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发表于 2015-2-10 19:40:28
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本帖最后由 seekfor 于 2015-2-10 19:41 编辑 & t+ |$ G" w% x4 c
% x8 k3 O# E* N3 R O$ d2 U其实人家图纸根本没有错,你想歪了。
) {% R( y! d; ?3 W9 M1、从这个视图看过去那根线就是表示的那个表面,注意(默认的basic dimension 90°)。并没有你所表述的、歪成那样的位置下(basic dimension 不为90°)再评价垂直度。我觉得你把这个垂直度理解为平面度了。
4 h \1 b, A) W. }9 b附上一些尺寸的基本原则:
/ B- C: f7 G9 @3 H% _0 ca) Each dimension shall have a tolerance, except for those dimensions specifically identified as
+ u' B& {- M( g! W7 l% R4 preference, maximum, minimum, or stock (commercial stock size). The tolerance may be applied directly
& r5 a$ l1 E( z" B& j! {5 ^6 [) Ato the dimension (or indirectly in the case of basic dimensions), indicated by a general note, or located in" C* r0 A% f; l' o2 g- o
a supplementary block of the drawing format. See ANSI Y14.1.
) M3 B, C: H; n7 B8 E7 Q( q5 i(b) Dimensioning and tolerancing shall be complete so there is full understanding of the characteristics of each feature. Neither scaling (measuring the size of a feature directly from an engineering' N" T3 e5 t+ U0 Y% d7 l7 j* n$ {
drawing) nor assumption of a distance or size is permitted, except as follows: Undimensioned drawings,! _0 k, m/ D5 {
such as loft, printed wiring, templates, and master layouts prepared on stable material, are excluded2 _1 G+ [4 c9 z
provided the necessary control dimensions are specified.
' F, V2 }+ s) Y. i" }(c) Each necessary dimension of an end product shall be shown. No more dimensions than those
. ` L/ \% k8 z" tnecessary for complete definition shall be given. The use of reference dimensions on a drawing should
7 k3 ^0 s7 M. c p' D/ mbe minimized.. Q; C$ I$ j! \2 C6 R/ n4 k
(d) Dimensions shall be selected and arranged to suit the function and mating relationship of a part
# {7 [/ }$ {: i* nand shall not be subject to more than one interpretation.
8 } a) `1 ^) l2 o(e) The drawing should define a part without specifying manufacturing methods. Thus, only the
% V* I, V4 O, hdiameter of a hole is given without indicating whether it is to be drilled, reamed, punched, or made by any
$ w0 W& y9 v, c3 _ g: c$ u! Rother operation. However, in those instances where manufacturing, processing, quality assurance, or1 ]% K% Q) @( ?. s( H
environmental information is essential to the definition of engineering requirements, it shall be specified on the drawing or in a document referenced on the drawing.
: m; d4 H5 `" |8 a& D(f) It is permissible to identify as nonmandatory certain processing dimensions that provide for
5 u8 D: y4 l0 P% e9 l3 ufinish allowance, shrink allowance, and other requirements, provided the final dimensions are given on7 h) C2 I( h! D9 l8 a; d: n/ [
the drawing. Nonmandatory processing dimensions shall be identified by an appropriate note, such as
1 y" s8 X7 j' K7 @ w+ ONONMANDATORY (MFG DATA).
) R X2 Q" {( L( @$ n(g) Dimensions should be arranged to provide required information for optimum readability. Dimensions should be shown in true profile views and refer to visible outlines.
. z5 U& |2 q$ b# {. C(h) Wires, cables, sheets, rods, and other materials manufactured to gage or code numbers shall be
- h) i4 X8 d. k3 Sspecified by linear dimensions indicating the diameter or thickness. Gage or code numbers may be
. v- S. V- J T% N7 ~shown in parentheses following the dimension.0 S" B5 @$ C+ J3 Y# l9 i
(i) A 90° angle applies where center lines and lines depicting features are shown on a drawing at" b! ]8 R6 e7 i! y1 f0 |0 [
right angles and no angle is specified.
! _3 L( C4 ^- d+ B+ P, _. D(j) A 90° basic angle applies where center lines of features in a pattern or surfaces shown at right7 d3 T, b7 @+ I' R* x7 q$ z% U9 a0 ?
angles on the drawing are located or defined by basic dimensions and no angle is specified.
! y) @$ Y9 r! ~; T/ m(k) Unless otherwise specified, all dimensions are applicable at 20°C (68°F). Compensation may be# M3 |' Q! x6 u1 D/ `3 L; S$ [
made for measurements made at other temperatures.0 X5 Q1 x+ x$ q: d/ y
(l) All dimensions and tolerances apply in a free state condition. This principle does not apply to
+ Y7 O& Q4 W3 |$ Q& h' j7 o% v, Inonrigid parts as defined in section 5.5.; R4 d' b Z& P! r
(m) Unless otherwise specified, all geometric tolerances apply for full depth, length, and width of the3 S6 f; f7 O: i6 y% ~
feature.
% x9 p9 G" M! X# G8 x1 K(n) Dimensions and tolerances apply only at the drawing level where they are specified. A dimension m* ?- e6 u! W2 S' U& i
specified for a given feature on one level of drawing, (for example, a detail drawing) is not mandatory for
, p0 L" j% c+ }' p Hthat feature at any other level (for example, an assembly drawing) h6 H' o) F; G7 m
一下是其中一个中文PPT中的,中文的仅供参考,翻译不全感觉,也感觉不是很贴切愿意。
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