ISO 5393:2017 ねじ付きファスナー用の回転工具—性能試験方法 | ページ 6

3.1

angle

measure of the angular displacement through which a fastener is turned

Note 1 to entry: Expressed in degrees (°).

3.2

built-in torque measurement system

torque measurement system incorporated within a power assembly tool for tightening threaded fasteners with which the torque delivered at the output drive is measured within the tool for display, storage or control purposes

3.3

combined mean torque

midpoint of the combined torque scatter (3.5) of a tool between the lowest and highest predictable torque readings, encompassing 99,73 % or more of all possible readings

3.4

combined precision of the indicated torque

predicted range of deviation of the value indicated by the built-in torque measurement system (3.2)

Note 1 to entry: From the value indicated by the in-line measuring instrument.

Note 2 to entry: Encompassing 99,73 % or more of all possible torque deviations of indicated torque, taken on a range of joints of varying torque rate, from a defined high torque rate through and beyond a defined low torque rate.

Note 3 to entry: Characterized both by the mean shift of indication and the scatter of the torque difference.

3.5

combined torque scatter

ΔT_comb

predictable range of torque values delivered by a tool on a range of joints having a specified high torque rate (3.23) and a specified low torque rate at the same setting of the tool torque adjustment

Note 1 to entry: The indicated values encompassing 99,73 % or more of all possible torque readings.

Note 2 to entry: For practical purposes, combined torque scatter of a tool is the total probable range of torque of a tool run on all joints used in practice at the same setting of the tool torque adjustment.

3.6

combined torque scatter as a percentage of the combined mean torque

single numerical value designating the predictable range of torque values as delivered by a tool on a range of joints, having a specified high torque rate (3.23) and a specified low torque rate at the same setting of the tool torque adjustment

3.7

indicated torque

T_Ind

torque indicated by the power tool’s built-in torque measurement system (3.2)

3.8

mean shift

difference in mean torque (3.9) of a tool run on threaded joints of two different torque rates (3.23) at the same setting of the tool torque adjustment

3.9

mean torque

arithmetic average of several torque readings on a specific joint under stated conditions, calculated by dividing the sum of the readings by the number of readings

3.10

non-shut-off tool

power assembly tool for tightening threaded fasteners, which delivers an output torque as long as power is applied to the motor

Note 1 to entry: A stall tool is an example of a non-shut-off tool.

3.11

rated torque

highest mean torque (3.9) , as defined by the manufacturer, attainable by a tool tested on a low torque-rate joint (L)

Note 1 to entry: In accordance with 5.2.4.

3.12

run-down

period of angular rotation without corresponding torque increase

Note 1 to entry: This allows the tool to reach operating speed.

3.13

automatic shut-off tool

power assembly tool for tightening threaded fasteners, which is provided with a torque control mechanism which shuts off or disconnects the power to the tool when predetermined set output torque level is attained

3.14

standard deviation

s

measure of the scatter based on the mean-squared deviation from the arithmetic mean derived from a sample of a statistical population

3.15

6s

range of probability, plus and minus three standard deviations (3.14) from the mean, derived from a sample of a statistical population

Note 1 to entry: For a normally distributed statistical population, 99,73 % of all members of that population are encompassed.

3.16

6s torque scatter

predictable range of torque over which a tool performs using a single torque-rate joint under controlled conditions

Note 1 to entry: For the practical purposes of this document, 6s torque scatter is the total probable range of torque of a tool run on a single joint at the same setting of the tool torque adjustment.

3.17

6s torque scatter as a percentage of the mean torque

single numerical value designating the predictable range of torque over which a tool performs on a single torque-rate joint under controlled conditions

3.18

test torque level

mean torque (3.9) level to which a test tool is adjusted on a low torque-rate joint (L)

Note 1 to entry: In accordance with 5.2.4.

3.19

tightening time

time required for the tool to complete the tightening process, beginning at 10 % of the test torque level (3.18) and ending at the peak dynamic torque

3.20

torque

T

product of the force turning the fastener and the perpendicular distance between the line of force and the centre of the fastener

Note 1 to entry: Expressed in newton metre (N·m).

Note 2 to entry: For the purposes of this document, peak measured torque during a tightening cycle, measured with the in-line measuring instrument as specified in 5.2.3.

3.21

torque adjustment range

range over which a power tool can be adjusted from the rated torque to the lowest mean torque (3.9) recommended by the manufacturer

3.22

torque difference

D

difference between the torque indicated by the power tool’s built-in torque measurement system (3.2) and the in-line torque measurement system

Note 1 to entry: The calculation of torque difference is specified in Annex E.

Note 2 to entry: The in-line torque measurement system is specified in 5.2.3.

3.23

torque rate

increase in torque with angular displacement while advancing a fastener in a threaded joint

Note 1 to entry: Expressed in newton metre per revolution (N·m/r).