凸轮连杆机构课程设计..

第一章固定凸轮连杆机构参数选取1.确定驱动方案图1如上图所示，设：与从动杆升程运动相对应的曲柄转角为1，即101ABB;而与降程运动相对应的曲柄转角为，即3323ABB,则：（1）当21＞时，选用曲柄AB拉着BC杆运动的方案。（2）当21＜时，选用曲柄AB推着BC杆运动的方案。（3）当21时，任选其中一种驱动方案。已知数据1101，1503，很明显21＜，所以选用方案2。2.确定e直动从动杆，取mSe2.0~0，取0e3.确定h从结构紧凑和减小凸轮压力角考虑，应将h值取小些。但h值愈小，对从动杆驱动力的压力角也愈大。通常取mSh，去mmh1204.确定a若a值过小，会使凸轮压力角明显增大，甚至不能实现预期动动。可取a=0.6~0.9Sm或a=1.2~1.8lsin2m。取a=70mm6、确定其值对凸轮的压力角影响极大，过小，尤其是过大，会使压力角急剧增加。在前述参数确定后，最好将优化，目标函数为a1m()（a1m）min式中a1m为凸轮的最大压力角。暂时取87.求算b1、b2须先求算bmax、bmin。依据铰销B、D的坐标，可建立它们之间距离的公式。B的坐标为)cos()sin(ayaXBBD的坐标为ShyeXDD式中——曲柄转角，取升程起始时的=0°；S——与相对应的从动杆位移，即铰销D至其最低位置的距离。S值分为升程（=0～1）、最高位置停留（=1～1+2）、降程（=1+2～1+2+3）、最低位置停留（=1+2+3～360°）四个阶段求算。b值为b=22)()(DBDByyxx（1）用matlab编程画出b与曲线图，并算出minmaxbb、：clearsm=100;h=120;e=0;a=70;d=8*pi/180;fa1=110*pi/180;fa2=0*pi/180;fa3=150*pi/180;fa4=100*pi/180;fa01=0:0.001:fa1;s=sm/2*(1-cos(pi*fa01/fa1));xb=a*sin(d+fa01);yb=-a*cos(d+fa01);xd=e;yd=h+s;b=sqrt((xb-xd).^2+(yb-yd).^2);plot(fa01,b);max(b)min(b)holdon;fa02=fa1;s=sm;xb=a*sin(d+fa02);yb=-a*cos(d+fa02);xd=e;yd=h+s;b=sqrt((xb-xd).^2+(yb-yd).^2);plot(fa02,b,'r--d');max(b)min(b)holdon;fa03=fa1+fa2:0.001:fa1+fa2+fa3;s=sm*(1-(fa03-fa1-fa2)/fa3+1/(2*pi)*sin(2*pi*(fa03-fa1-fa2)/fa3));xb=a*sin(d+fa03);yb=-a*cos(d+fa03);xd=e;yd=h+s;b=sqrt((xb-xd).^2+(yb-yd).^2);plot(fa03,b,'g-');max(b)min(b)holdon;fa04=fa1+fa2+fa3:0.001:fa1+fa2+fa3+fa4;s=0;xb=a*sin(d+fa04);yb=-a*cos(d+fa04);xd=e;yd=h+s;b=sqrt((xb-xd).^2+(yb-yd).^2);plot(fa04,b,'r-');max(b)min(b)xlabel('fa');ylabel('b');title('fa-b');运行结果：ans=217.0095ans=189.3564b=197.0794b=197.0794ans=197.0794ans=94.1923ans=190.0000ans=136.7980由以上结果可以看出1923.940095.217minmaxbb并且b取最大值时，fa=1.2~1.4；b取最小值时，fa=3.5~3.7（2）根据minmaxbb、计算21bb、)(212)(211minmaxminmaxbbbbbb1923.940095.217minmaxbb解得：b1=61.4086b2=155.60098、设计凸轮廊线固定凸轮的理论廊线就是滚子中心C的运动轨迹线，根据铰销B、D的位置及b1、b2值可确定C的位置。参阅1，令铰销B、D的连线BD与DOD1线（或y轴）的夹角为θ，BD与CD的夹角为β，则BDDBDByyxxarctgbXxarcsin2212222arccosbbbbb显然，XB＞XD时θ为正值，反之则为负值，而β始终为正值。这样，铰销C的坐标为)cos()sin(22byybxxDcDc该式对直动和摆动两种从动杆类型都适用，运算符号“+”和“—”的确定原则是：令B=bmax时的为m，b=b时的为′m，则对于AB推动BC的驱动方案（如图4所示），在=m～′m区间，取“—”号；在=0～m和=′m～360°区间，取“+”对于AB拉动BC的驱动方案，则刚好相反。（1）用matlab求famax、faminclearsm=100;h=120;e=0;a=70;d=8*pi/180;fa1=110*pi/180;fa2=0*pi/180;fa3=150*pi/180;fa4=100*pi/180;fa01=1.2:0.01:1.4;s=sm/2*(1-cos(pi*fa01/fa1));xb=a*sin(d+fa01);yb=-a*cos(d+fa01);xd=e;yd=h+s;b1=sqrt((xb-xd).^2+(yb-yd).^2);f=polyval(b1,fa01);fa03=3.5:0.01:3.7;s=sm*(1-(fa03-fa1-fa2)/fa3+1/(2*pi)*sin(2*pi*(fa03-fa1-fa2)/fa3));xb=a*sin(d+fa03);yb=-a*cos(d+fa03);xd=e;yd=h+s;b3=sqrt((xb-xd).^2+(yb-yd).^2);f=polyval(b3,fa03);运行结果：b1b1=Columns1through13216.1970216.3140216.4223216.5220216.6128216.6945216.7672216.8306216.8846216.9291216.9639216.9890217.0042Columns14through21217.0095217.0046216.9896216.9642216.9284216.8821216.8252216.7575fa01fa01=Columns1through131.20001.21001.22001.23001.24001.25001.26001.27001.28001.29001.30001.31001.3200Columns14through211.33001.34001.35001.36001.37001.38001.39001.4000b3b3=Columns1through1394.611694.507694.418594.344394.284894.240194.210194.194694.193694.207094.234794.276694.3325Columns14through2194.402394.485994.583294.694094.818294.955595.106095.2693fa03fa03=Columns1through133.50003.51003.52003.53003.54003.55003.56003.57003.58003.59003.60003.61003.6200Columns14through213.63003.64003.65003.66003.67003.68003.69003.7000由以上数据可以看出：famax=1.33famin=3.58(2)凸轮的设计clearsm=100;h=120;e=0;a=70;d=8*pi/180;fa1=110*pi/180;fa2=0*pi/180;fa3=150*pi/180;fa4=100*pi/180;famax=1.33;famin=3.58;b1=61.4086;b2=155.6009;fa01=0:0.002:famax;s=sm/2*(1-cos(pi*fa01/fa1));xb=a*sin(d+fa01);yb=-a*cos(d+fa01);xd=e;yd=h+s;b=sqrt((xb-xd).^2+(yb-yd).^2);theta1=asin((xb-xd)./b);beta1=acos((b.^2+b2.^2-b1.^2)./(2*b*b2));xc=xd+b2*sin(theta1+beta1);yc=yd-b2*cos(theta1+beta1);plot(xc,yc);holdon;fa02=famax:0.002:fa1;s=sm/2*(1-cos(pi*fa02/fa1));xb=a*sin(d+fa02);yb=-a*cos(d+fa02);xd=e;yd=h+s;b=sqrt((xb-xd).^2+(yb-yd).^2);theta1=asin((xb-xd)./b);beta1=acos((b.^2+b2.^2-b1.^2)./(2*b*b2));xc=xd+b2*sin(theta1-beta1);yc=yd-b2*cos(theta1-beta1);plot(xc,yc,'r');holdon;fa03=fa1+fa2:0.002:famin;s=sm*(1-(fa03-fa1-fa2)/fa3+1/(2*pi)*sin(2*pi*(fa03-fa1-fa2)/fa3));xb=a*sin(d+fa03);yb=-a*cos(d+fa03);xd=e;yd=h+s;b=sqrt((xb-xd).^2+(yb-yd).^2);theta1=asin((xb-xd)./b);beta1=acos((b.^2+b2.^2-b1.^2)./(2*b*b2));xc=xd+b2*sin(theta1-beta1);yc=yd-b2*cos(theta1-beta1);plot(xc,yc);holdon;fa04=famin:0.002:fa1+fa2+fa3;s=sm*(1-(fa04-fa1-fa2)/fa3+1/(2*pi)*sin(2*pi*(fa04-fa1-fa2)/fa3));xb=a*sin(d+fa04);yb=-a*cos(d+fa04);xd=e;yd=h+s;b=sqrt((xb-xd).^2+(yb-yd).^2);theta1=asin((xb-xd)./b);beta1=acos((b.^2+b2.^2-b1.^2)./(2*b*b2));xc=xd+b2*sin(theta1+beta1);yc=yd-b2*cos(theta1+beta1);plot(xc,yc,'r');holdon;fa05=fa1+fa2+fa3:0.002:fa1+fa2+fa3+fa4;s=0;xb=a*sin(d+fa05);yb=-a*cos(d+fa05);xd=e;yd=h+s;b=sqrt((xb-xd).^2+(yb-yd).^2);theta1=asin((xb-xd)./b);beta1=acos((b.^2+b2.^2-b1.^2)./(2*b*b2));xc=xd+b2*sin(theta1+beta1);yc=yd-b2*cos(theta1+beta1);plot(xc,yc);title('凸轮轮廓曲线');9.检验压力角（1）凸轮的压力角1参阅图1，1为PC和Vc的夹