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Viewing 1 to 30 of 566
2011-09-13
Technical Paper
2011-01-2273
Rohit Hippalgaonkar, Joshua Zimmerman, Monika Ivantysynova
This paper compares two different rule-based power management (PM) strategies, in terms of their resultant fuel consumptions, through a simulation study as applied to a hybrid hydraulic multi-actuator displacement controlled (DC) system. Specifically, the system analyzed is a mini-excavator, wherein the digging functions are powered using four variable displacement pump/motors - these units are also shared by the auxiliary functions. In addition, the on-board hydraulic energy storage device, or accumulator, is charged or discharged using an additional pump/motor, called the storage unit. A parallel architecture is used for the hybrid system wherein the additional pump/motor is on the engine shaft, running at the same speed as the engine (and the other four pumps). An aggressive and fast, digging cycle was used to size the storage unit and accumulator, as well as to compare the performance of the two different strategies.
2011-10-06
Technical Paper
2011-28-0096
Amit Pingle, Venkateswara Reddy, Sameer Jog, Anand Raj, Subrahmanyam Chiramana
Weight reduction in construction equipment is sought to achieve energy conservation and also to comply with the vehicle safety and compliance regulations, managing the weight distribution across the rear and the front end of the equipment to achieve the optimum balancing. Of late the thrust on product weight has increased along with reduced time to market, leading to increased usage of structural optimization methods. This has been further supported by the availability of high performance computing at relatively low cost. VOC and CTQ tools provided the motivation and initial screening of the design variables. The structural optimization software provides an integrated platform for analysis as well as optimization of components. In this work, an optimization tool has been used for size and shape optimization of a construction equipment assembly and a commercial FEA package was used for verification and validation of the results.
2012-11-25
Technical Paper
2012-36-0631
Guilherme Pedroto Magalhaes, Eduardo Gayer, Luiz Vercosa, Jules Slama
Brazil will soon host the two major sports events throughout the world: the Football World Cup and the Olympic Games. Therefore several ventures are in planning and some are already in implementation. The first phase of these projects is the deployment, where several activities of civil construction are developed. The activities in general are developed in consolidated urban areas, treating very often modification of an urbane important installation. Thus, in this initial phase are executed activities of demolition, cleaning, preparing the land, foundation and piling, which are considered noisy for people, causing great discomfort to the existing community around the construction site. The objective of this paper is to present some information about the noise generated by the activities of civil construction and how to manage the environmental impact sound generated by the machinery and equipment used in these activities.
2012-09-24
Technical Paper
2012-01-1965
Piotr Lijewski, Jerzy Merkisz, Pawel Fuc
The paper discusses the measurement of the PM emissions from non-road vehicles (a farm tractor and an excavator) under actual operating conditions. Full exploration of the relations between the operating parameters of these vehicles and their emissions requires measurements under actual conditions of their operation. The specificity of the emission measurements, PM in particular, requires technologically advanced measuring devices. The situation gets even more complicated if, beside the PM mass, we also wish to obtain the PM size distribution and particle number (PN). One of the more important technical issues is the difficulty in fitting of the measurement equipment in/on the vehicle in operation (e.g. a farm tractor). That is the reason why the investigations were carried out in a laboratory. The laboratory technicians applied load to the engines through external devices - a hydraulic system for the excavator and a brake coupled to the farm tractor power takeoff.
2012-09-24
Technical Paper
2012-01-2040
Gabriele Altare, Damiano Padovani, Nicola Nervegna
The paper addresses some aspects of an ongoing research on a commercial compact excavator. The interest is focused on the analysis and modelling of the whole hydraulic circuit that, beside a load sensing variable displacement pump, features a stack of nine proportional directional control valves modules of which seven are of the load sensing type. Loads being sensed are the boom swing, boom, stick and bucket, right and left track motors and work tools; instead, the blade and the turret swing users do not contribute to the load sensing signal. Of specific interest are the peculiarities that were observed in the stack. In fact, to develop an accurate AMESim modelling, the stack was dismantled and all modules analysed and represented in a CAD environment as 3D parts. The load sensing flow generation unit was replaced on the vehicle by another one whose analysis and modelling have been developed using available design and experimental data.
2012-09-24
Technical Paper
2012-01-2042
Paolo Casoli, Alvin Anthony, Luca Ricco
This paper describes the results of a study focused on the mathematical modeling of an excavator hydraulic system. From the viewpoint of designing and tuning an efficient control system, the excavator is a very complex nonlinear plant. To design and tune such a complex control system an extremely good nonlinear model of the plant is necessary. The problem of modeling an excavator is considered in this paper; a nonlinear mathematical model of an excavator has been developed using the AMESim® modeling environment to replicate actual operating conditions. The excavator model is described by detailed models of the main pump, valve block and kinematic model. The objective of this research is to develop a complete simulation model of an excavator with the capability of reproducing the actual characteristics of the system. The model could then be used as a platform to facilitate the study of alternate control strategies towards energy efficient systems and new controller designs for HIL.
2012-09-24
Technical Paper
2012-01-1910
Michael Karge
By the fatigue assessment of large welded steel structures such as construction machines structures, the calculation engineer is confronted with a difficulty: the local stress approaches with fictitious notch radius that are very accurate cannot be used on the global structure because of the current computer limitations. Only a nominal stress can be estimated on the whole structure. The accuracy of the current commercial code methods that are using the nominal stress approach is not satisfying for most of the cases. The major problems are the following: only one SN-Curve (FAT-class) can be chosen for a weld the stress used for the calculation is based on the critical plane concept, not taking into account the direction of the weld (anisotropy of notch effects) and the geometrical weld parameters (e.g. weld throat thickness and penetration) choice of the FAT-class when the structural detail is not available in the IIW guideline.
2017-01-10
Technical Paper
2017-26-0230
Timothy Dallmann, Zhenying Shao, Aparna Menon, Anup Bandivadekar
Abstract Diesel engines used in non-road vehicles and equipment are a significant source of pollutant emissions that contribute to poor air quality, negative human health impacts, and climate change. Efforts to mitigate the emissions impact of these sources, such as regulatory control programs, have played a key role in air quality management strategies around the world, and have helped to spur the development of advanced engine and emission control technologies. As non-road engine emissions control programs are developed in a growing number of countries around the world, it is instructive to look at the development of programs in two of the regions that have progressed furthest in controlling emissions from non-road engines, the United States (U.S.) and European Union (EU).
2017-01-10
Technical Paper
2017-26-0234
Arun Narayanan, Sagar Bhojne
Abstract In Earth Moving Machines, performance of an attachments play crucial role in determining the machine performance. Application of the machine is one of the main factors to be considered for bucket design. Different types of buckets are offered in the market to suit the particular application. Trenching, digging, moving loose material are some of the operations done with the backhoe bucket. While operating in these areas bucket handles intact soil, granules, loose rocks etc. Properties of these materials play important role in bucket design methodology. In this paper efforts are made towards understanding the properties of soil along with soil failure mechanism and utilizing these inputs to design a backhoe bucket for better machine productivity. Mathematical modeling and Discrete Element Modeling (DEM) are the tools used for design and validation of this work.
2015-09-29
Technical Paper
2015-01-2851
Aleksandar Egelja, Darren Allan Blum, Kalpesh N. Patel
Abstract Many off-highway machines, including hydraulic excavators, perform cyclical motion in their everyday activities where there is significant acceleration, deceleration, load lifting and hydraulic implement lowering. During that time in conventional off-highway machinery, most of the potential or kinetic energy is dissipated as heat instead of being captured and reused. When these opportunities are well understood and consequently machine systems are designed and integrated properly, fuel efficiency improvements could reach double digit values. It should be noted that the mentioned machine efficiency improvements will still vary depending on the machine size, its application and the characteristics of machine system(s) being applied. An approach for excavator energy flow analysis, coupled with rapid machine control design changes directed to minimization of energy losses is discussed.
2014-05-07
Technical Paper
2014-36-0008
Torbjörn Narström
Abstract The use of modern quenched and tempered steels in dumper bodies to reduce weight to increase the payload and reduce the fuel consumption is briefly discussed. Modern quenched and tempered steels in combination with adopted design concept will further increase weight savings of the dumper body. Use of these materials may lead to 4 times longer wear life than ordinary steels. One of the main load cases for a dumper body is impact of an object, i.e. boulders and rocks, into the body. A well-proven test setup is used to develop a model to predict failure and depth of the dent after the impact. A material model with damage mechanic was utilized to predict fracture. The developed model was used to study the effect of the geometry of the impacting object, thickness of the plate and unconstrained plate field. The model was also implemented in larger model and compared with a full scale test of dumper body.
2016-04-05
Technical Paper
2016-01-0469
Hyunkoo Kang, Wooyong Jung, Choon Lee
Abstract This paper presents payload estimation based on experimental friction coefficients identification. To estimate exact payload mass, dynamic mathematical model such as actuator dynamics and front linkage dynamics is derived by using Newton-Euler method. From the dynamic equation, nonlinear terms are analyzed and transformed. And a friction model is derived from the experiments with various conditions which have three states; boom joint angle, head and rod chamber pressures. It can identify friction coefficients and compensate friction forces. In addition, the accuracy of payload estimation system is verified through the field test.
2015-01-14
Technical Paper
2015-26-0148
Jagadeesh Selvaraj, Dayalan Purushothaman, P T Haridas
Abstract Fuel economy is an important customer requirement which determines the position of earth-movers such as backhoe loaders in the market. Earth-movers are heavy duty machines that are used for construction works. Currently fuel consumption in earth-movers is quantified as fuel consumed per unit time (Liters per hour). Similarly, conventional measure of productivity of the earth-movers is in terms of volume of soil trenched per hour. Measurements using the above scales showed wide variations in measured fuel consumption and productivity, For the same equipment between measurements Two equipment of same make at different trench locations and Against the competitor equipment This inconsistency and lack of a proper measuring system made logical decision making extremely difficult. This paper describes the step by step procedures involved in deriving the methodology for robust fuel consumption measurement of earth-mover vehicles.
2015-09-29
Technical Paper
2015-01-2855
Massimiliano Ruggeri, Giorgio Massarotti, Pietro Marani, Carlo Ferraresi
Abstract Losses reduction and oil flow optimization management in construction machines and, in general, in heavy duty vehicles are two of the most challenging missions of today fluid power research. One of the most promising ideas is to implement multiple hydraulic power sources but this requires a flexible pump switch system; in fact, depending on flow request and machine mode, one or more pumps can be switched to serve each actuator. To put into practice these concepts it is necessary to in-depth design the distribution system, through which hydrostatic transmissions supply the different loads. The new component here presented realizes the pump switch management, creating a matrix framework of the hydraulic flow connections. Putting this concept it into practice the new architecture is able to connect alternatively a pump to one actuator at a time providing also for cross connections, enabling different sources flow summation.
2016-09-27
Technical Paper
2016-01-8114
Massimiliano Ruggeri, Pietro Marani, Michele Selvatici
Abstract Stationary (parking) brake is a very important and safety critical function in many classes of machines. The new transmissions and the “by wire” systems increase the criticality of the role of stationary brake, as it is also an emergency (secondary) brake, and it’s often used to hold the vehicle when the transmission is not locking the wheels. As an example, dual clutch and power-shift transmission gear systems, as well as hydrostatic transmissions under certain circumstances, are often unable to hold the vehicle stopped and this function is provided by the stationary brake. Due to the main need of having the brake actuated when vehicle is stopped, without any hydraulic and electric power, the brake configuration is normally a “negative” configuration, usually called “spring applied” because of the actuator configuration, but this configuration causes the brake actuation when de-energized, even in case of system failure.
2016-09-27
Technical Paper
2016-01-8126
Kamal Bathaee, Morteza Gholami
Abstract The aim of this paper is represented design and manufacturing process of change of functioning of a scrapped shovel (Ruston Bucyrus R32) to a lattice boom crane of 300-ton capacity. Capabilities of the structure, changed components, additional required components (e.g. boom, mast, winch…) and modifying critical dimensions of this shovel were surveyed. In this paper, some of the 300-ton capacity lattice boom cranes of various companies were considered and critical dimensions that play an important role in system stability were surveyed. After that, their major dimensions were compared with those of a common shovel. In order to design the structure and components of this shovel-based crane, static, dynamic and wind loads were calculated. Finally, the critical dimensions of the shovel related to chassis and crawler were modified.
2016-09-27
Technical Paper
2016-01-8127
Kamal Bathaee, Morteza Gholami
Abstract The aim of this paper is to establish the design process of a system that expedites concreting, the Topbelt. Two connected conveyors that provide five degrees of freedom are known as the Topbelt System. These two conveyors are suspended via a rope connection to a Lattice boom of a crane, Manitowoc 4100 S. The required concrete that should be handled by Topbelt is provided by a feeder. The suspended Topbelt system is capable of transporting concrete to levels of both higher and lower than the ground horizontal level. This concreting mechanism sweeps a circle of about 85-meter diameter, centering at the crane swing on the swing plane level. The Topbelt is suspended using two winches, one of them is for keeping conveyor1 in its proper position and the other is applied to keep conveyor2 by a rope guide mechanism, which allows the rotational movement of conveyor2 with respect to conveyor1. Expediting concrete process in dam construction is the main advantages of the Topbelt system.
2016-09-27
Technical Paper
2016-01-8121
Riccardo Bianchi, Addison Alexander, Andrea Vacca
Abstract Typically, earthmoving machines do not have wheel suspensions. This lack of components often causes uncomfortable driving, and in some cases reduces machine productivity and safety. Several solutions to this problem have been proposed in the last decades, and particularly successful is the passive solution based on the introduction of accumulators in the hydraulic circuit connecting the machine boom. The extra capacitance effect created by the accumulator causes a magnification of the boom oscillations, in such a way that these oscillations counter-react the machine oscillation caused by the driving on uneven ground. This principle of counter-reacting machine oscillations through the boom motion can be achieved also with electro-hydraulic solutions, properly actuating the flow supply to the boom actuators on the basis of a feedback sensors and a proper control strategy.
2017-05-10
Technical Paper
2017-01-1933
Werner Seifried
Concerning the limitation of greenhouse gases, the Kyoto protocol in 1997defined the first hard facts. A steady increase in the number of participating states as well as a rigorous focus on emission limits - even if some important countries did not sign or withdraw from the protocol - led to high pressure on existing technologies. The presentation therefore will start by discussing the four pillars of possible CO2 reduction options and will lead to the question why there is a correlation to assistance systems on hydraulic excavators. Finally innovative excavator assistance systems and their support to the objectives on CO2 reduction will be presented.
2017-05-10
Technical Paper
2017-01-1936
Ulrich Fass, Jenny Elfsberg
Abstract No abstract available.
2017-05-10
Technical Paper
2017-01-1922
Wolfgang Burget
Highly diversified market needs, non-harmonized regulations and new technological trends in future construction machinery industry will challenge OEMs in defining their appropriate development strategies. Main trends like “efficiency”, “safety/security” as well as “connectivity” are considered as important driving forces in future product - and customer service - developments. Some examples are given for the above mentioned trends. Chances and related risks of such development trends are considered as well.
1934-01-01
Technical Paper
340093
L. M. K. Boelter, D. D. Davis, W. L. Fons, D. O. Rusk
HEADLAMP construction is presented in summarized form, twelve needful factors being stated by the authors. Accelerated mechanical tests, which are designed to give within a few days results of what may be expected to take place after several years of road service, are conducted in the Headlight Laboratory of the University of California. These are described and illustrated under the headings: Vibration, durability, moisture, dust and electrical insulation, and the results are stated. A few correlation tests are commented upon. Headlamp vibration is treated at length, together with an analysis of headlamp vibration-characteristics, and a differentiation is made between vibration due to the engine and that due to roadway shocks.
2014-04-01
Technical Paper
2014-01-1715
Parul Goyal, Feng Liang, Olof Oberg
Abstract The aim of the paper is to describe how Volvo Construction Equipment uses a virtual product development process to analyze potential risks, find root causes and optimize future product development. A model based method is used to analyze a potential risk in the design of Wheel Loader transmissions. The risk was recognized from failure mode and effect analysis (FMEA), and a simulation model using AMESim modeling tool was developed to analyze the behavior of the new design. Together with test rig result, it is proved that the model based method gives a considerably accurate prediction of the system behavior. By using the model based approach, lead time for development process is reduced and important feedbacks from simulation model are obtained on early stage of the development. This paper further presents the use of the simulation model as a tool to predict the potential risks in the extreme operating conditions, which are difficult to test on the vehicle test bench.
1958-01-01
Technical Paper
580311
ALBERT H. HETZEL, CLAUDE B. PETTY
1959-01-01
Technical Paper
590136
E. M. WILSON
1957-01-01
Technical Paper
570135
F. J. STRNAD
1955-01-01
Technical Paper
550055
HOWARD KER
1955-01-01
Technical Paper
550047
E. A. NIX
1957-01-01
Technical Paper
570031
SINCE 1954 the CIMTC Subcommittee has been engaged in a program to meet military requirements through industry's production of construction equipment which can give satisfactory cold weather performance down to temperatures of −65 F. Individual contracts for three crawler tractors and one motor grader were negotiated by ERDL for these projects, and their performance is discussed. Industry participation was subsequently expanded to include engineering tests in the cold weather conditions of the Mesabi Iron Range. This joint report of the Winterization Sub-committee of the CIMTC and ERDL Winterization Section consists of separate papers by various members and consultants of this Sub-committee and ERDL personnel.
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