Device for automatic marking of billets for large diameter pipe bends

Abstract

The paper is devoted to description of the device for efficiency rise on conduction of marking operation during manufacture of large-size pipe bends. The existing method of marking applying and possibility of use of universal accessories, which displayed their low efficiency, were analyzed. The existing method of "lofting" is characterized by high labour intensity and low accuracy. Preliminary calculations of fabrication of universal accessories showed that it will be very expensive. The existing problem of low marking accuracy and high labour intensity of this process was solved owing to use of automation equipment. The device for measuring and marking, which is changeable accessories for industrial manipulating robot, was developed and described for this purpose. Architecture of the measuring and marking device and its elementary base, which allows to carry out automatic measuring of pipe bend billet, to conduct the required mathematical calculations and to apply marking, was described. The developed technique for measuring of pipe bend billet, allowing to determine the coordinates of basic points in the coordinate system of manipulating robot, was also described. Automation of transfer of the developed measuring and marking device was implemented via use of the industrial manipulating robot of Kuka Robotics company. Laboratorial example of this device was manufactured using the developed digital model. The experimental data that were presented in this paper displayed that accuracy of the laboratorial device corresponds to accuracy of marking applying via the existing technology and preliminary decrease of labour intensity was achieved about 50 %. The revealed disadvantages of construction of the laboratorial example of device were also described. Finally, the measures for improvement of accuracy of revealing the basic marking points were suggested; they include increase of a number of laser ranging devices and consequent calculation of coordinates on the base of average values of measuring data.