ISO 841:2001 pdf download

ISO 841:2001 pdf download.Industrial automation systems and integration—Numerical control of machines – Coordinate system and motion nomenclature.
Letter designations shall be used to denote movement of either the tool or the workpiece.
5.2.2 Moving the tool
When moving the tool, the direction of movement and the axes directions are equal. Positive movements are
designated with + X, + Y, + Z, + A, + B,…
5.2.3 Moving the workpiece
When moving the workpiece, the direction of movement and the axis direction are opposite. To indicate the opposite direction, positive movements are designated with + x’, + Y’, + Z’, + A’, + B’ … (i.e. the axis direction
— X = + X’ of the workpiece movement).
6 Additional motions
6.1 Linear motions
When, in addition to the primary linear motions X, Y and Z, there exists secondary linear motions parallel to the primary motions, these shall be designated U, V and W respectively. Similarly, for tertiary motions, they shall be designated P, Q and R respectively. When linear motions exist which are not (or may not be) parallel to X, Y and Z, they may be designated U, V, 14’, P, Q, or R as is most convenient.
The primary linear motions should be those nearest the principal spindle, the secondary the next nearest, and the tertiary are the farthest.
For milling machines, the cutting-bit with respect to a facing slide should be designated U or P if these letters are available.
For machines with multiple units or many parallel movements, the designation of these motions may be indexed by using a letter and a number (e.g. xl, X2, …). The index shall be a positive integer greater than zero. The primary motion(s) may or may not have an index. Thus it is possible on one machine to have motions with and without indices.
6.2 Rotary motion
When, in addition to the primary rotary motions, there exists secondary rotary motions, either parallel to A, B, or C or compounded or gimballed to A, B, or C, they shall be designated D or E (if these letters are available). As with linear motions, rotary motions may be indexed (see 6.1).
6.3 Letter restrictions
Certain letters (e.g. G, M, F) shall not be used for motion (see ISO 6983-1).
6.4 Direction
The rules given in 5.2 for determining the direction of principal machine motions shall apply to additional motions.
7 Schematic drawings of machines
7.1 Examples of machine drawings
The schematic drawings of machines in annex A are the official interpretation for those machines. Where a conflict exists between the text of this International Standard and a given schematic, the schematic drawing shall take precedence.
4.3 Zaxis
4.3.1 General
The z axis is parallel to the principal spindle of the machine. For the case where the machine has no spindle, see 4.3.4 and 4.3.5.
NOTE 1 On machines used for milling, grinding, boring, drilling and tapping, the spindle rotates the tool.
NOTE 2 On machines such as lathes, cylindrical gnnders and others which generate a surface of revolution, the spindle
rotates the work piece.
4.3.2 More than one spindle
Where there are several spindles, one shall be selected as the principal spindle, preferably perpendicular to the workholding surface.
4.3.3 Swivelling or gimballing spindle
Where the principal spindle can be swivelled or gimballed, the Z axis shall be parallel to spindle axis when the spindle is in the zero position. The preferred zero position is with the spindle perpendicular to the work-holding surface.
Where the principal spindle axis can be swivelled and if the extent of its motion allows it to lie in only one position parallel to one of the axes of the standard three-axis system, this standard axis is the Z axis.
Where the extent of the swivelling motion is such that the principal spindle can lie parallel to two of the three axes of the standard three-axis system, the Z axis is the standard axis which is perpendicular to the work holding surface of the work table of the machine, ignoring such auxiliary devices as mounting brackets or angle plates.
4.3.4 No spindle
For cutting and forming machines, the Z axis shall be perpendicular to the work-holding surface.
For coordinate measuring machines, the Z axis should be collinear with the acceleration of gravity vector (i.e.
perpendicular to the surface of the earth).
4.3.5 Direction
For cutting and forming machines, the + Z axis direction is defined from the workpiece to the tool holder.
NOTE For lathes, the tail stock is considered as the tool holder.
For coordinate measuring machines, the + Z direction is defined as in the opposite sense as the acceleration of
gravity vector (i.e. pointing away from the surface of the earth).
4.4 Xaxis
4.4.1 General
Where possible, the X axis shall be horizontal.