1、UDC 331.101.1 : 331.102.342 : 62-514.4 DEUTSCHE NORM December 1986 Human physical strength Maximum static action moments applied by male operators when actuating hand-wheels - DIN 33411 Part 3 Krperkrfte des Menschen; maximal erreichbare statische Aktionsmomente mnnlicher Arbeitspersonen an Handrder
2、n In keeping with current practice in standards published by the International Organization for Standardization (KO), a comma has been used throughout as the decimal marker. 1 Scope and field of application This standard specifies criteria for selecting and aligning hand-wheels as a function of maxi
3、mum attainable static action moments. (An action moment here is understood to be either the breakaway or the closing moment.) It is intended to provide information on the maximum attainable breakaway and closing moments on the basis of the relationships and parameters for human physical strength giv
4、en in DIN 3341 1 Part 1. 2 Maximum attainable static action moments Table 1 givesvalues of the maximum static action moments which persons are able to apply to hand-wheels using both hands. The values are based on the following parameters. Operators were males accustomed to physical labour, and only
5、 bare hands were used. Both horizontal and vertical hand-wheel alignments were tested. The Ist, 5th, 50th and 95th percentiles were selected from a probability density function of action moments approaching normal distribution. The population consisted of 233 individuals and was di- vided into two s
6、ubpopulations. The first (225 individuals) was inhomogeneous as to age, physical attributes, and profession. This group was investigated at workplaces and actuated a hand-wheel that waseither vertical or hori- zontal. In the case of the other eight individuals, who formed a specially selected homoge
7、neous subpopulation, both types of hand-wheel alignment were tested under I a bo ratory conditions. The values given in table 1 are based on a select group of 132 physically fit male operators between the ages of 18 and 40, their height ranging from 1540 mm to 1950 mm, with an arithmetic mean of 175
8、3mm, and their weight from 47 kg to 1 13 kg, with an arithmetic mean of 77,7 kg. The boundary conditions were as follows. a) Actuation was manual (no gloves or other aids were used), two-handed, and both hands were at different positions on the rim (see figure 1). Force was exerted exclusively on th
9、e rim, irrespective of the direction of rotation. The operator stood on a clean,firm workshop floor and faced the hand-wheel, .e. the hand-wheels axis of rotation lay approximately in the plane of symmetry of the operators body. The operator was free to choose his posture and leg position. b) The op
10、erator actuated a stationary hand-wheel briefly (up to 4 s) with the maximum force he was able to exert. c) Two trials were made by each operator; the time inter- val between actuations was at least 30 s. d) Round, steel hand-wheels (as specified in DIN 950and DIN 951) were used, having a solid, rou
11、nd rim and spoke cross section and rounded junctions between spokes and rim. e) The hand-wheel surface was clean, dry, and had a tem- perature comfortable to the skin. The following influence factors were taken into account: a) the rim diameter, d, (from 160 mm to 400 mm); b) the hand-wheel alignmen
12、t (vertical or horizontal); c) the height, h, of the centre of the hand-wheel above the surface on which the operator stands (from 600 mm to 1800mm). Continued on pages 2 to 5 Beuth Verlag GmbH, Berlin. has the exclusive right of sale for German Standards (DIN-Normen) 07.89 DIN 3341 I Part 3 Engl. P
13、rice group 6 Sales No. O106 Page 2 DIN 33 41 1 Part 3 E E S .- .a Li c al al .- Q U E .- Li - a al r E ir C m I i Lo m Lo E 5 Lo 5 m I 4 m om00 aNNN Lom CoLoSjsj P444 goo0 cDCo88 mooo Loo mooo drfcid a 4 F DIN3341Part3 Page3 Note. As to the individual action forces and action mo- ments, DIN 33411 Pa
14、rt1 may be used as theguide- line for specifying the position of both points of application of force (see figure I), the direction of the line of action, the direction of force, and the magnitude of the actionforcesand action mo- ments applied to the hand-wheel rim. The above parameters have been al
15、lowed for in a simplified form by establishing the required action moment about the hand-wheel axis as an overall measure, which thus represents a whole body mo- ment. Similarly, the values given for the position of the centre of the hand-wheel represent the ab- m f= i Figure 1. Example of the relat
16、ive arrangement of the two points of application of force for a two- handed application of an action moment to a hand-wheel solute height, h, above the surface on which the operator stands. The direction of action moments corresponds to principal direction A for vertical and B for horizontal alignme
17、nt of the hand-wheel axis, the values applying to both positive and negative directions. 3 Instructions for use The actual boundary conditions for investigating the per- missible action moments on hand-wheels may differ from those described in this standard, such as the condition of the floor (which
18、 may be slippery) or the frequency of actuation. In rare cases of work being performed continu- ously on a hand-wheel, the values given in table 1 are too high. When specifying or evaluating action moments applied to hand-wheels, safety and cost factors shall be considered along with the ergonomic a
19、spects of the particular case (see Explanatory notes). The safety design of products is normally based on low percentiles (Ist or 5th). The specification of safety co- efficients which allow for the particular application, or other relevant parameters, may also need to be considered. When selecting
20、hand-wheel alignment, theeffects of body positions not covered here (e.g. kneeling) shall be con- sidered. Interpolation of the values given (e.9. the height of the centre of the hand-wheel, h) is permitted, due considera- tion being given to the influence factors. Corrections may be made to the val
21、ues given to allow for individual attributes different from those of the popula- tion investigated here (e.g. older or sedentary persons, women), or for combinations of such attributes. Theoretically, the permissible action moment can be derived from the smallest action moment to be expected from a
22、particular population. This approach, however, can only be applied in a small number of cases subject to particular safety requirements and, in practice, is ineffi- cient. One possible procedure to be followed in deter- mining the permissible action moment is described in the Explanatory notes. Page
23、 4 DIN 3341 1 Part 3 Standards referred to DIN 950 Hand-wheels, offset-arm type, with round hub hole DIN 951 Hand-wheels, offset-arm type, with square hub hole DIN 3341 1 Part 1 Human physical strength; concepts, relationships and parameters Other relevant documents Jenik, P.; Mainzer, J. Ergonomisc
24、he Bestimmung von Zulssigkeitsgrenzen (Ergonomic determination of marginsof permis- sibility), Zeitschrifr fr Arbeitswissenschaft, 1979: 33 (31, 178-185. Explanatory notes The percentile values given in table 1 are based on a nor- mal d&ribution_model with a coefficient of variation of 25%M, whereM
25、is equal to any valuefrom the 50th per- centile columns in table l. Specification of a permissible static action moment to be overcome when actuating a hand-wheel (M,) necessarily isolates the proportion (percentile) of individuals whoare not able to apply it. It is currently not possible to provide
26、 quantitative assess- ment and correction factors for permissible body forces which are generally valid for various loads and groups of operators. This is due in part to the composition of the group, the type of load, and numerous influence factors involved in the exertion of body forces. In fact, a
27、 permis- sible body force is only one of many parameters of per- missible load to be observed for one particular type of exertion. Another problem is that there are a number of ergonomic approaches which can be used to evaluate human labour on the basis of different hierarchically arranged systems.
28、In general, there lacks sufficient empirical evidence in this field, which affects all aspectsof theassessmentof human labour - its feasibility, tolerability, acceptability, and whether it is satisfying. Various margins of permissibility can be specified for all of these aspects. In practice, the pe
29、rmissible action moment,M, is to be established usinga known distribution of maximum attain- able static action moments as determined by a large num- ber of individuals. This can beeffected by considering the individual aspectsof thecase to be investigated,e.g. safety and physiological requirements,
30、 where such considerations are not necessarily subject to any particular set of rules. A number of correction factors isconceivable (e.g. safety conditions or factors differentiating groups of workers according to gender and age), which could give rise to a displacement of normally distributed actio
31、n moments or to an adjustment of the available data to suit the particu- lar application. The derivation of a permissible action moment is illus- trated in the three diagrams shown in figure 2. Diagram a shows the theoretical probabilitydensityfunction (normal distribution) of action moments,Mi, as
32、determined for a large population and diagram b illustiates the distribution function, which is the integral of the probability density function of these action moments. Theoretically, the probability density function applies to all values of the defined characteristic, .e. from - 00 to +m. In reali
33、ty, however, the values of attainable action moments usually only fall within a range limited by m andM (see diagram b). Given normal distribution, the action moment, derived graphically in the simplified distribution function (see diagram b), can be applied by approximately 90% and M by 10% of the
34、population. This assumesthat theslopeof the straight line passing through (m, O %) and (M,JOO%) is equal to the slope of the actual distribution at M. The values of m and M can be calculated for any percentile of the actual distribution function by using the values specified in table 1. Using a give
35、n distribution function, a collective total capacity,K, can be defined as a function ofthedistribu- tion, If, of the static action moments, Mi, established. It can also be more simply defined as the total area of the trapezium to the left of the connecting line between the minimum value, m, and maxi
36、mum value,M,of theaction moment. This definition is illustrated in diagram c. The collective total capacity is represented by theshaded area to the left of the line m - M. By selecting either a maxi- mum permissible action moment,M, or an appropriate value of the distribution function,H, the shaded
37、area can be divided into three subsections: Ka, Ku and Ki. The amount of utilized collective total capacity can now be defined as the ratio of Ki to K, .e. utilized capacity to collective total capacity. The utilized capacity can be manipulated (e.g. maximized) by selecting either the per- missible
38、action moment or the value of the distribution function. In other words,M, (or H,) can be selected so as to produce a maximum area Ki. A mathematical analysisof this shows thatM = I ,3M and m = 0,7M, assuming normal distribution of the action momentsMi and using 25%M as the coefficient of varia- tio
39、n. Thus, for the given example, optimum utilization of the collective total capacity may bedeemed to be achieved if approximately 90% of the population is able to apply the permissible action moment. DIN 33 41 1 Part 3 Page 5 c 100 .- a- $ 50 C 3 ro v: L .- 0 o s .f t - -/ c 0 I Y v) -. .- n / -. O
40、m M M Action moment, O .e 10 1 I 1 I ,/-. . Y v) I” O in Nm a) Theoretical probability density function of the action moments t b) Actual and simplified distribution function of action moments for one observed actuation T Key to figure 2c: K - collective total capacity =Ka +Ki + Ku, in Nm Ki - utili
41、zed component of the total capacity of opera- tors who were able to apply at least M, in Nm I- Maximum Ku- unused component of the total capacity of opera. tors who were able to apply at least M, in Nm Graphic representation of collective total capacity and its components Ka- component of the total capacity of operators who were not able to applyM, in Nm Figure 2. Derivation of the permissible action rnoment,M, International Patent Classification A 61 B 5/22
