Mathematical Simulation of Technological Equipment for Processing of Optical Parts
The paper describes a functional scheme of a machine-tool for simultaneous abrasive machining of lenses with shallow high-accuracy executive surface. The machine-tools permits flexibly and within long range to control shape-forma-tion process through changing such adjustment parameters as tool and rough workpiece frequency rotation, amplitude value of tool oscillatory motion, their diameters and number of double strokes per minute. While using the given machine-tool for machining process an operating force is directed along normal to the working surface and due to this there is a possibility to accelerate a shape-formation process of optical parts that leads to reduction of local errors on their executive surfaces. The paper considers a structure of the executive machine-tool mechanism which transfers translational motion to the tools and consists of rotational and rectilinear kinematic pairs forming a four-bar linkage and its crank is a guide link. A turning angle of the link is selected as a generalized coordinate of the executive mechanism. A relationship between the generalized coordinates and link positions of the executive machine-tool mechanism has been established in the paper and it permits to obtain analytical dependence between motions of input and output mechanism links with due account of its kinematic transfer function which represents in itself a ratio of angular output link speed to an angular velocity of the input link. An analysis of geometric parameters for backward-rotational motion of the top link in the proposed machine-tool has made it possible to obtain an expression to calculate a rod length of the executive mechanism which ensures symmetrical center position of the above-mentioned link relative to a symmetry axis of the bottom link. As an amplitude value of oscillatory motion for an output link in the executive mechanism is regulated in the machine-tool for two-sided lens machining while changing length of its input link (crank) an analytical relationship has been established between these geometric parameters and the relationship provides a possibility purposefully to change a machining intensity in the central or edge zone of a part according to technological blank heredity in the context of allowance which is to be removed and which is distributed along its surface.