CC BY
37
Актуальные проблемы авиации и космонавтики - 2015. Том 2
UDK 621.791
ELECTRON BEAM WELDING AND BEAM POSITIONING
M. (Y.) Morozov Scientific supervisor - V. (Y.) Braverman Foreign language supervisor - D. (M.) Mednikov
Reshetnev Siberian State Aerospace University 31, Krasnoyarsky Rabochy Av., Krasnoyarsk, 660037, Russian Federation
Programs for control of mutual movements of the welded parts and EB gun are written in the unified language ISO-7bit. Beam settings control uses electronic charts or optional languages, sometimes self-designed. Operator coordinates movements and beam settings manually.
Keywords: electron beam welding, positioning, CCD matrix, CCD-technology.
ПОЗИЦИОНИРОВАНИЕ ЛУЧА ПРИ ЭЛЕКТРОННО-ЛУЧЕВОЙ СВАРКЕ
М. Ю. Морозов Научный руководитель - В. Ю. Браверман Руководитель по иностранному языку - Д. М. Медников
Сибирский государственный аэрокосмический университет имени академика М. Ф. Решетнева
Российская Федерация, 660037, г. Красноярск, просп. им. газ. «Красноярский рабочий», 31
Для управления взаимным перемещением свариваемых деталей и ЭЛС, как правило используются программы, написанные на едином стандартизованном языке ISO - 7bit, а для управления электронным лучом - электронные таблицы либо программы на нестандартном языке программирования, как правило собственной разработки.
Ключевые слова: электронно-лучевая сварка, позиционирование, ПЗС матрица, ПЗС-техно-
логия.
Electron beam welding unit (EBW) is an automated complex, which comprises high-performance vacuum and energy equipment. High rate of welding process and poor visibility appear to be a problem even for an experienced operator. Thus, it is necessary to achieve maximum automation of the process. Nowadays, automated EBW can be obtained through the complex automation with the help of computer engineering [1].
Secondly, emissive and video systems for EBW control designed in the period from 60-s to 80-s do not meet the requirements for modern technologic equipment. Most of these control systems are designed based on bi-computer scheme. One of the computers controls mutual movements of welded parts and electron-beam gun (EB gun), and the second one controls the beam settings. Programs for control of mutual movements of the welded parts and EB gun are written in the unified language ISO-7bit. Beam settings control uses electronic charts or optional languages, sometimes self-designed. Operator coordinates movements and beam settings manually. That is an old-fashioned state of business. Its main shortcomings are absence of the uniform concept of the control systems' creation for this type of processing equipment and necessity in cooperation of experts in EBW and automation of process equipment [3].
The core element of positioning system is the sensor of beam position in relation to the welding joint. The choice of the sensor determines precision positioning and quality of welding joint. It can be profitable to use positioning sensor based on Charge Coupled Device matrix (CCD), which detects the X-ray band emission. CCD matrix is a special analog integrated silicon based circuit, made of optical diodes, and using CCD-technology (Charge Coupled Device) [3].
Possibilities of a CCD regarding registration of images are limited to noises, which mainly are noises of scanning. Time for charge transmission from pixel to pixel is characterized by clock frequency, the maximum value of which determines acceptable time for charge transmission from pixel to pixel. CCD matrix is an inertia-free device, so it fits perfectly for highly-reliable digital technologies, alongside with registration
Секция «Актуальные на учные проблемы в мире (глазами молодых исследователей)»
of X-ray emission in EBW processes. Moreover, X-ray beam size is known to depend on the precise positioning of the beam with welding joint, and beam current [4].
CCD matrix is produced and used by Nikon, Canon, Kodak, Matsushita, Philips, etc. Russian manufacturers of CCD matrix are OJSC NRI "ELECTRON" and its branch Closed Joint-Stock Company "Research and Production Enterprise "ELAR" St. Petersburg.
Figure displays operating scheme of CCD matrix. EBW starts in vacuum chamber with generating X-ray emission. That emission (signal) is detected at the input of CCD, analog signal from the output goes to a filter and an amplifier, and then it is converted by analog-to-digital coder into digital signal (digitized). Micro controller transmits decoded signal to servo-amplifier, then to the servo-drive in the vacuum chamber, which performs gun or item positioning. At the same time beam current can be adjusted via control channel by signal from micro controller, thus modifying welding depth.
Operating diagram of CCD matrix control system.
References
1. Murigin A. V. (2006) Electron Beam Welding Management Using Information Properties of the Density Distribution of the Electron List available at: http://www.dslib.net/avtomatizacia-upravlenia/upravlenie-processom-jelektronno-luchevoj-svarki-s-ispolzovaniem-informacionnyh.html, 20 March. [20 March 2015].
2. Zalesski V. (2008) CNC Systems Extended Functions for EBW Unit Control. List available at: http://www.cniim.com/files/technology_svarka_2008.pdf, 20 March. [20 March 2015].
3. Wikipedia | CCD Matrix | List available at: http://ru.wikipedia.org/wiki/%CF%C7%D1-%EC%E0%F2%F0%E8%F6%E0, 2014. 20 March. [20 March 2015].
4. Braverman V. Y., Veisver T. G., Braverman V. Y., Belozertsev V. S. [Welding Depth Control by Means of X-ray Emission Intensity]. Vestnik SibGAU. 2010, Iss. 6(32), pp. 116--119. (In Russ.)/
© Morozov M. (Y.), 2015
