Development of Heavy Duty Trailer Drawbar Utveckling av dragstång till tunga fordon Degree project in the Bachelor of Science in Engineering Programme Mechanical Engineering FILIP SANDBERG WILLIAM NORDKIL Department of Materials and Manufacturing Technology Division of Advanced Non-destructive Testing CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden, 2016 Examiner: Gert Persson Report No. 148/2016 PREFACE This report is a bachelor thesis which is the last part of our studies at the Mechanical Engineering program at Chalmers University of Technology with focus on machine design. The thesis comprises 15 credits and is executed at the institution Materials and manufacturing technology. The thesis has been done at ÅF in the HCT-project. We would like to give great thanks to Dennis Persson at ÅF who has been our supervisor in the project, without his support we would not been able to complete the thesis. Our thanks also go to Marcus Persson who has assisted with knowledge and support (when Dennis was not around). We would also like to thank our supervisor, Gert Persson, associate Professor and Deputy Head of Department at the institution Materials and Manufacturing technology, for the support and counsel. Gothenburg, June 2016 William Nordkil & Filip Sandberg SUMMARY ÅF AB is one of Sweden's largest consulting company that have a partnership in the automotive industry with Volvo AB to create longer and heavier truck combinations. Within this project their own trailers have been developed to create a 27,3 meter long vehicle combination which is one out of several vehicle combinations used in order to increase legal load and length restrictions within Sweden. This work focuses on the drawbar to the trailer which is a center axle trailer with a rigid drawbar. This work involves developing a new drawbar without the problems of today, where a withdrawal is made of the chassis frame sides lower flange to fit the drawbar, while maintaining strength and low weight. With a side track in developing proposals on the basis of the UNECE regulation R-55. The work started with feasibility studies as well as meetings and interviews with people familiar with the project and similar projects to get an idea of what is available today. This was done to get ideas for creating new concepts that are not already available today. A specification was developed with the help of data obtained from meetings and studies. The first sketches of concepts were designed and crossed to bring out new concepts. Then the created concepts were evaluated by CAD and FEM models using the CAD program Creo where stress images and calculations were inspected. A number of meetings were held to make and validate choices and designs. A winning concept was developed and several concepts with potential for development. To the Directive R-55 a best-case scenario was developed with the help of meetings with senior designers within the industry as well as an alternative solution when the best scenario may not be implemented. SAMMANFATTNING ÅF AB är ett av Sveriges största konsultföretag som har ett samarbete inom fordonsindustrin med Volvo AB för att skapa längre och tyngre lastbilskombinationer. Inom detta projekt har egna trailers tagits fram för att skapa en 27,3 meter lång fordonskombination, som är en av flera fordonskombinationer att göra tester på för att öka laglig last och längd inom Sverige. Detta arbete fokuserar på dragstången till lastbilssläpet som är en kärra med stel dragstång. Arbetet går ut på att ta fram en ny dragstång utan de brister som finns i dagens lösning med bibehållen hållfasthet och låg vikt. Med en sidogren att ta fram förslag på underlag till UNECE-direktivet R-55. Arbetet startade med förstudier samt möten och intervjuer med personer som är insatta i projektet och liknande projekt för att få en uppfattning av vad som finns på marknaden. Detta gjordes för att få idéer för att skapa egna nya koncept som inte redan finns idag. En kravspecifikation togs fram med hjälp av underlag som erhållits från möten och undersökningar. Efter brainstorming och matriser ritades enklare skisser upp och korsades för att få fram nya koncept. Därefter utvärderades koncepten genom CAD och FEM-modeller med hjälp av programmet CREO där spänningsbilder och beräkningar togs fram. Ett antal möten hades för att göra och validera, val och konstruktioner. Efter att ha tagit fram flera koncept med utvecklingspotential valdes några ut att utvecklas vidare innan ett slutgiltligt resultat togs. Till direktiv R-55 togs fram ett bästa scenario med hjälp av möten med seniora konstruktörer inom branschen samt en alternativ lösning då det bästa scenariot inte säkert går att implementera. Table of Contents Nomenclature ............................................................................................................................. 1 1 Introduction ........................................................................................................................ 2 1.1 Background .................................................................................................................. 2 1.2 Purpose ........................................................................................................................ 3 1.3 Delimitations ............................................................................................................... 3 1.4 Problem Statement ....................................................................................................... 4 2 Theoretical references ........................................................................................................ 5 2.1 Drawbars ...................................................................................................................... 5 2.1.1 Earlier drawbars ................................................................................................... 5 2.2 DUO Trucks ................................................................................................................ 6 2.3 Morphological Matrix .................................................................................................. 7 2.4 Concept screening matrix (Pugh) ................................................................................ 7 2.5 Kinnarps ....................................................................................................................... 8 2.5.1 Information about Kinnarps ................................................................................. 8 2.5.2 Study visit ............................................................................................................. 8 2.6 VBG-group .................................................................................................................. 9 2.6.1 R55 ..................................................................................................................... 10 2.6.2 RP:C203 ............................................................................................................. 10 3 Methodology .................................................................................................................... 11 3.1 Studying older drawbars and identifying customer needs ......................................... 11 3.2 Generate new concepts .............................................................................................. 11 3.3 Evaluate the R55 regulation for drawbars & couplings ............................................ 11 3.4 Development of concepts .......................................................................................... 11 3.5 Presentation of final concept ..................................................................................... 11 4 Gathering information ...................................................................................................... 12 4.1 Examining Trucks ...................................................................................................... 12 4.2 Requirements ............................................................................................................. 12 5 Concept Generation .......................................................................................................... 14 5.1 Brainstorming with use of a Morphological matrix .................................................. 14 5.2 Concepts generated .................................................................................................... 14 5.2.1 Concept 1 ............................................................................................................ 15 5.2.2 Concept 2 ............................................................................................................ 16 5.2.3 Concept 3 ............................................................................................................ 17 5.2.4 Concept 4 ............................................................................................................ 18 5.2.5 Concept 5 ............................................................................................................ 19 5.2.6 Concept 6 ............................................................................................................ 20 5.2.7 Concept 7 ............................................................................................................ 21 5.2.8 Concept 8 ............................................................................................................ 22 6 Evaluating sketches .........................................................................................................