【正文】 am with a translating conical follower is found by applying the procedure described below. Usually, with the considerations of dimensional accuracy and surface finish, the most convenient way to machine a cylindrical cam is to use a cutter whose size is identical to that of the conical roller. In the process of machining, the cylindrical blank is held on a rotary table of a 4axis milling machine. As the table rotates, the cutter, simulating the given followermotion program, moves parallel to the axis of the cylindrical blank. Thus the cutter moves along the ruled surface generated by the follower axis, and the cam surface is then machined along the contact lines step by step. If we have no cutter of the same shape, an available cutter of a smaller size could also be sued to generate the cam surface. Under the circumstances, the cutter path must be found for a general endmill cutter. Figure 3 shows a tapered endmill cutter machining a curved surface. The front portion of the tool is in the form of a cone. The smallest radius is R, and the semicone angle is β. If the cutter moves along a curve δ =δ0 on the surface X=X（ δ， ф2）， the angle σ between the unit vector of the cutter axis ax and the unit mon normal vector n at contact point C is determined by cos xna? ?? (14) Thus the path of the point ? on the cutter axis that the vector n passes through is ? ?? ?39。英文資料翻譯 英文原文： Design and machining of cylindrical cams with translating conical followers By DerMin Tsay and Hsien Min Wei A simple approach to the profile determination and machining of cylindrical cams with translating conical followers is presented .On the basis of the theory of envelopes for a 1parameter family of surfaces,a cam profile with a translating conical follower can be easily designed once the followermotion program has been given .In the investigation of geometric characteristics ,it enables the contact line and the pressure angle to be analysed using the obtained analytical profile expressions .In the process of machining ,the required cutter path is provided for a tapered endmill cutter ,whose size may be identical to or smaller than that of the conical follower .A numerical example is given to illustrate the application of the procedure . Keywords : cylindrical cams, envelopes , CAD/CAM A cylindrical cam is a 3D cam which drives its follower in a groove cut on the periphery of a cylinder .The follower, which is either cylindrical or conical, may translate or oscillate. The cam rotates about its longitudinal axis, and transmits a transmits a translation or oscillation displacement to the follower at the same time. Mechanisms of this type have long been used in many devices, such as elevators, knitting machines, packing machines, and indexing rotary tables. In deriving the profile of a 3Dcam, various methods have used. Dhande et and Chakraborty and dhande2 developed a method to find the profiles of planar and spatial cams. The method used is based on the concept that the mon normal vector and the relative velocity vector are orthogonal to each other at the point of contact between the cam and the follower surfaces. Borisov3 proposed an approach to the problem of designing cylindricalcam mechanisms by a puter algorithm. By this method, the contour of a cylindrical cam can be considered as a developed linear surface, and therefore the design problem reduces to one of finding the centre and side profiles of the cam track on a development of the effective cylinder. Instantaneous screwmotion theory4 has been applied to the design of cam mechanisms. GonzalezPalacios et used the theory to generate surfaces of planar, spherical, and spatial indexing cam mechanisms in a unified framework. GonzalezPalacios and Angeles5 again used the theory to determine the surface geometry of spherical camoscillating rollerfollower mechanisms. Considering machining for cylindrical cams by cylindrical cutters whose sizes are identical to those of the followers, Papaioannou and Kiritsis6 proposed a procedure for selecting the cutter step by solving a constrained optimization problem. The research presented in this paper shows q new, easy procedure for determining the cylindricalcam profile equations and providing the cutter path required in the machining process. This is acplished by the sue of the theory of envelopes for a 1parameter family of surfaces described in parametric form7 to define the cam profiles. Hanson and Churchill8 introduced the theory of envelopes for a 1parameter family of plane curves in implicit form to determine the equations of platecam profiles Chan and Pisano9 extended the envelope theory for the geometry of plate cams to irregularsurface follower systems. They derived an analytical description of cam profiles for general camfollower systems, and gave an example to demonstrate the method in numerical form. Using the theory of envelopes for a 2parameter family of surfaces in implicit form, Tsay and Hwang10 obtained the profile equations of camoids. According to the method, the profile of a cam is regarded as an envelope for the family of the follower shapes in different camfollower positions when th