Detta examensarbete har gjorts på uppdrag av Rottne Industri AB och berör matarhjulens dubbinträngning i virket. Matarhjulen sitter monterade i skördaraggregatet i skördaren, en skogsmaskin som används vid skogsavverkning. Då inträngningen, som uppstår av dubbarna på matarhjulen, är för stor (>5mm) bildas skador på virket vilket är ett utbrett problem inom skogsmaskinindustrin. Studien kartlägger de vanligaste dubbmönstrens skadeåverkan under kontrollerade och vetenskapliga förhållanden där testerna är designade för att efterlikna verklig skogsavverkning. I studien utförs två tester. Det första visar sambandet mellan presskraft och inskjutningsmått för respektive dubbmönster. Det andra är utformat för att se förmågan att överföra kraft mellan dubbmönstret och virket, så kallad skjuvdragning. Sju dubbmönster kommer att undersökas i studien. Om man ser till den tekniska information utvunnen ur testerna så har finnskogsvalsen med dubbla ribbor ett klart övertag speciellt i skjuvningssituationer. Däremot måste fler aspekter tas med i beräkningarna vid valet av dubbmönster. En av dem är tendenser för barkpackning i mönstrets håligheter. Då finnskogsvalsen med dubbla ribbor är ett förhållandevis tätt mönster måste omfattande undersökningar göras angående den aspekten innan det kan tas i fullt bruk. / This diploma work has been done on commission by Rottne Industri AB and affects the feed rollers and their stud’s penetration in timber. The feed rollers are mounted in the harvester head which sits on a timber cutting machine used for harvesting wood (harvester). When the damage caused by the studs is too deep the timber is permanently damaged which is a big problem for the industry. Two tests is carried out in the study. The first shows the connection between the pressing force and the damage depth made by the studs. The second test is designed to show the stud patterns ability of transferring power from the feed rollers to the timber. Seven stud patterns are examined in this study. According to the technical information retrieved by the tests finnskogsvalsen with double ribs has the best characteristic abilities, especially in the pull test. But more aspects has to be dealt with before this pattern can be used in the reality. One obvious problem this stud pattern could have is a tendency to store bark during operation, this is a major problem in the woods.

<p>Detta examensarbete har gjorts på uppdrag av Rottne Industri AB och berör matarhjulens dubbinträngning i virket. Matarhjulen sitter monterade i skördaraggregatet i skördaren, en skogsmaskin som används vid skogsavverkning. Då inträngningen, som uppstår av dubbarna på matarhjulen, är för stor (>5mm) bildas skador på virket vilket är ett utbrett problem inom skogsmaskinindustrin. Studien kartlägger de vanligaste dubbmönstrens skadeåverkan under kontrollerade och vetenskapliga förhållanden där testerna är designade för att efterlikna verklig skogsavverkning.</p><p>I studien utförs två tester. Det första visar sambandet mellan presskraft och inskjutningsmått för respektive dubbmönster. Det andra är utformat för att se förmågan att överföra kraft mellan dubbmönstret och virket, så kallad skjuvdragning. Sju dubbmönster kommer att undersökas i studien.</p><p>Om man ser till den tekniska information utvunnen ur testerna så har finnskogsvalsen med dubbla ribbor ett klart övertag speciellt i skjuvningssituationer. Däremot måste fler aspekter tas med i beräkningarna vid valet av dubbmönster. En av dem är tendenser för barkpackning i mönstrets håligheter. Då finnskogsvalsen med dubbla ribbor är ett förhållandevis tätt mönster måste omfattande undersökningar göras angående den aspekten innan det kan tas i fullt bruk.</p> / <p>This diploma work has been done on commission by Rottne Industri AB and affects the feed rollers and their stud’s penetration in timber. The feed rollers are mounted in the harvester head which sits on a timber cutting machine used for harvesting wood (harvester). When the damage caused by the studs is too deep the timber is permanently damaged which is a big problem for the industry.</p><p>Two tests is carried out in the study. The first shows the connection between the pressing force and the damage depth made by the studs. The second test is designed to show the stud patterns ability of transferring power from the feed rollers to the timber. Seven stud patterns are examined in this study.</p><p>According to the technical information retrieved by the tests finnskogsvalsen with double ribs has the best characteristic abilities, especially in the pull test. But more aspects has to be dealt with before this pattern can be used in the reality. One obvious problem this stud pattern could have is a tendency to store bark during operation, this is a major problem in the woods.</p>

Due to the importance of a correct tree placement and the wear that occurs to equalizer bars inharvester heads, Komatsu Forest AB in Umeå was interested if the bar could be replaced with ahydraulic system. According to Komatsu, the problems were that the equalizer bars that are responsible forsynchronizing the delimbing knives and feeding mechanism add weight, take up space and have atendency to break before their life expectancy. Some harvester heads do not possess equalizer barsbut this complicates tree length and diameter measurements, risks increasing wear to parts of theharvester head not designed to be in contact with the trees and makes cutting the tree correctlymore difficult during certain actions. Thus, Komatsu saw a potential opportunity to increase thefeeding mechanisms performance and life span through a hydraulic solution. In this thesis, a literature study investigating practiced solutions to similar systems as well asa previous study by Komatsu in the subject are included. Furthermore, the product design process,implementation and verification of the solution are covered. The resulting solution included two Parker A2N0029D2H Series 3000 accumulators and fourParker DSH083NV valves, coupled in parallel pairs to create two arrangements of the final conceptsystem, “Half Control Remastered”; “regenerative coupling force distributor” and “shut off valveflow divider”. During the testing both the Regen and shut off function, mounted on a Komatsu C164harvester head, were observed to help during tree picking, grasping and feeding, but both functions,unfortunately, had disadvantages. The Regen function was unstable since hydraulic flow occurredfrom one cylinder to the other, and the Shut off function was imprecise because it became “choppy”with increased accuracy. While testing the system arranged with the Shut off function in the forest,it assisted during slow feeding as well as feeding while simultaneously forcing rotation, where theharvester head tended to drop trees. However, the system did little to no difference as soon thedelimbing knives were deployed. The results that are revealed in this thesis are difficult to evaluate, since Scandinavian forestharvester drivers do not challenge the harvester head in a way for the hydraulic equalizer barsystem to assist to its full potential. To conclude, the system shows promise to meet Komatsu’sperformance requirements but further testing and development is necessary for it to become refinedenough to implement in their mass produced harvester heads.