化工工艺流程图阀门程序设计
提要:本文针对化工工艺流程图CAD阀门绘制程序设计，探讨CAD在化工工艺设计中的运用。文后提供的程序清单可在AutoCAD R12中文环境下运行，对化工工艺设计CAD二次开发提供经验与技巧。
CAD技术已广泛应用于各专业设计，但在化工工艺设计领域内商品化软件不足，这就需要各设计单位自行开发应用软件以适应CAD技术的发展.本文提供的阀门绘制程序是在AutoCAD二次开发的化工工艺计算机辅助设计CPCAD系统中的一个独立程序，它以AutoLisp语言编写，功能全，使用方便，具有可读性及一定的技巧。
● 阀门绘制要求
在AutoCAD上绘制阀门，要求于已存在的工艺管道上据阀门类型自动按一定的比例显示，图纸输出时的尺寸符合专业制图要求，(原因是不可能根据阀门的实际尺寸与其它化工设备按同一比例绘图) 并自动切断管道线，同时判断管线与水平方向的夹角，可取代AutoCAD的copy。阀门型式全，层自动设置并不受原当前层的影响。
● 程序简介
该程序针对以上要求，提供11种常用阀型，可方便地进行选择.如需其它类型，可对源程序简单地修改补充。
1.主控程序
在主控程序中，(if (and (/= *bl nil) (/= *dwgscale nil))判断变量*bl及*dwgscal是否存在.如不存在程序不再执行，因此需在ACAD.LSP中加载或在command下赋值(注:*bl=*dwgscale)。如(setq *bl 100) (setq *dwgscale 100)，100为绘图比例。Progn语句段完成图层设置，下面的缺省值设计读者可自行分析，具有通用性和一定的技巧。
2.阀门程序的公用子程序
该部分是程序的核心.阀门长度的赋值是绘图比例的5倍，当以相同比例输出时其长度为5mm。法兰的绘制是可选择的。当提示阀心位置时，选择line实体，程序可就选择的line实体的起点和终点坐标计算该线与水平方向的夹角，同时求出各绘制点的极坐标。需要强调的是对Pline折线不适用，其原因是起点与终点的连线和要绘阀门不一致。(一般地，如需粗线可在出图时对绘图仪的参数进行设置)该子程序中又调用法兰设计子程序，这是AutoLisp允许的，而且是一很好的功能。
3.其它子程序相对简单，不再介绍。
●.附源程序清单VA
(defun *ERROR* (st)
(menucmd "s=s")
(command "osnap" "none")
(command "layer" "s" cl "")
(setvar "regenmode" 1)
(princ st)
(terpri)
)
(defun qs （）
(setq fc (* 5.0 *bl))
(menucmd "s=s")
(initget "Y N")
(if (not *yffl) (setq *yffl "N"))
(princ "\n有否法兰: [ Y/N ]﹤ ")
(princ *yffl)
(setq fl (getkword " ﹥"))
(if (not fl) (setq fl *yffl) (setq *yffl fl))
) (defun dfw ( )
(command "OSNAP" "NEAR")
(setq e1 (entsel "\n阀心位置:"))
(command "osnap" "none")
(defun gy（）
(setq zx (cadr e1)
e2 (entget (car e1))
p01 (cdr (assoc 10 e2))
p02 (cdr (assoc 11 e2))
zj (+ (* (/ 1.0 2.0) pi) (angle p01 p02))
l1 (/ fc 1.732)
l2 (/ l1 1.0)
p1 (polar zx (+ zj (* (/ 2.0 3.0) pi)) l2)
p2 (polar zx (+ zj (* (/ 1.0 3.0) pi)) l2)
p3 (polar zx (+ zj (* (/ 4.0 3.0) pi)) l2)
p4 (polar zx (+ zj (* (/ 5.0 3.0) pi)) l2)
p11 (polar zx (+ zj (* (/ 1.0 2.0) pi)) (* 0.867 l2))
p21 (polar zx (+ zj (* (/ 2.0 3.0) pi)) (* 0.48 l1))
p22 (polar zx (+ zj (* (/ 1.0 3.0) pi)) (* 0.48 l1))
p23 (polar zx (+ zj (* (/ 4.0 3.0) pi)) (* 0.48 l1))
p24 (polar zx (+ zj (* (/ 5.0 3.0) pi)) (* 0.48 l1)))；setq
(flsz)
(command "break" p32 p33 )
)
(defun qf ( )
(while e1
(gy)
(command "line" p21 p1 p2 p22 ""
"line" p23 p3 p4 p24 ""
"circle" zx (* 0.48 l1))；command
(dfw)
)；while
(PRINC)
)
(defun jz ( )
(while e1
(gy)
(command "line" p1 p2 p3 p4 p1 "")
(dfw)
(PRINC)
)
)
(defun zf ( )
(while e1
(gy)
(setq l3 (/ l2 2)
p7 (polar zx (+ zj (* (/ 1.0 1.0) pi)) l3)
p8 (polar zx (+ zj (* (/ 0.0 1.0) pi)) l3))；setq
(command "line" p1 p2 p3 p4 p1 ""
"line" p7 p8 "" )；command
(dfw)
(PRINC))；while
)
(defun dx ( )
(while e1
(gy)
(command "line" p1 p2 p3 p4 p1 ""
"solid" zx p3 p4 "" "")；command
(xzjd)
(command "rotate" "c" p2 p3 "" zx zj)
(dfw)
)
(PRINC)
)
(defun xzjd（）
(initget "Y N")
(if (not *xz) (setq *xz "N"))
(princ "\n镜像旋转: [ Y/N ]﹤ ")
(princ *xz)
(setq xz (getkword " ﹥"))
(if (not xz) (setq xz *xz) (setq *xz xz))
(if (= xz "N") (setq zj 0.0) (setq zj 180.0))
) (defun xs ( )
(while e1
(gy)
(command "line" p1 p2 p3 p4 p1 ""
"donut" 0 (* 0.8 l1) zx "")；command
(dfw)
)；while
(PRINC)
)
(defun jl ( )
(while e1
(gy)
(command "line" p1 p2 p3 p4 p1 ""
"solid" zx p3 p4 "" ""
"solid" zx p1 p2 "" "")；command
(dfw)
)；while
(PRINC)
)
(defun jy ( )
(while e1
(gy)
(command "line" p1 p3 p4 p2 p1 ""
"line" p3 p11 p4 "")；command
(xzjd)
(command "rotate" "c" p2 p3 "" zx zj)
(dfw)
)；while
(PRINC)
)
(defun gm ( )
(while e1
(gy)
(setq p44 (polar zx (+ zj (* 0.0 pi)) (* 0.6 l1)))
(command "line" p1 p2 p3 p4 p1 ""
"arc" p24 p44 p22)；command
(dfw)
)；while
(PRINC)
) (defun df ( )
(while e1
(gy)
(command "line" p1 p3 p4 p2 p1 ""
"circle" zx (* 0.5 l1))；command
(dfw)
)；while
(PRINC)
)
(defun ss ( )
(while e1
(gy)
(setq p55 (polar zx (* 0.25 pi) (* 0.45 fc))
p56 (polar zx (* 1.25 pi) (* 0.45 fc))
p57 (polar zx (* 1.25 pi) (* 0.225 fc)))；setq
(command "pline" p57 "w" (* 0.45 fc) "" "a" "ce" zx "a" 180 ""
"line" p55 p56 ""
"circle" zx (* 0.45 fc) )；command
(dfw)
)；while
(PRINC)
)
(defun kz ( )
(while e1
(gy)
(setq k1 (polar zx zj (* l2 0.7))
kzx (polar zx zj (* l2 0.35))
k2 (polar k1 (+ zj (* (/ 1.0 2.0) pi)) (/ l2 2.0))
k3 (polar k1 (+ zj (* (/ 3.0 2.0) pi)) (/ l2 2.0))
k4 (polar k1 zj (/ l2 2.0)))；setq
(command "line" p1 p2 p3 p4 p1 ""
"line" k2 k3 ""
"line" k1 zx ""
"arc" k2 k4 k3)；command
(xzjd)
(command "rotate" "c" kzx k4 "" zx zj)
(dfw)
)；while
(PRINC)
)
(defun flsz（）
(if (= fl "Y")
(progn
(setq p32 (polar zx (+ zj (* (/ -1.0 2.0) pi)) (* 3.0 *bl))
p33 (polar zx (+ zj (* (/ 1.0 2.0) pi)) (* 3.0 *bl))
pf1 (polar p32 (+ zj (* 0.0 pi)) (* 0.5 l1))
pf2 (polar p32 (+ zj (* 1.0 pi)) (* 0.5 l1))
pf3 (polar p33 (+ zj (* 1.0 pi)) (* 0.5 l1))
pf4 (polar p33 (+ zj (* 0.0 pi)) (* 0.5 l1)))；setq
(command "break" p32 p33 "line" pf1 pf2 ""
"line" pf3 pf4 "")；command
)；progn
(setq p32 (polar zx (+ zj (* (/ -1.0 2.0) pi)) l2)
p33 (polar zx (+ zj (* (/ 1.0 2.0) pi)) l2))；setq
)；if
(princ)
)
(defun va( )
(if (and (/= *bl nil) (/= *dwgscale nil))
(progn
(setvar "cmdecho" 0)
(setvar "regenmode" 0)
(setq cl (getvar "clayer"))
(command "blipmode" "off"
"fill" "on"
"layer" "m" "va" "s" "va"
"lt" "continuous" "" "c" "green" "" "")；command
(initget "Q Z J D X L Y G W S K")
(if (not *fm) (setq *fm "J"))
(princ "\n球Q/闸Z/截J/单D/旋X/节L/减Y/隔G/蝶W/疏S/控K ﹤ ")
(princ *fm)
(setq fm (getkword " ﹥:"))
(if (not fm) (setq fm *fm) (setq *fm fm))
(cond ((= fm "Q") (qs) (dfw) (qf))
((= fm "Z") (qs) (dfw) (zf))
((= fm "J") (qs) (dfw) (jz))
((= fm "D") (qs) (dfw) (dx))
((= fm "X") (qs) (dfw) (xs))
((= fm "L") (qs) (dfw) (jl))
((= fm "Y") (qs) (dfw) (jy))
((= fm "G") (qs) (dfw) (gm))
((= fm "W") (qs) (dfw) (df))
((= fm "S") (qs) (dfw) (ss))
((= fm "K") (qs) (dfw) (kz)))；cond
(command "layer" "s" cl "")
(setvar "regenmode" 1)
(princ)
)
)
)；end
(va)
princ)
)
)
)；end
(va)
