Vibration Isolated Cabin on Reach Truck: Development and Verification
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
When a reach truck is driven over poor warehouse floors or obstacles such as thresholds, great vibrations and shocks occurs in the structure of the vehicle. These vibrations and shocks propagates almost undamped through the chassis, to the cabin and up to the overhead guard. This results in high stress levels in the welded components, which can lead to structural failure. It also results in unpleasant comfort for the driver. To improve this, a previous thesis have been conducted and it resulted in a concept where four rubber isolators are mounted between the cabin and the chassis. The future work recommendations were to follow up the concept, implement it on a full-scale reach truck and conduct tests, to verify the selected concept. That is where this thesis picks up from.In this work, vibrational analysis has been conducted with different tools to lay the foundation for a proper isolator selection. A standard reach truck’s layout has been modified to implement rubber isolators and make it possible for the cabin to vibrate freely. A full-scale reach truck prototype has been built. Two test series have been performed on a test truck, one before the modification for reference measurement and one after that the prototype were built.The tests shows that the stress levels in the cabin and the overhead guard is reduced by an average of 60% when driving 10 km/h over an obstacle. For a speed of 6 km/h the same stresses are reduced by 40%. Contrariwise, some of the acceleration levels in the cabin and the overhead guard are amplified up to +110% when traveling in 6 km/h. But, when driving at 10 km/h the amplitudes are generally reduced by -45%. It also shows that the isolation solution reduces frequencies over ~20 Hz, but amplifies the frequencies below. This concludes that the selected isolators do not have the optimal isolation efficiency, but a more efficient isolators could lower the overall quality impression on the reach truck due to softer mounts. However, the driving experience is enhanced and it opens up for more cost efficient design for Toyota Material Handling and higher productivity for the customers.
Place, publisher, year, edition, pages
2015. , 68 p.
Teknik, Vibration, isolation, damping, simulation, Adams, reach, truck, development, verification, test, testing, analysis, mechanical, mechanics, measurement, base, excitation, vehicle, design, prototype, eigenvalue, matlab, multibody, dynamics, isolator
IdentifiersURN: urn:nbn:se:ltu:diva-59068Local ID: f991e16f-1a69-4f5a-97e9-a074d6498286OAI: oai:DiVA.org:ltu-59068DiVA: diva2:1032456
Subject / course
Student thesis, at least 30 credits
Mechanical Engineering, master's level
Validerat; 20150924 (global_studentproject_submitter)2016-10-042016-10-04Bibliographically approved