Design of the Globoidal Cam Mechanism Based on MATLAB and CATIA

Working profile of Globoidal indexing cam is a complex surface. 2D mechanical drawing is difficult to describe it clearly. With the development of computer technology, the 3D design software such as CATIA, Pro-E, Solidworks, UG/NX, the solid and surface function of them make productions more excellent. Globoidal indexing cam profile equations firstly was studied, the geometric size of the globoidal indexing cam mechanism was calculate, and then use MATLAB to calculate the globoidal indexing cam contour surface 3D coordinates of points, finally completed the three-dimensional modeling of globoidal indexing cam in CATIA.

Applied Mechanics and Materials Vols 716-717 (2015) pp 720-723 © (2015) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMM.716-717.720 Submitted: 2014-11-11 Accepted: 2014-11-13 Online: 2014-12-31 Design of the Globoidal Cam Mechanism Based on MATLAB and CATIA Chao Zhang1, a ,Zhihong Zhang1,a Jiangsu Changzhou Higher Vocational Technical School of Construction, Changzhou, 213000, China a a zhangchaohyit@163.com, 2218067131@163.com Keywords: Globoidal Cam Mechanism; MATLAB; CATIA Abstract Working profile of Globoidal indexing cam is a complex surface 2D mechanical drawing is difficult to describe it clearly With the development of computer technology, the 3D design software such as CATIA, Pro-E, Solidworks, UG/NX, the solid and surface function of them make productions more excellent Globoidal indexing cam profile equations firstly was studied, the geometric size of the globoidal indexing cam mechanism was calculate, and then use MATLAB to calculate the globoidal indexing cam contour surface 3D coordinates of points, finally completed the three-dimensional modeling of globoidal indexing cam in CATIA Introduction Globoidal indexing cam mechanism is a kind of mechanical equipment, suitable for high speed space in the intermittent motion mechanism Because of non-developable surface of globoidal cam working profile, so the design is more difficult, but with the development of computer technology, the design speed of the globoidal cam can be faster with 3D design software as well as cost, improve the quality of design[1] In this paper the motion parameters of the globoidal indexing cam mechanism and geometry size are calculated, base of cam is created in CATIA, 3D coordinates of the work profile of globoid indexing cam are calculated in MATLAB, then the data points are imported into CATIA, three coordinate will be transformed to the CATIA point cloud Finally, finish the 3D model of globoidal indexing cam Contour Surface Equation of Globoidal Indexing Cam Mechanism Profile surface of globoidal indexing cam is not developable surface, and conventional design methods could not be used for this So we use the spatial envelope surface conjugate principle to carry on the design calculation Based on the analysis of spatial meshing principle, the establishment of globoidal indexing cam contour surface equation through coordinate transformation method is[2]: (l + h ) cos θ1 cos θ − r sin θ1 cos θ cos β − d cos θ − r sin θ sin β  R = (l + h ) sin θ1 + r cos θ1 cos β (l + h ) cos θ sin θ − r sin θ sin θ cos β − d sin θ + r cos θ sin β 2 2  The meshing equation of globoidal cam mechanism is: l +h tan β = ± [d − (l + h ) cos θ1 ]i Calculation of Globoidal Indexing Cam Mechanism Determination of working parameters Suppose the cam speed is n=300r/min, sinistrogyration, driven disc has stations, the center to center distance C=180mm, medium load, thus design the globoidal indexing cam mechanism All rights reserved No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, www.ttp.net (ID: 130.194.20.173, Monash University Library, Clayton, Australia-04/05/15,19:16:00) Applied Mechanics and Materials Vols 716-717 721 Compute the motion parameters of the globoidal indexing cam mechanism Cam angle 2πn 2π × 300 ω1 = = = 10π 60 60 velocity: ; the general value of cam phase angle is 2π ~ 4π , so the θ = 2π θ = 2π − θ f = 4π , so stop period angle is d ; rotary indexing number design value is: f I = obtained by the certain conditions is: , chose single head, then the turntable roller number is: z = HI = 1× = ; Rotary indexing phase transposition angle is: φ f = 2π I = π ; the motion law of turntable indexing period: the modified sine acceleration motion; motion stand ratio t t 1 15 τ= f = k= f = = t f + td t d 15 , the kinetic coefficient is: is: Three dimensional modeling of globoidal indexing cam The base model of globoidal indexing cam Use the sketch in the XY plane draw 2D drawing of the base, according to the value0 calculated, shown in Fig.1 left Use the command of rotation to rotate the sketch drawing around the center of the cam, drill a hole of 50mm, and get the 3D model shown in Fig.1 right Fig Basesketch (left) cam base(right) Globoidal indexing cam MATLAB calculation There are mainly kinds of different 3D modeling methods for globoidal indexing cam, such as: programming method, trajectory simulation method, two times the development, the functions of parametric curve of CAD software In this paper, we use MATLAB programming to calculate indexing cam working surface coordinates Fig Results of MATLAB 722 Mechanical Engineering and Materials Science Final treatment by CATIA Open the GSDPointSplineLoftFromExcel.xls from the CATIA installation directory, put the points from MATLAB between StartCurve and EndCurve, in which a group of StartCurve and EndCurve can generate a spline, different spline groups can generate a loft surface Shown in Fig.3 Fig Three dimensional cam profile coordinates Run the macro program, select the CreationPoint to generate the CATIA point cloud, as shown in Fig.4 is the 1L segment points of globoidal indexing cam and the surface generated Fig Point cloud (left) and surface (right) Repeat the above steps to make the 2L, 2R, 3R and the rest period of the surface, suture these surfaces as a whole, use command of closed surface to transfer surface to entity, 3D model eventually generated as shown in Fig.5 Fig Three dimensional model of globoidal indexing cam profile Three dimensional model of globoidal indexing cam Treat the part of globoidal indexing cam base as the target file, copy globoidal indexing cam contour into the base part, using Boolean operation to combine two geometries into one, cut off the excess part, three-dimensional model of globoidal indexing cam as shown in Fig Applied Mechanics and Materials Vols 716-717 723 Fig Three dimensional model of globoidal indexing cam Summary In this paper, based on the CATIA platform, the research of globoidal indexing cam mechanism is carried on With the help of MATLAB software, globoidal indexing cam profile could be calculated, there are many areas need to be improved, including: 1) Complete the research of CAD/CAM/CAE integration of the globoidal indexing cam mechanism by secondary development of the CATIA 2) Study the dynamics characteristics of the globoidal indexing cam mechanism, and error control in the future References [1] H Xi-Lin and L Tao: Globoidal Indexing Cam Mechanism Parameters Optimization Design and Simulation (Lanzhou University of Technology, 2012) [2] Y Dong-Xiang and H Zi-Hua: Research on the Integration of Globoidal Cam Mechanism CAD/CAM/CNC (Xiangtan University, 2007) [3] G Qing-Shan and Dan Bin-Bin: 3D Modeling and the NC Machining Simulation of the Roller Gear Indexing Cam Mechanism (Wuhan University of Technology, 2009) [4] Z Wang-Quan and G Wen-Jie: Study on Parametic Simulation and dynastic charachertic of Globoidal Cam Mechanism (Nortechhestern polytechnical university,2004) Mechanical Engineering and Materials Science 10.4028/www.scientific.net/AMM.716-717 Design of the Globoidal Cam Mechanism Based on MATLAB and CATIA 10.4028/www.scientific.net/AMM.716-717.720 ... dimensional model of globoidal indexing cam Summary In this paper, based on the CATIA platform, the research of globoidal indexing cam mechanism is carried on With the help of MATLAB software, globoidal. .. dimensional model of globoidal indexing cam profile Three dimensional model of globoidal indexing cam Treat the part of globoidal indexing cam base as the target file, copy globoidal indexing cam contour... development of the CATIA 2) Study the dynamics characteristics of the globoidal indexing cam mechanism, and error control in the future References [1] H Xi-Lin and L Tao: Globoidal Indexing Cam Mechanism