, and is identical with ISO 7096:1994, Earth-moving mach
9、inery Laboratory evaluation of operator seat vibration, published by the International Organization for Standardization (ISO). This Part supersedes BS 6294:1982 Method for measurement of body vibration transmitted to the operator of earth-moving machinery, which is withdrawn. The second edition of I
10、SO 7096 represents a technical revision of ISO 7096:1982 and was prepared by Subcommittee 2, Safety requirements and human factors, of ISO Technical Comittee 127, Earth-moving machinery, with the active participation and approval of the UK. The Technical Committee has reviewed the provisions of ISO
11、8041 and of ISO 10326-1, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct
12、 application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-reference International standardCorresponding British Standard BS 6914 Terminology (including definitions of dimensions and symbols) for earth-moving machinery ISO 6165:1987Part 1:1988 G
13、lossary of terms for basic types of earth-moving machinery (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments i
14、ncorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:42:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 7096:1994(E) BSI 04-19991 1 Scope This International Standard specifies a laboratory method for vibrati
15、on testing of operator seats for earth-moving machinery at frequencies between 1 Hz and 20 Hz. It is based on ISO 10326-1 which is a general method applicable to seats for different types of vehicles: this International Standard lays down the specifications which relate particularly to earth-moving
16、machinery. It applies to operator seats of the following earth-moving machines as defined in ISO 6165: wheel-loaders and crawler-loaders; tractor-scrapers; wheel-tractors and crawler-tractors. 2 Normative references The following standards contain provisions which, through reference in this text, co
17、nstitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions
18、of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 6165:1987, Earth-moving machinery Basic types Vocabulary. ISO 8041:1990, Human response to vibration Measuring instrumentation. ISO 10326-1:1992, Mechanical vibration Laborator
19、y method for evaluating vehicle seat vibration Part 1: Basic requirements. 3 Symbols and indices For the purposes of this International Standard, the following symbols and indices apply. 3.1 Symbols 3.2 Indices 4 Criteria for evaluation of seats Two criteria are used for the evaluation of seats: the
20、 vibration magnitude measured between the seat pan and the test person (see ISO 10326-1:1992, subclause 9.1); transmissibility at resonance (see ISO 10326-1:1992, subclause 9.2). Users of this International Standard are reminded that the quantities referred to shall be calculated from the accelerati
21、on values measured simultaneously on the vibration table and between the seat pan and the test person or the inert mass. The specifications for instrumentation shall be as given in ISO 8041. Measurements during testing shall be made with type 1 instruments according to ISO 8041. The frequency filter
22、 shall have a 12 dB/octave slope at the relevant cut-off frequencies. 5 Vibration testing of operator seats 5.1 Seat mounting A platform, the dimensions of which correspond approximately to those of the operators position on an earth-moving machine, shall be mounted on a vibrator which is capable of
23、 generating vibrations along the (vertical) z-axis (see Figure 1). The vibrator shall, when loaded, be capable of simulating sinusoidal vibrations having a displacement amplitude equivalent to at least 7,5 cm, at a frequency of 2 Hz. 5.2 Seat adjustment The seat shall be adjusted to the mass of the
24、test person in accordance with the manufacturers instructions. With seats where the stroke available is unaffected by the adjustment for seat height or test person mass, testing shall be performed with the seat adjusted to the centre of the stroke. With seats where the stroke available is affected b
25、y the adjustment of the seat height or by test person mass, testing shall be performed in the position which gives the minimum available stroke. The manufacturer shall specify what influence different combinations of mass and seat height adjustments will have on the stroke available during testing.
26、aInstantaneous acceleration, in metres per second squared. awFrequency-weighted acceleration signal, in metres per second squared. fFrequency, in hertz. fcFilter cut-off frequency. frResonance frequency. Power spectral density. GoStandard spectral power, in square metres per second cubed (m/s2)2/Hz.
27、 j Assumed unit (j2= 1). T (fr)Resonance transmission factor. GP * f( )/Go P Platform S Seat Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:42:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 7096:1994(E) 2 BSI 04-1999 When the inclination of the backrest is adjustable, the angle shall b
28、e approximately 10 5 behind the vertical. 5.3 Test person and posture The simulated input vibration test shall be performed with two persons with masses of 55 kgkg and 98 kgkg. To meet the required mass of the test persons, added weights may be used, e.g. a belt weight of 5 kg for the light and 8 kg
29、 for the heavy person. Each person shall adopt a natural position on the seat and maintain this position throughout the test (see Figure 1). Differences in the posture of the test person can cause a 10 % difference between test results. Provision shall therefore be made for adjustment of angles of k
30、nees and ankles as specified in Figure 1. 5.4 Test procedure Suspension seats require a run-in period that is long enough for the seat performance to stabilize before testing. Carry out the run-in procedure specified in ISO 10326-1:1992, subclause 7.1.2. 5.4.1 Simulated input vibration test Three te
31、sts shall be performed for each subject in accordance with ISO 10326-1:1992, subclause 9.1. The effective duration of each test shall be at least 300 s. The results of measurements made on the seat awS and on the platform awP may be corrected, as indicated in ISO 10326-1:1992, subclause 9.1, last pa
32、ragraph, in order to bring them into line with the reference conditions for the input vibrations. This International Standard defines the input vibration in four spectral classes: I, II, III and IV. Each class is defined by a normalized power spectral density, and the weighted rms acceleration measu
33、red on the platform (see Table 1 and Table 2, and Figure 2). The seats for all machines except wheel-loaders are tested according to one spectral class. Wheel-loaders generally perform two specific tasks (load and carry corresponding to driving, and short cycle corresponding to loading). Therefore,
34、testing according to two spectral classes, II and III, shall be performed. See Table 2 and Table 3. 5.4.2 Damping test The seat shall be loaded with an inert mass of 75 kg and then be excited by a sinusoidal vibration in the range from 0,5 Hz to 3 Hz. The inert mass shall if necessary be secured to
35、the seat to prevent it from moving on the seat or falling off. The frequency range shall be investigated with either a constant frequency sweep from 0,5 Hz to 3 Hz and back again to 0,5 Hz or in steps of maximum 0,05 Hz. The frequency sweeping shall be made during at least 80 s. The damping test and
36、 the calculation of the transmissibility at resonance shall be performed according to ISO 10326-1:1992, subclause 9.2. The frequency weighted root-mean-square (rms) acceleration, awp(f) for a vertical input excitation corresponding to a constant displacement amplitude is defined as follows: for clas
37、ses I, II and III: for class IV and for longitudinal excitation: 5.5 Tolerances on input vibration The input excitations applied to the seat, as defined in 5.4, can be produced on a simulator only with a certain degree of approximation. The test shall satisfy the conditions in 5.5.1 to 5.5.3 in orde
38、r to be acceptable. 5.5.1 Distribution function Use should be made of procedures having a Gaussian cumulative probability density, truncated at 3,5 times the standard deviation. 0 3 +5 0 GP * f( )/Go a wP f ( )25 f2 2 - -= a wP f ( )15 0 6f2, 2 - -= Licensed Copy: sheffieldun sheffieldun, na, Wed De
39、c 06 12:42:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 7096:1994(E) BSI 04-19993 5.5.2 Normalized power spectral density The power spectral density of the acceleration measured on the platform is considered to be representative of if, and only if: These tolerances are illustrated in Figure 3.
40、The numerical values of f1 and f2 are: f1 = 1 Hz for classes I, II and III f1 = 3 Hz for class IV f2 = 4 Hz for classes I and II f2 = 16 Hz for class III f2 = 18 Hz class IV 5.5.3 rms value The rms value of the acceleration obtained in the course of all testing shall lie within a relative range of 1
41、0 % in relation to the reference value: NOTE 1For the damping test the platform vibration may be measured by a displacement pick-up. In this case the tolerance of 10 % applies to the displacement amplitude. 6 Conditions for acceptance of seat The conditions for acceptance of the seat are the followi
42、ng; the transmissibility T(fr) at resonance in the z-axis shall not exceed 1,5 for classes I and II, and 2 for classes III and IV; the magnitude of vibration in the z-axis transmitted to the heavy and to the light operator shall not exceed (in acceleration terms) 1,25 m/s2. 7 Test report The test re
43、port shall give the following information: a) name and address of the seat manufacturer; b) model of seat, product and serial number; c) date of test; d) time duration of run-in period, in hours; e) type of measuring disc used: semi-rigid, rigid; f) characteristics of the simulated input vibration t
44、est; g) vibration transmission to the persons at the simulated input vibration test: test persons mass in kilograms, Seat Effective Amplitude Transmissibility (SEAT-factor), corrected magnitude on the seat surface; h) transmissibility at the resonance during the damping test and the resonance freque
45、ncy, or alternatively the transfer function with sinusoidal vibration input; i) the name of the person responsible for the test; j) identification of test laboratory. GP * f ( ) Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:42:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 7096:1994(E
46、) 4 BSI 04-1999 Table 1 Definition of spectral classes of input vibrations Table 2 Characteristics of simulated input vibration on z-axis for different types of machines Spectral class of input vibration Filter cut-off frequency, fc LP6LP12HP12LP24HP24 I 1,275 5 (HP24)2 (LP24)2 2,5 Hz1,5 Hz II 1,128
47、 5 (HP24)2 (LP24)2 3 Hz1,5 Hz III 1,451 7 (HP24)2 (LP6)2 3,5 Hz1,5 Hz IV 2,314 (HP12)2 (LP12)2 9 Hz6,5 Hz Where NOTEHP and LP designate high-pass and low-pass filters of the Butterworth type. The subscripts state the filter slope in decibels per octave. This table defines band-pass filters completel
48、y in terms of cut-off frequencies and slopes. Type of machine Input vibration rms acceleration on platform Weighted rms acceleration on platform Frequency range to calculate ClassGo Frequency range Octave band (m/s2)2/Hzm/s2m/s2Hz Tractor-scraper non-spring- suspended I4,155 32,3521,715 from 0,708 H
49、z to 11,22 Hz 8 with spring suspension II2,410 22,0501,595 Wheel-tractor, wheel-loader load and carry II2,410 22,0501,595 Short cycleIII0,764 61,9761,678 form 0,708 Hz to 22,39 Hz 16 Wheel-tractorIII0,764 61,9761,678 Crawler-tractor, crawler-loader IV0,341 41,6921,397 GP * f( )/Go LP6 1 1S+ -= LP12 1 11 414,SS2+ - -= HP12 S2 11 414S,S2+ - -= LP24 1 12 613,S3 414 S2,2 613 S3,S4+ -