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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Design of a Test Equipment : Quality Control on Hydraulic Quick Couplings Used in the Excavation Industry

Andersson, Daniel, Florbrant, Robin January 2020 (has links)
Construction machines use quick couplers to rapidly change the attached tool. The gear lets the machine operator control the hooking and unhooking of the tool from inside of the cabin. This saves time and makes construction work much easier for the workers. The quick coupler is most commonly used on excavators, placed at the outer end of the excavator arm. The tool which the quick coupler connects to needs to have an adapter welded on it for the coupling process to work. Both quick coupler and adapter are equipped with hydraulic quick couplings, the female halves in the quick coupler and the male halves in the adapter. They connect the distribution of hydraulic fluid from the machine to the tool. This master thesis, in industrial design engineering, is focusing on developing a test equipment that can ensure the quality of hydraulic quick couplings. The project is done in collaboration with the company Steelwrist, which requests that the equipment can detect if the couplings are leaking, in both connected and unconnected state, as well as, measuring the internal friction and spring forces that occur during the connection and disconnection.  The project was carried out through a design process with four phases, inspired by ‘the double diamond process’. The used process consists of three sessions of diverging and converging in the form of first widely exploring followed by taking focused actions. The focus in the first phase was to discover information about safety, quality, measurements and instruments, along with conducting interviews and observations in order to understand the current state at the company. In the second phase was the specification and workflow of the new test equipment defined. In the following phase the development of the test equipment started. First by generating hundreds of potential solutions to partial functions, which could be divided into five concepts that were parallely developed and evaluated. In the last phase was the best of the five concepts finalized and constructed in CAD, in order to deliver models and drawings on the final design.  The main focus in the developing and evaluating process has been to create a as safe product as possible. The positions needed to be performed by the operator were extensively investigated and the ergonomics were highly prioritized. Another important factor was the simplicity of the machine components of the test equipment. The project resulted in a complete solution for a new testing station, consisting of storage for adapters, spare parts and documents, along with the test equipment in the shape of a floor standing machine. The test equipment seals the hydraulic quick coupling half, which is meant to be tested, towards an adapter with a pneumatic cylinder. A servo motor then moves the opposite quick coupling half in order to enable the connection and disconnection. The last mentioned coupling half is attached to a load cell which measures the force. The existing leak detection instrument is connected to the test equipment in order to fill the test object with air in the different states. / Byggmaskiner använder snabbfästen för att snabbt byta det fastsittande verktyget. Redskapet låter maskinföraren styra på- och avkopplingen av verktyget från insidan av hytten. Detta sparar tid och gör konstruktionsarbetet mycket enklare för dem som jobbar. Snabbfästet används oftast på grävmaskiner, placerade längst ut på grävmaskinsarmen. Verktyget som snabbfästet ansluter till måste vara utrustad med en fastsvetsad grind för att kopplingsprocessen ska fungera. Både snabbfästet och grinden är utrustade med hydrauliska snabbkopplingar, honhalvorna i snabbfästet och hanhalvorna i grinden. De ansluter hydrauliken från maskinen till verktyget. Detta examensarbete inom teknisk design fokuserar på att utveckla en testutrustning som kan säkerställa kvaliteten på hydrauliska snabbkopplingar. Projektet utförs i samarbete med företaget Steelwrist, som begär att utrustningen ska upptäcka läckage i kopplingarna, både i anslutet och ej anslutet tillstånd, samt att mäta de interna friktion- och fjäderkrafter som uppstår under anslutning och frånkoppling. Projektet bestod av fyra faser, inspirerad av design processen 'the double diamond process'. De fyra faserna omfattar totalt tre sekvenser innehållande en divergerande del och sedan en konvergerande del i form av att först utforska brett, följt av att smalna av med mer fokuserat besluttagande. Fokus i den första fasen var att ta reda på information om säkerhet, kvalitet, mätningar och instrument, tillsammans med intervjuer och observationer för att förstå det aktuella tillståndet på företaget. I den andra fasen definierades specifikationer och arbetsflödet för den nya testutrustningen. I följande fas inleddes utvecklingen av testutrustningen. Först genom att generera hundratals potentiella lösningar på delfunktioner, som sedan kunde delas in i fem koncept som parallellt utvecklades och utvärderades. I den sista fasen färdigställdes det bästa av de fem koncepten och konstruerades i CAD så modeller och ritningar på den slutliga designen kunde levereras. Huvudfokuset i utvecklings- och utvärderingsprocessen har varit att skapa en så säker produkt som möjligt. De positioner som utförs av operatören undersöktes grundligt och ergonomin prioriterades högt. En annan viktig faktor var enkelheten i testutrustningens olika komponenter. Projektet resulterade i en komplett lösning för en ny teststation, bestående av lager för adaptrar, reservdelar och dokument, tillsammans med testutrustningen i form av en markplacerad maskin. Testutrustningen försluter den hydrauliska snabbkopplingshalvan, som är tänkt att testas, mot en adapter med en pneumatisk cylinder. En servomotor flyttar sedan motsatt snabbkopplingshalva för att möjliggöra anslutning och frånkoppling. Den sistnämnda kopplingshalvan är fäst på en lastcell som mäter krafterna som uppstår. Det befintliga läckagedetekteringsinstrumentet är anslutet till testutrustningen för att fylla testobjektet med luft i dem olika tillstånden.
62

Stavebně technologický projekt bytového domu ve Strážnici / Constructive technological project of block of flats in Strážnice

Rozumek, Jakub January 2015 (has links)
The theme of my diploma thesis is Building and Technological Project for a residential building in Strážnice. This is a study of the implementation of major technological stages of object SO- 01 residential building, the project concerning the construction site installation, design the mechanical assembly, traffic solutions, technological process earthworks, foundation structures, piles CFA and reinforced concrete ceiling construction. The work includes further object schedule, financial plan, a detailed timetable for construction of residential building, the budget, the inspection and the test plan, safety hazards on a construction site in the implementation of the substructure object and thermal technical assessment of selected structures.
63

Beitrag zur Analyse des Grabwiderstandes am Schaufelradbagger

Kreßner, Martin 02 March 2020 (has links)
Mit dem Anspruch, den Informationsgehalt heute standardmäßig erhobener Prozess- und Betriebsdaten mit beliebiger zeitlicher Auflösung für die Zwecke der Grabwiderstandsanalyse zu erschließen, wurde auf Grundlage der konventionellen Methode der indirekten Grabwiderstandsermittlung ein umfassendes mathematisches Modell der Gesamtheit aller Teilprozesse bei der schneidenden Gewinnung am Graborgan des vorschublosen Schaufelrad-baggers erarbeitet und bisher unberücksichtigte zeitabhängige Einflussgrößen integriert. Das Ziel der Anwendung der hochauflösenden indirekten Grabwiderstandsanalyse (HIG) auf verschiedene theoretische und praktische Aufgabenstellungen war die Prüfung der Ergebnisplausibilität sowie die umfassende Diskussion der Potentiale und Grenzen der Methode. Für die Schneidwerkzeugentwicklung ist die Anwendung der HIG die einzige Möglichkeit, ohne zusätzliche Kosten, Umbaumaßnahmen oder Betriebsstillstände den Einfluss von Werkzeugparametern unter betrieblichen Bedingungen zu analysieren. Für die theoretische Weiter¬entwicklung des Fachgebietes ermöglicht die Prozessmodellierung auf Basis beliebiger Zeitinkremente die umfassende Analyse konventioneller und spanunabhängiger Grabwiderstandskenngrößen.
64

Autonomous control of hydraulic mobile applications – a 21-ton excavator case study

Opperwall, Tim, Holter, Ben, Yardley, Simon 25 June 2020 (has links)
Automation of mobile construction and agricultural equipment has gained wide acceptance based on increases in productivity, safety, and precision; while also helping upskill operators. On construction equipment, after-market automation of earthmoving crawler dozers and graders has driven a conversion of machines to electro-hydraulic (EH) implement control and integration into digital worksites. Unlike the aforementioned machines, conversion of the excavator into a semi or fully autonomous machine presents significant challenges due to kinematics, variable loads, non-linear multi-function of implements, safety, and robustness. The present work demonstrates the retrofit of a pilot-operated 21-ton excavator and development of automated controls to address these challenges. The operator pilot joysticks and existing hydraulic system were retained, while adding capability for autonomous functionality with integrated hardware, controls, and kinematic solvers within a production viable environment. Autonomous features for path planning, multi-function actuator velocity control, EH controls, and safety were developed to prove the value of precise and low latency control hardware for EH excavator operation.
65

Research on efficient driving method of heavy hydraulic excavator boom

Xia, Lianpeng, Quan, Long, Ge, Lei, Hao, Yunxiao, Zhao, Bin, Li, Bin 25 June 2020 (has links)
There is a lot of gravitational potential energy waste when hydraulic excavators work, which seriously affects the efficiency of the whole machine and produces a large amount of emissions. In order to reduce the energy consumption and emissions of large hydraulic excavators which the boom is driven by two hydraulic cylinders, an integrated drive and potential energy recuperation principle is proposed. In the implementation, the original two-chamber hydraulic cylinders are replaced by three-chamber hydraulic cylinders with energy storage chambers, and the energy storage chambers are directly connected with the hydraulic accumulator. The dead weight of the working device is balanced by the initial hydraulic pressure of the hydraulic accumulator, and the gravitational potential energy is directly recuperated. A digital prototype is established for the simulation work to verify the energy-saving effect. Then a test prototype is constructed according to the simulation work. The standard 90° loading duty cycle tests show that compared with the standard hydraulic excavators of the same type, in the case of meeting the same digging force, the working efficiency of the excavator increases by 20.7% and the fuel consumption decreases by 17.1%. In terms of 8 hours of work per day, a single excavator can save fuel up to 47 L per day and reduce carbon dioxide emissions by 123.6 kg.
66

油圧ショベルにおける自動掘削アルゴリズムの有効性検証 / ユアツ ショベル ニオケル ジドウ クッサク アルゴリズム ノ ユウコウセイ ケンショウ

平野 貴司, Takashi Hirano 19 September 2020 (has links)
本研究では,油圧ショベルの効率の良い自動掘削を目的として,提案した自動掘削アルゴリズムを,個別要素法を用いた土壌モデルと油圧ショベルの動力学モデルを組みわせたシミュレーションモデルによって検証する.さらに,シミュレーションの実機検証を目的として,油圧で駆動する模型を用いて,縮小モデル実験機を構築し,提案した自動掘削アルゴリズムの実機検証実験を行う. / In this study, for the purpose of efficiency automatic digging of hydraulic excavators, the proposed automatic digging algorithm is verified by the simulation model that combines a soil model using the Distinct Element Method and a dynamic model of the hydraulic excavator. Furthermore, for the purpose of verifying by the actual excavator, a scale model experimental machine is constructed using a hydraulically operated model excavator, and the actual machine verification experiments of the proposed automatic digging algorithm are conducted. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University
67

Bytový dům U Vojanky – stavebně technologická příprava / Residential House at Vojanky - construction-technological preparation

Andres, Josef January 2013 (has links)
The content of this thesis is the construction project of technological of residential building U Vojanky in Prag. The new residential building is comprised of two parts that are interconnected by connecting neck. Author deals with the most important technology stages of construction that are processed in following parts of this thesis.
68

Viladům v Humpolci - stavebně technologický projekt / Villahouse in Humpolci - building and technological project

Březina, Vojtěch January 2016 (has links)
The work includes construction of a residential building technological project Villahouse Humpolec. Residential building has five floors with ten housing units. In the first above ground is a garage and workshop with separate entrance. The author discusses the main technological stages of construction, which are processed in the following sections of this paper.
69

Placement of Controls in Construction Equipment Using Operators´Sitting Postures : Process and Recommendations

Jalkebo, Charlotte January 2014 (has links)
An ergonomically designed work environment may decrease work related musculoskeletal disorders, lead to less sick leaves and increase production time for operators and companies all around the world. Volvo Construction Equipment wants to deepen the knowledge and investigate more carefully how operators are actually sitting whilst operating the machines, how this affects placement of controls and furthermore optimize controls placements accordingly. The purpose is to enhance their product development process by suggesting guidelines for control placement with improved ergonomics based on operators’ sitting postures. The goal is to deliver a process which identifies and transfers sitting postures to RAMSIS and uses them for control placement recommendations in the cab and operator environments. Delimitations concerns: physical ergonomics, 80% usability of the resulted process on the machine types, and the level of detail for controls and their placements. Research, analysis, interviews, test driving of machines, video recordings of operators and the ergonomic software RAMSIS has served as base for analysis. The analysis led to (i) the conclusion that sitting postures affect optimal ergonomic placement of controls, though not ISO-standards, (ii) the conclusion that RAMSIS heavy truck postures does not seem to correspond to Volvo CE’s operators’ sitting postures and (iii) and to an advanced engineering project process suitable for all machine types and applicable in the product development process. The result can also be used for other machines than construction equipment. The resulted process consists of three independent sub-processes with step by step explanations and recommendations of; (i) what information that needs to be gathered, (ii) how to identify and transfer sitting postures into RAMSIS, (iii) how to use RAMSIS to create e design aid for recommended control placement. The thesis also contains additional enhancements to Volvo CE’s product development process with focus on ergonomics. A conclusion is that the use of motion capture could not be verified to work for Volvo Construction Equipment, though it was verified that if motion capture works, the process works. Another conclusion is that the suggested body landmarks not could be verified that they are all needed for this purpose except for those needed for control placement. Though they are based on previous sitting posture identification in vehicles and only those that also occur in RAMSIS are recommended, and therefore they can be used. This thesis also questions the most important parameters for interior vehicle design (hip- and eye locations) and suggests that shoulder locations are just as important. The thesis concluded five parameters for control categorization, and added seven categories in addition to those mentioned in the ISO-standards. Other contradictions and loopholes in the ISO-standards were identified, highlighted and discussed. Suggestions for improving the ergonomic analyses in RAMSIS can also be found in this report. More future research mentioned is more details on control placement as well as research regarding sitting postures are suggested. If the resulted process is delimited to concern upper body postures, other methods for posture identification may be used.
70

Stavebně technologický projekt výstavby polyfunkčního domu lokalita Nová Nitra / Constructive-technological project of building polyfunktion house locality Nova Nitra

Malý, Filip January 2012 (has links)
The content of this thesis is the construction project of technological multifunctional building new locality Nitra the Slovak Republic. Individual points outline the project, which are dealt with in this thesis can be divided into subcategories, depending on the type of information provided. The first category can include items such as a technical report to the STP, which describes the basic information about the objects constructed building including the construction situation, location of the site including links to transport and technical infrastructure and rough timetable for the construction of all buildings. The second category can include no specific calculation and optimization outputs such as itemized budget polyfunctional house SO-07.03, drawing of the site including all buildings proposed site and their economic evaluation, sizing of utilities for supplying water and electricity construction site, design of building machines and mechanisms including determining the time of deployment, technological regulation for the implementation of monolithic roof structure, including financial balance sheets prepared by the deployment of slab formwork. The last category included in the thesis are legislative requirements that must be observed and kept in the course of the construction plan is constructed as a safety and health at work, including security risks drawn up, inspection and testing schedule for monolithic construction and a list of environmental risks that may arise during implementation.

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