Удосконалення конструкції системи базування поздовжньо-фрезувальних верстатів

Abstract

Based on the analysis of the designs of peripheral-milling machines, it was found that, according to the principle of operation, all the machines have a movable locating system, which is the dominant factor influencing the accuracy of machining and introduces an error of up to 60% of the total error of machining on these types of machine. As a result of theoretical studies on the influence of the structures of the locating systems, it was found that on a jointing machine, the greatest error is caused by the height of the rear plate placement, while on a thicknessing machine - the presence of rollers in the table plate. To improve the accuracy of machining on peripheral-milling machines, it is proposed to replace the movable locating system with the positional locating of workpieces on the feeding carriage. The design of a four-side peripheral-milling machine S20PK has been developed based on the principle of operation of a cyclo-through type with positional locating of blanks on a feeding carriage, which ensures the accuracy of machining a profiled bar measuring 4,000 x 200 x 200 mm within ±0.07–0.34, as well as the possibility of machine operation with the participation of one operator. As a result of experimental studies, a regression model of the dependence of machining accuracy on the S20PK machine on the feed rate and the thickness of the removed layer was obtained, which makes it possible to set rational milling modes to ensure machining accuracy in accordance with the requirements of current standards (± 0.1 mm).