OBRABOTKAMETALLOV MATERIAL SCIENCE Том 23 № 3 2021 EQUIPMEN . INSTRUM TS Vol. 6 No. 4 2024 When organizing multi-tool setups, it is not uncommon when, several tools are mounted on one carriage, individual tools are rotated relative to other tools due to the use of special holders. For example, two turning cutters are placed, rotated relative to each other by 180°. To describe such a situation, the orientation vector of the cutting tool eu is introduced in formula (1). Here, the vector eu characterizes the direction of the axis of the cutting tool. By analogy with the vectors of the feed direction es and the location of the carriage ec, in this case it is also possible to introduce special designations for common typical situations (Table 5). Ta b l e 5 Special type designations for the orientation vector of the cutting tool No Orientation of the cutting tool Assignment of the vector eu 1 Along the x-axis x 2 Along the y-axis y 3 Along the z-axis z 4 In the xy plane, perpendicular to the z axis nz 5 In the xz plane, perpendicular to the y axis ny 6 In the yz plane, perpendicular to the x axis nx 7 In any direction in xyz space eu 8 Direction of the main component of cutting force from the cutting tool Descending +; Downward – Since the rotation of the cutting tool relative to the carriage is rarely used, it is proposed to describe the orientation of the tool only in cases where this rotation takes place. If the orientation of the tool coincides with the orientation of the working surfaces of the carriage, the element of the classifi cation formula (1), which describes the orientation of the tool, is omitted. The main goal of developing models of machining accuracy in multi-tool setups is to create eff ective algorithms for controlling the design process of these setups, assigning cutting conditions that ensure the required accuracy of all specifi ed dimensions. The structure of control algorithms is largely determined by the type and number of control parameters. Since the spindle speed during multi-tool setup is the same for all setup tools, cutting speed is not a direct control factor. It can only be taken into account for each tool. The direct control factor is the tool feed, of course, taking into account the simultaneous operation of all setup tools. On machines of the turning group, the feed is set for the carriage as a whole. Therefore, the number of carriages used in the setup already predetermines the number of given feeds, i.e. number of control factors. As a result, it is advisable to distinguish three main classes of multi-tool setups: single-carriage, doublecarriage and multi-carriage. As follows from the classifi cation formula (1), on machines of the turning group, especially modern CNC machines, feeds are divided into single-coordinate and two-coordinate feeds according to the method of implementation. Single-coordinate feed is when the feed direction coincides with one of the coordinate axes of the workpiece being machined. A two-coordinate feed is formed by adding two feeds, each of which is carried out along its own coordinate. In this case, unlike the fi rst one, we have two control factors (two coordinate feeds). The main classes of the proposed systematics of multi-tool setups are considered bellow. Results and Discussion To create a matrix theory of multi-tool machining accuracy, a set of multi-tool setups was organized and classifi ed. As a result, a formalized six-level classifi cation is developed, which includes the following
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