پديد آورنده :
لطفي، داوود
عنوان :
طراحي ، ساخت و ارزيابي دستگاه دينامومتر اتصال سه نقطه اي
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
مكانيك ماشينهاي كشاورزي
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي
صفحه شمار :
شانزده، 121ص .: مصور، جدول، شكل، نمودار
استاد مشاور :
جليل رضوي، محمدرضا اخوان صراف
توصيفگر ها :
ادوات دنباله بند، كشيدني ، سوار/ مالبندي تراكتور/ دينامومتر/ تنش لودسل ها/ مش بندي/ بارگذاري / لودسل ها/ اندازه گيري الكترونيكي / كرنش سنج ها/ دستگاه اينستران /
تاريخ نمايه سازي :
16/01/84
استاد داور :
حسن خادمي زاده، جواد زركوب
تاريخ ورود اطلاعات :
1396/10/25
چكيده فارسي :
به فارسي و انگليسي قابل رويت در قسمت " نسخه ديجيتال "
چكيده انگليسي :
Abstract Nowadays many of field operation in Iran is performed by the combination of tractor and draft implements Data suchas agricultural implement draft force and drawbar power requirements for optimum loading of tractor the only mobile power source in agriculture There for suitable selection of implements with regard to size for available tractors in Iran are very important For obtaining this information we need to have precision instruments such as three point hitch dynamometersfor measuring tractor velocity Farm type three point hitch dynamometer with the ability to match itself with various tractors have more advantagesthan the link type ones In this researchfor the first time in Iran a farm type three point hitch dynamometer is designed built and evaluated Forces applied to dynamometer are measured by three separateload cells located on a farm witch can be attached to tractor s three point hitch Each dynamometer s load cell measuresload with a strain gauge bridge circuit Each load cell was calibrated with applying a known load and measuring bridge circuit s output voltage Dynamometer was calibrated by the application of known forces and the output voltage of the strain gauge bridges was measured The calibration showed the high degree of linearity between the applied forces and the bridge on outputs The histersis effect between loading and unloading was small 1 5 The interaction of orthogonal forces on the response of longitudinal force measuring bridge was generally found to be less then 3 For measuring actual tractor velocity a fifth wheel by using an encoder rotational shaft was designed and built The calibration on asphalt and soil surfacesshowed a high linear relation between measured forward velocities and output of encoder s rotation The errors in speedmeasurementsat low speedsin field were 3 and at high speeds up to 12 5 krn h on asphalt surface was approximately 8 The data acquisition system in addition to display of instantaneous force and velocity can show Force time and Force displacementcurves on the system monitor For evaluating the entire system at the field condition the draft force of a rigid shank cultivator working t depth of 12 cm in a loamy soil was measured using a completely randomized block design at three forward velocities first second and third high gearsof MF 285 Messy Fergosentractor with five replication Results showed that there was not significant different replication but the rigid shank cultivator s draft force and power requirements increased linearly with forward velocity The three point hitch dynamometer can measure draft force of standard or non standard semi mounted and drawbar implements which are built in Iran in addition to the mounted implements of categories I and II I J t I I U 11 Lf I Jt A J q
استاد مشاور :
جليل رضوي، محمدرضا اخوان صراف
استاد داور :
حسن خادمي زاده، جواد زركوب