Engine Assembly Research Articles

Design Improvement of Assembly Workplace through Ergonomic Simulation and Analysis Using DELMIA

The aim of this research is to demonstrate the ergonomic process modeling and simulation of manual assembly work through virtual assembly approach in order to present workplace and process improvement prior to their physical prototyping. In this regard, a case study has been carried out to analyze an assembly workplace of a diesel engine by ergonomics simulation and virtual assembly approach. DELMIA, a software tool, has been exploited for the ergonomic simulation and analysis in virtual assembly environment. The case study demonstrates several improvements in the ergonomics of the operators performing assembly on production line of the diesel engine. The assembly process of last few stations of the diesel engine simulated and analyzed on DELMIA in order to exhibit the advantages of the virtual assembly approach to the workplace deign and saving of process time and energy expenditure of operator. On last station of the engine assembly line, parts are assembled relatively at higher and complex positions and it is difficult for an operator to assembly them. Since, the assembly is carried out on conveyor; it is not convenient to change the height of conveyor to overcome the problem. Therefore, height of the floor of last work station is altered / increased. In order to achieve the increased floor height, a number of benches of variable heights are placed on the floor on the last working station one by one in the simulation environment and simulation of the process is carried out. The simulation results show that the ergonomics of operators have significantly changed by altering working height of the operator. Simulation of second last and other working station has also been performed by altering the height of the floor, but no improvements in the ergonomics of the operator observed for these stations

Automation in Spillcut Marking

The project involves elimination of rejection of H-engines during testing by improved methods of automation in spill cut using pneumatics which control the injection timing and is subsequently used at a later state in the engine assembly to set the valve timing. Improper injection timing leads to excess smoke. The new method which we have opted reduces man power, time consumption and the fuel wastage an optimum level which increases the productivity of the engine.

Assembly process control method for remanufactured parts with variable quality grades

How to maximize the use of remanufactured parts with variable quality grade and improve the precision of reassembly (remanufacturing assembly) is the key to reassembly quality control. Firstly, based on analyzing the characteristics of reassembly for complex mechanical product, an assembly process control method of remanufactured product with different quality grade is proposed. Optimization model of reassemble scheme was constructed, which can describe the transmission process and the status of assembly precision in each assembly station, and characterize the relationship between assembly precision and remanufactured parts with various quality grades. Then, the solution is given by genetic algorithm, which can respond to abnormal quality situation during reassembly process and realize optimal control for reassembly process. Finally, a quality control of a prototype system for the remanufactured engine assembly is developed, which shows the feasibility and validity of the proposed method.

OPTIMIZATION OF TENSILE AND FLEXURAL MODULUS OF SILICA GEL REINFORCED ALUMINIUM MMC BY USING TAGUCHI METHOD

In the last two decades, the requirement of manufacturing industries for light weight machines and machine parts are growing. Aluminium Metal Composites (AMCs) have unique feature high strength to weight ratio. It’s hardness and mechanical properties make it versatile in various type of application like in engine assembly, aeronautics and other types of engineering application. In an aviation industry, aluminium composite having advantage of light weight and high mechanical properties like hardness, tensile strength, flexural strength etc, are used for body, propeller and other part of plane. In this present analysis, aluminium composite was fabricated with six different percentage of filler silica gel. The tensile and flexural moduli are calculated at three different speeds to examine the mechanical properties of composite. The results were computed by help of L18 orthogonal array. On the basis of Taguchi’s method, the plan of experiment was executed to perform test by taking two design factors, speed and percentage of filler. Using Taguchi optimization method, optimum combination of these two factors was found. Tensile modulus and flexural modulus were analyzed on ANOVA (ANalysis Of VAriance) and generate regression equation. To analyze tensile modulus and flexural modulus ‘Larger is Better’ was taken. In this analysis, it is observed that percentage of filler content is most dominating factor which affecting tensile modulus and flexural modulus. At last, the experimental results were validated by the confirmation tests.

Manufacturing Quality Improvement with Data Mining Outlier Approach against Conventional Quality Measurements

Background/Objectives : This research study has been conducted in a scientific way to help manufacturing engineers and the management team to find out the hidden information from the data which are generated during the everyday manufacturing process. Methods/Statistical analysis: The methodology adopted in this activity is applying outlier analysis which is a data mining technique. The inter quartile range findings and analysis has been used here to find the hidden useful information from the process data with which a better insight could be established towards the improvement of quality of the product. The data used here have been collected from the automotive engine assembly and testing process. The study compares the results between the conventional and outlier analysis. Findings: The conventional style of checking and approving the engines based on the value pattern of Specific Fuel Consumption (SFC) which uses the design specification comparison with the actual data generally yields very minimal scope for the improvement of product quality in the perspective of design, Safety and reliability of the product because of the adherence of the same design specifications of the part drawings supplied by various suppliers. The competitive automotive manufacturing domain demands a different approach with which a better scope could be identified towards the improvement of product quality which is undoubtedly data mining. The outlier analysis using inter quartile range on the sample data of 500 engines revealed many important aspects where the improvement scope for quality has been identified as 15,000 Parts Per Million (PPM) against400 PPM of conventional quality analysis for the same data. Improvement/Application: This research is to offer an inclusive model hypothetically with actual data both for engineering and management people of manufacturing domain about the insights and benefits of employing data mining techniques towards the improvement of product quality with proven results.

Operations strategies of engine assembly plants in the Brazilian automotive industry

Purpose– The purpose of this paper is to identify and analyze the operations strategies (OSs) adopted by six of the all seven automobile engine manufacturers in action in Brazil during the years of 2005 and 2006.Design/methodology/approach– Semi-structured interviews were held with at least one of the top managers at each engine manufacturing plant to collect information about the aforementioned strategies. The questions were aimed at identifying possible changes, over a four years period, in some of the operations-related competitive priorities and decision areas.Findings– This research revealed the strategies adopted by six of the all seven major automobile engine manufacturers installed in Brazil in 2005, enabling a discussion of relevant themes from both the theoretical and practical standpoints. Competitive priorities and decision areas form a very inter-related system and any significant change of OSs requires significant investments, effort and time.Research limitations/implications– Case studies were carried out in a specific context of the automobile market in Brazil in 2005 and 2006. Firms must treat operations as a system that changes continuously.Practical implications– In dealing with operations as a system, managers should know and apply OS concepts. This is even more important at dynamic (economic) sectors/industries.Originality/value– This paper describes and discusses – via qualitative research and in a comprehensive way – the OSs of two groups (established and entrant manufacturers) of firms in a relatively dynamic context in Brazil.

Non-majority North Carolina

Loud, dirty diesel engines move just about every load imaginable. Their smoke and roar are so ubiquitous that one’s brain almost does not register them; yet every piece of heavy construction equipment, every big-rig truck, every school bus, most boats, and many of the pickup trucks on the road run on diesel. And the engines are big business. Cummins, Inc., which manufactures and distributes diesel engines, reported a whopping $1.2 billion in profits for the third quarter of 2014; shares of its stock are expected to rise by as much as 15 percent this year. But that large pile of cash has not flowed equitably to the workers at Cummins’ engine assembly plant in Rocky Mount, North Carolina, one of eleven such Cummins facilities in the United States. The Rocky Mount plant, located in eastern North Carolina’s Black Belt, has about a thousand employees, with another three hundred or so temp and subcontracted workers doing everything from working the assembly line to providing housekeeping, painting, and other services for the plant. The Rocky Mount facility has a majority AfricanAmerican workforce. Globally, Cummins employs a workforce of 47,900 people. The Rocky Mount Engine Plant (RMEP) is nestled in the northeast quadrant of the leastunionized state in the country: just 2.9 percent of North Carolina’s workers belong to unions, and seven years after the start of the Great Recession, its unemployment rate remains among the highest in the nation. Against those punishing odds, and without a majority of workers signing union cards, thirty-year employee Jim Wrenn, who serves as president of the Carolina Auto, Aerospace & Machine Workers Union (CAAMWU), a branch of the United Electrical Workers (UE) Local 150, and his coworkers at RMEP have built a union anyway.

Grey Wolf Optimizer algorithm for the two-stage assembly flow shop scheduling problem with release time

This article addresses the two-stage assembly flow shop scheduling problem with release time of jobs which is applicable in many industrial areas, such as computer manufacturing industry, fire engine assembly plant, etc. The first stage of the problem is called “fabrication stage” and includes identical parallel machines while the second stage is called “assembly stage” with a single assembly machine. The jobs have components which they need to be firstly processed at the fabrication stage and then they should go under assembly operation at the assembly stage. The goal of this research is to find the jobs sequence such that completion time of the last processed job is minimized. For this problem, several heuristic techniques as well as a lower bound are developed. Also, a novel meta-heuristic algorithm called Grey Wolf Optimizer (GWO), which is inspired by living and haunting behavior of wolves, is then proposed. An extensive statistical analysis is conducted to compare the performance of the employed algorithms on randomly generated instances. The obtained results indicate that the methods based on Johnson’s algorithm yield better results than the other heuristic algorithms. Moreover, the consequences show that the proposed LB is tight enough. Finally, the experiments show that the GWO outperforms the other employed well-known meta-heuristic algorithms.

On the use of cyclostationary indicators in IC engine quality control by cold tests

This paper addresses the use of first- and second-order cyclostationary (CS1 and CS2) tools to process the vibration signals picked up from internal combustion (IC) engines during cold tests. This type of analysis is needed in order to detect and diagnose irregular operations for quality control purposes.The effectiveness of indicators such as Mean Instantaneous Power (MIP), Degree of Cyclostationarity (DCSα) and Indicator of Cyclostationarity (ICSnx) in detecting assembly faults has been tested on real signals concerning three faulty conditions: inverted piston, connecting rod with incorrectly tightened screws, connecting rod without one bearing cap. In the past several authors have mainly used cyclostationary metrics for diagnostics purposes in rolling bearings and gear systems.Moreover, a signal model, qualitatively reproducing the features of actual cold test signals, has been formulated and used in order to preliminarily study the influence of signal parameters on the Indicators of Cyclostationarity.The results indicate that the cyclostationary tools – mainly CS2 tools – are effective in detecting and diagnosing all tested faulty conditions. In particular, indicator IC⌢S2x is highly sensitive to faults and it is suitable as pass/fail tool in quality control at the end of the engine assembly line. As a further second-order cyclostationary metric, the MIP is effective for detection, as well for fault identification, since it is able to localize regular and fault events within the engine cycle. In addition DCSα effectively characterizes the CS2 periodicities, giving the cyclic order distribution. Since these CS2 tools require a moderate computation cost, they can be considered ready for on-line industrial applications.

The Engine Assembly Rules of Each Mode of Vibration Analysis

In This paper, on the basis of studying on relevant fields, three-dimensional factual model of engine assembly is established with SDRC/Ideas9 software according to the factual characteristic of engine structure. The fix frequency of engine assembly and parameters of main mode are acquired concerning with mode analysis, so that we can understand the rule of vibration. This approach can reduce the level of vibration and noise.

Systematic review: plantar fasciitis and prolonged weight bearing.

Plantar fasciitis (PF) is one of the most common causes of foot pain. Work can involve factors that may predispose to foot pain. To systematically review the evidence of the association between weight bearing (walking or standing) and PF among workers. Literature search of relevant indexing databases from inception to May 2012, grey literature, websites of relevant organizations and reference lists for all identified articles. Two reviewers independently selected studies for full review, assessed methodological quality and graded evidence. Findings were summarized qualitatively. Four studies were included; all were assessed as high or unclear risk of bias. Three studies were case-control studies; two used clinic populations and one used volunteers. The other study was cross-sectional involving the workforce of an assembly plant. A number of associations between PF and risk factors were identified including sex, obesity, foot biomechanics and job factors (e.g. job tenure). Two case-control studies and the cross-sectional study found an association with weight bearing, but the assessment of weight bearing varied (e.g. time on feet, time walking or standing). There was low-quality evidence to confirm a causal relationship (Royal College of General Practitioners (RCGP) * grade). This systematic review found low-quality evidence of an association between PF and weight-bearing tasks such as walking and standing on hard surfaces. The only occupations specifically identified as having higher risk were those associated with the engine assembly plant. Further research is required to fully determine the association between weight bearing and PF.

Impact of external interferences on vibroacoustic signals coming from combustion engine during cold test

In the paper is presented impact of external interferences on vibroacoustic signals coming from a spark ignition engine’s vibrations in cold test performed on engine assembly line. As the basis to the analysis were used signals of piezoelectric sensor mounted on cylinder block of the engine driven by electric motor. In course of the testing it has been used the order tracking analysis of the vibrations during the cold test, while experimental results were used to statistic analysis of significance of influence with use of the MiniTab computer program. The main objective of the investigations was to verify actually obtained vibroacoustic signals and to minimize interferences coming from the measuring system. It should contribute to reduction of tolerance limits and improved detection of faulty engines with use of vibroacoustic methods. The investigations have shown significant impact of contact surface of the cylinder block with the sensor and impact of deformations of compression spring on results of recorded vibroacoustic signal. Such impact should be taken into considerations in numerical analysis of the signal. It has been proposed to perform activities to reduce influence of the interferences on recorded signals. Results of the investigations have been already utilized in production cold tests of spark ignition engines.

Virtual Assembly of an Airplane Turbine Engine

This paper presents the virtual assembly of an airplane turbine engine and discusses the advantages of building virtual reality models in assembly process verification. The assembly parts and assembly sequence using a Virtual Reality Design system are explained. Virtual prototyping has come a long way in recent years, where current enviroments enable sterescopic visuals, surround sound, and ample interaction with generated models. In a virtual reality environment that is built with VR Software, the virtual prototype of a turbine engine is developed, and a simulation of movement of parts is conducted to illustrate assembly process planning.

CFD-modeling of processes in a high-pressure oxidizer pump for the turbopump assembly of a liquid rocket engine

The article presents CFD modeling of the work process in the oxidizer pump of a turbopump assemblyusing the ANSYS CFX software, as well as the comparison of numerical and theoretical calculations of theanalytical relations based on geometric data. Problems were encountered when modeling the flow of the pumpdue to inaccuracies in the drawing. The spherical radius in the area of the volute chamber throat had to bereduced, otherwise the model would not be topologically consistent with the original. The data on the vaneangles at the inlet and outlet of the centrifugal impeller were absent in the drawings. The blade angles weredetermined by the previously constructed geometric model. Negative pressure at the entrance of the impellervanes was found in the analysis of the first results of CFD-calculation. Increasing the number of elements in thispart of the calculation model made it possible to reduce the area of the negative pressure.CFD-modeling error with respect to the analytical solution does not exceed 11% by the parameters of total andstatic pressure. The results of the work can provide a visual representation of the processes taking place duringthe operation of the high-pressure pump of a turbopump assembly. The CFD-model can also be used for furtherresearch of work processes in liquid oxygen pumps to reduce the number of development tests.

Planning of synchronized assembly lines taking into consideration human performance fluctuations

Increasing demands on the flexibility of assembly workers has led to numerous times of high exposure rates within one workday. Inflexible processing times in synchronized assembly lines mismatch the individual, circadian variable work capacities of operators. As a result, frequent performance peaks due to limited possibilities for individualization elevate physiological and psychological workloads. This paper’s main objective is an individualization of assembly system performance requirements aimed at providing the opportunity to adapt current processing times to individual work capacities for reactively levelling the operators’ workload. On the one hand, the authors focus on defining requirements to enable a company to record valid current processing times within a synchronized assembly line. The authors provide a checklist aimed at generating sets of raw data specifying the necessary requirements. This checklist can be applied by the user of the approach. The authors provide an approach of statistical data processing to eliminate non-valid data-sets which do not allow inference on human performance fluctuations. On the other hand, the paper provides an approach for planning synchronized assembly lines taking into consideration human performance fluctuations. Based on defining performance and time characteristics, the authors methodically deduce one exemplary recommendation for the examined synchronized assembly lines quantifying the expected value for production periods. As a result, this combination leads to the possibility of methodically adapting systems’ performance requirements to fluctuating operators’ work capacity. Moreover, application of the presented approaches within a field study leads to an analysis and evaluation of significant production periods in a German car manufacturer’s engine assembly.

Assembly Line Balancing in Automobile Engine Industry

In this paper, under various constraints, based on LR series engine of automobile mixed model assembly line as an example, application of MMALB theory design automobile engine assembly line. To solve the multi-objective optimization problem, we establish the mathematical model between the workstation and workstation internal load balancing two optimization objectives. And engine assembly line is dynamic simulated by using the simulation software eM-Plant. The results verify the validity and practicability of the digital simulation. Finally, the planning scheme guarantees the whole assembly line load balancing and achieves production requirements.

The Design and Realization of HRA Service System for the Engine Assembly

Human error is a main factor causing the engine assembly quality defects. This paper presented the application of the Root Cause Retrospective Analysis (RCRA) of the Cognitive Reliability and Error Analysis Method (CREAM) in the engine assembly process, proposed a new model of the RCRA for engine assembly failure within the framework of HRA (Human Reliability Analysis) service system for the engine assembly. The application of the model was illustrated by an example. The research belongs to one of the core functions of HRA service system, which can be used to perform the human error analysis in the process of the engine assembly, so as to provide guidance for production.

Interactive Animation Construction in Virtual Environments

Current mechanical kinematic animation can’t satisfy the requirements of Virtual Environment (VE) based design. The kinematic animation design in VE development platform does not have high level models and mechanisms, the interactive animation designs and developments are very difficult and time consuming. For these reasons, this paper proposes an innovative method for interactive kinematic animation design and development in VE, including dynamic runtime model and execution algorithm for interactive animation. A complex mechanical kinematic mechanism, that is, the engine assembly, is built to validate the animation technology introduced in this paper.

Performance Evaluation of an Engine Assembly Line through Simulation

Simulation can be used in industrial field allowing the systems behavior to be learnt and tested. This work involves simulation and analysis of the engine assembly line. An engine assembly line contains three subsystems namely engine assembly, hot test line and paint shop. A simulation model built up in modeling software-WITNESS by considered entire set of data. The model validated and several what-if scenarios generated. The different scenario has been analyzed. Finally the throughput, optimum number of pallet and bottleneck identified. This paper discusses the need and uses of discrete event simulation in the design for final engine assemblies.

A Real Multi-Objective Bin Packing Problem: A Case Study of an Engine Assembly Line

This paper studies a real case of bin packing problems. The problem is inspired from a car manufacturer that aims at improving logistic activities of its engine assembly line. It is to plan transportations of parts from a warehouse to workstations. The first objective is to find the minimum possible motorized vehicles to conduct all the transportations. The second objective is to smooth the workload of vehickles to the maximum extent possible. To tackle the problem, it is first formulated in form of a mixed integer linear programming model. Then, a local-based greedy heuristic is proposed to solve the problem in large-sized cases.