Value of the 3D Product Model Use in Assembly Processes: Process Planning, Design and Shop Floor Execution

Organizations can enhance the value of their assembly planning, assembly design, and assembly shop floor execution through the use of the 3D product model. Once a tool targeted at product design, the 3D product model, enabled by current and emerging manufacturing process management technologies, can create additional value for organizations when used in assembly processes. The research survey conducted and described in this paper demonstrates the value organizations have seen in using the 3D product model in the assembly process. The paper also explores the current state of those organizations who have not yet implemented the use of the 3D product model in their assembly processes and the value that they foresee for possible future implementation. The essential findings of this research are the five qualitative areas in which value is derived from using the 3D product model in complex assembly processes and how those value drivers apply across various industries and organization sizes. These results provide a framework for future research to develop quantitative models of the value of the 3D product model use in assembly processes.

Assembly Variation Analysis of Incompletely Positioned Macpherson Suspension Systems Considering Vehicle Load Change

The assembly precision of wheel alignment parameters is vital to vehicle handling stability. Due to the vertical wheel displacement and compliant components in suspension systems, it is difficult to assemble qualified vehicles with proper wheel alignment parameters. In the assembly shop of the automobile factory, the adjustment of wheel alignment parameters is the most time-consuming process because it relies on trial and error. In order to provide a theoretical guidance to the precision control of wheel alignment parameters, this paper extends the theory of equilibrium equations of incremental forces (EEIF) to 3D compliant mechanisms. Constraint equations of kinematic joints are adopted to express the spatial relationships of different parts. A couple of fixed and floating joint coordinate systems (CSs) are used together to represent deviations of compliant components. The impacts of suspension part deviations on vertical wheel displacement and assembly deformations are well illustrated by such approach. Accuracy of the proposed method is verified by comparing with ADAMS simulation. The results show that the error rates of the 3D EEIF method are less than 5%. Furthermore, statistical assembly variation analysis of a Macpherson suspension is accomplished by using the proposed method and an optimized process strategy is put forward.

IN-PLANT WELDING PRODUCTION ATMOSPHERE: ULYANOVSK AUTOMOBILE PLANT CASE-STUDY

Working conditions are among the most important factors affecting public health. Poor working conditions lead to high occupational morbidity. A third of the total number of employees are subject to an array of potentially harmful conditions at work. The purpose of the study is to assess the air pollution of the welders' working area in a modern engineering industry. Materials and Methods. The study involved 150 employees, including 100 welders (manual and semi-automatic welding were studied equally), as well as 50 people from the control group (25 locksmiths in the car assembly and delivery workshop and 25 engineers and technicians). The authors estimated time-weighted average concentrations. A total of 1900 air samples were analyzed. A PU-4E aspirator, a UG-2 gas analyzer, and a set of reagents were used for that purpose. Results. In-plant welding production atmosphere of the automobile manufacturer UAZ can be characterized as polluted and moderately polluted. In 47 % of samples, heavy metal content exceeded maximum allowable concentrations (MACs) by 1.5–3.0 times, in some cases by 5 times (in 6 % of samples). As you move away from the emission source, the concentration of harmful substances decreases sharply in all directions and it does not differ from the background air pollution indicators at a distance of 4 m. According to medical statistics, the overall incidence in the enterprise units is increasing as following: engineers and technicians < assembly shop workers < welding shop workers (welders). Conclusion. The highest concentrations and the largest number of samples exceeding MAC were recorded in shops with a manual method of metal welding. It results from multicomponent nature of the raw material and the lesser degree of gas contamination during semi-automatic welding. Keywords: welding, in-plant atmosphere, maximum allowable concentration (MAC), occupational diseases. Среди факторов, влияющих на здоровье населения, важную роль играют условия труда. Неудовлетворительные условия труда приводят к высокому уровню профессиональной заболеваемости. Треть от общего числа работников производства задействованы во вредных условиях. Цель исследования – оценка загрязненности воздуха рабочей зоны сварщиков в современном производстве машиностроения. Материалы и методы. В исследовании приняли участие 150 сотрудников, в т.ч. 100 сварщиков (в равных долях исследовалась ручная и полуавтоматическая сварка), а также 50 чел. из группы контроля (25 слесарей цеха сборки и сдачи автомобилей и 25 чел. из числа инженерно-технических работников (ИТР)). Оценивалась ПДК загрязняющих веществ среднесменная. Всего сделано 1900 анализов воздушной среды, которые были выполнены по общепринятым методикам с помощью аспиратора ПУ-4Э, газоанализатора УГ-2 и набора реактивов. Результаты. Воздух рабочей зоны сварочного производства предприятия машиностроения ООО «УАЗ» можно охарактеризовать как загрязненный и умеренно загрязненный. В 47 % проб наблюдается превышение ПДК тяжелых металлов в 1,5–3,0 раза, в отдельных случаях – в 5 раз (в 6 % проб). По мере удаления от источника выделения концентрация вредных веществ во всех направлениях резко уменьшается и на расстоянии до 4 м не отличается от фоновых показателей загрязнения воздуха помещения. По данным медицинской статистики, общая заболеваемость в подразделениях предприятия увеличивается в ряду: инженерно-технические работники < рабочие сборочного цеха < рабочие сварочного цеха (сварщики). Заключение. Наиболее высокие концентрации и наибольшее количество проб с превышением ПДК зафиксированы при ручном способе сварки металла, что обусловлено многокомпонентностью сырья и меньшей степенью загазованности при полуавтоматической сварке. Ключевые слова: сварка, воздух рабочей зоны, ПДК, профессиональные заболевания.

Studies of Application of LED-Based Lighting Devices in a Car Assembly Shop

The article describes the problem of replacement of active fluorescent lamp lighting installations of an assembly line of a car assembly plant with LED LDs including a comparison of the gained lighting and economic indicators. Therefore, several LED-based LDs by different manufacturers were selected. Based on LI computer modelling using DIALux Evo, an optimal option in terms of light engineering and economy was found. Lighting characteristics of the active LI and areas of the assembly line with the application of LED-based LDs were determined experimentally. The results of the study allow assessing relevant changing of visual performance of shop workers and to compare the pay-off periods of LED and fluorescent lamps-based lighting devices.